Merge pull request #43 from matrix-org/pedroc/android_e2e_dev

Android wrappers for olm library

28 files changed, 5551 insertions, 0 deletions

diff --git a/android/olm-sdk/src/main/AndroidManifest.xml b/android/olm-sdk/src/main/AndroidManifest.xml
new file mode 100644
index 0000000..902f2e3
--- /dev/null
+++ b/android/olm-sdk/src/main/AndroidManifest.xml
@@ -0,0 +1,8 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.matrix.olm">
+
+    <application
+        android:allowBackup="true"
+        android:label="@string/app_name">
+    </application>
+</manifest>
diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/CommonSerializeUtils.java b/android/olm-sdk/src/main/java/org/matrix/olm/CommonSerializeUtils.java
new file mode 100644
index 0000000..229963f
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/CommonSerializeUtils.java
@@ -0,0 +1,83 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.olm;
+
+import android.util.Log;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
+/**
+ * Helper class dedicated to serialization mechanism (template method pattern).
+ */
+abstract class CommonSerializeUtils {
+    private static final String LOG_TAG = "CommonSerializeUtils";
+
+    /**
+     * Kick off the serialization mechanism.
+     * @param aOutStream output stream for serializing
+     * @throws IOException exception
+     */
+    protected void serialize(ObjectOutputStream aOutStream) throws IOException {
+        aOutStream.defaultWriteObject();
+
+        // generate serialization key
+        byte[] key = OlmUtility.getRandomKey();
+
+        // compute pickle string
+        StringBuffer errorMsg = new StringBuffer();
+        byte[] pickledData = serialize(key, errorMsg);
+
+        if(null == pickledData) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_SERIALIZATION, String.valueOf(errorMsg));
+        } else {
+            aOutStream.writeObject(new String(key, "UTF-8"));
+            aOutStream.writeObject(new String(pickledData, "UTF-8"));
+        }
+    }
+
+    /**
+     * Kick off the deserialization mechanism.
+     * @param aInStream input stream
+     * @throws Exception the exception
+     */
+    protected void deserialize(ObjectInputStream aInStream) throws Exception {
+        aInStream.defaultReadObject();
+
+        String keyAsString = (String)aInStream.readObject();
+        String pickledDataAsString = (String)aInStream.readObject();
+
+        byte[] key;
+        byte[] pickledData;
+
+        try {
+            key = keyAsString.getBytes("UTF-8");
+            pickledData = pickledDataAsString.getBytes("UTF-8");
+
+            deserialize(pickledData, key);
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_DESERIALIZATION, e.getMessage());
+        }
+
+        Log.d(LOG_TAG,"## deserializeObject(): success");
+    }
+
+    protected abstract byte[] serialize(byte[] aKey, StringBuffer aErrorMsg);
+    protected abstract void deserialize(byte[] aSerializedData, byte[] aKey) throws Exception;
+}
diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmAccount.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmAccount.java
new file mode 100644
index 0000000..26c3e60
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmAccount.java
@@ -0,0 +1,415 @@
+/*
+ * Copyright 2017 OpenMarket Ltd
+ * Copyright 2017 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.olm;
+
+import android.text.TextUtils;
+import android.util.Log;
+
+import org.json.JSONObject;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+import java.util.Map;
+
+/**
+ * Account class used to create Olm sessions in conjunction with {@link OlmSession} class.<br>
+ * OlmAccount provides APIs to retrieve the Olm keys.
+ *<br><br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmAccount extends CommonSerializeUtils implements Serializable {
+    private static final long serialVersionUID = 3497486121598434824L;
+    private static final String LOG_TAG = "OlmAccount";
+
+    // JSON keys used in the JSON objects returned by JNI
+    /** As well as the identity key, each device creates a number of Curve25519 key pairs which are
+     also used to establish Olm sessions, but can only be used once. Once again, the private part
+     remains on the device. but the public part is published to the Matrix network **/
+    public static final String JSON_KEY_ONE_TIME_KEY = "curve25519";
+
+    /** Curve25519 identity key is a public-key cryptographic system which can be used to establish a shared
+     secret.<br>In Matrix, each device has a long-lived Curve25519 identity key which is used to establish
+     Olm sessions with that device. The private key should never leave the device, but the
+     public part is signed with the Ed25519 fingerprint key ({@link #JSON_KEY_FINGER_PRINT_KEY}) and published to the network. **/
+    public static final String JSON_KEY_IDENTITY_KEY = "curve25519";
+
+    /** Ed25519 finger print is a public-key cryptographic system for signing messages.<br>In Matrix, each device has
+     an Ed25519 key pair which serves to identify that device. The private the key should
+     never leave the device, but the public part is published to the Matrix network. **/
+    public static final String JSON_KEY_FINGER_PRINT_KEY = "ed25519";
+
+    /** Account Id returned by JNI.
+     * This value identifies uniquely the native account instance.
+     */
+    private transient long mNativeId;
+
+    public OlmAccount() throws OlmException {
+        try {
+            mNativeId = createNewAccountJni();
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_INIT_ACCOUNT_CREATION, e.getMessage());
+        }
+    }
+
+    /**
+     * Create a new account and return it to JAVA side.<br>
+     * Since a C prt is returned as a jlong, special care will be taken
+     * to make the cast (OlmAccount* to jlong) platform independent.
+     * @return the initialized OlmAccount* instance or throw an exception if fails
+     **/
+    private native long createNewAccountJni();
+
+    /**
+     * Getter on the account ID.
+     * @return native account ID
+     */
+    long getOlmAccountId(){
+        return mNativeId;
+    }
+
+    /**
+     * Release native account and invalid its JAVA reference counter part.<br>
+     * Public API for {@link #releaseAccountJni()}.
+     */
+    public void releaseAccount() {
+        if (0 != mNativeId) {
+            releaseAccountJni();
+        }
+        mNativeId = 0;
+    }
+
+    /**
+     * Destroy the corresponding OLM account native object.<br>
+     * This method must ALWAYS be called when this JAVA instance
+     * is destroyed (ie. garbage collected) to prevent memory leak in native side.
+     * See {@link #createNewAccountJni()}.
+     */
+    private native void releaseAccountJni();
+
+    /**
+     * Return true the object resources have been released.<br>
+     * @return true the object resources have been released
+     */
+    public boolean isReleased() {
+        return (0 == mNativeId);
+    }
+
+    /**
+     * Return the identity keys (identity and fingerprint keys) in a dictionary.<br>
+     * Public API for {@link #identityKeysJni()}.<br>
+     * Ex:<tt>
+     * {
+     *  "curve25519":"Vam++zZPMqDQM6ANKpO/uAl5ViJSHxV9hd+b0/fwRAg",
+     *  "ed25519":"+v8SOlOASFTMrX3MCKBM4iVnYoZ+JIjpNt1fi8Z9O2I"
+     * }</tt>
+     * @return identity keys dictionary if operation succeeds, null otherwise
+     * @exception OlmException the failure reason
+     */
+    public Map<String, String> identityKeys() throws OlmException {
+        JSONObject identityKeysJsonObj = null;
+
+        byte[] identityKeysBuffer;
+
+        try {
+            identityKeysBuffer = identityKeysJni();
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## identityKeys(): Failure - " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_IDENTITY_KEYS, e.getMessage());
+        }
+
+        if (null != identityKeysBuffer) {
+            try {
+                identityKeysJsonObj = new JSONObject(new String(identityKeysBuffer, "UTF-8"));
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## identityKeys(): Exception - Msg=" + e.getMessage());
+            }
+        } else {
+            Log.e(LOG_TAG, "## identityKeys(): Failure - identityKeysJni()=null");
+        }
+
+        return OlmUtility.toStringMap(identityKeysJsonObj);
+    }
+
+    /**
+     * Get the public identity keys (Ed25519 fingerprint key and Curve25519 identity key).<br>
+     * Keys are Base64 encoded.
+     * These keys must be published on the server.
+     * @return the identity keys or throw an exception if it fails
+     */
+    private native byte[] identityKeysJni();
+
+    /**
+     * Return the largest number of "one time keys" this account can store.
+     * @return the max number of "one time keys", -1 otherwise
+     */
+    public long maxOneTimeKeys() {
+        return maxOneTimeKeysJni();
+    }
+
+    /**
+     * Return the largest number of "one time keys" this account can store.
+     * @return the max number of "one time keys", -1 otherwise
+     */
+    private native long maxOneTimeKeysJni();
+
+    /**
+     * Generate a number of new one time keys.<br> If total number of keys stored
+     * by this account exceeds {@link #maxOneTimeKeys()}, the old keys are discarded.<br>
+     * The corresponding keys are retrieved by {@link #oneTimeKeys()}.
+     * @param aNumberOfKeys number of keys to generate
+     * @exception OlmException the failure reason
+     */
+    public void generateOneTimeKeys(int aNumberOfKeys) throws OlmException {
+        try {
+            generateOneTimeKeysJni(aNumberOfKeys);
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_GENERATE_ONE_TIME_KEYS, e.getMessage());
+        }
+    }
+
+    /**
+     * Generate a number of new one time keys.<br> If total number of keys stored
+     * by this account exceeds {@link #maxOneTimeKeys()}, the old keys are discarded.
+     * An exception is thrown if the operation fails.<br>
+     * @param aNumberOfKeys number of keys to generate
+     */
+    private native void generateOneTimeKeysJni(int aNumberOfKeys);
+
+    /**
+     * Return the "one time keys" in a dictionary.<br>
+     * The number of "one time keys", is specified by {@link #generateOneTimeKeys(int)}<br>
+     * Ex:<tt>
+     * { "curve25519":
+     *  {
+     *      "AAAABQ":"qefVZd8qvjOpsFzoKSAdfUnJVkIreyxWFlipCHjSQQg",
+     *      "AAAABA":"/X8szMU+p+lsTnr56wKjaLgjTMQQkCk8EIWEAilZtQ8",
+     *      "AAAAAw":"qxNxxFHzevFntaaPdT0fhhO7tc7pco4+xB/5VRG81hA",
+     *  }
+     * }</tt><br>
+     * Public API for {@link #oneTimeKeysJni()}.<br>
+     * Note: these keys are to be published on the server.
+     * @return one time keys in string dictionary.
+     * @exception OlmException the failure reason
+     */
+    public Map<String, Map<String, String>> oneTimeKeys() throws OlmException {
+        JSONObject oneTimeKeysJsonObj = null;
+        byte[] oneTimeKeysBuffer;
+
+        try {
+            oneTimeKeysBuffer = oneTimeKeysJni();
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_ONE_TIME_KEYS, e.getMessage());
+        }
+
+        if( null != oneTimeKeysBuffer) {
+            try {
+                oneTimeKeysJsonObj = new JSONObject(new String(oneTimeKeysBuffer, "UTF-8"));
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## oneTimeKeys(): Exception - Msg=" + e.getMessage());
+            }
+        } else {
+            Log.e(LOG_TAG, "## oneTimeKeys(): Failure - identityKeysJni()=null");
+        }
+
+        return OlmUtility.toStringMapMap(oneTimeKeysJsonObj);
+    }
+
+    /**
+     * Get the public parts of the unpublished "one time keys" for the account.<br>
+     * The returned data is a JSON-formatted object with the single property
+     * <tt>curve25519</tt>, which is itself an object mapping key id to
+     * base64-encoded Curve25519 key.<br>
+     * @return byte array containing the one time keys or throw an exception if it fails
+     */
+    private native byte[] oneTimeKeysJni();
+
+    /**
+     * Remove the "one time keys" that the session used from the account.
+     * @param aSession session instance
+     * @throws OlmException the failure reason
+     */
+    public void removeOneTimeKeys(OlmSession aSession) throws OlmException {
+        if (null != aSession) {
+            try {
+                removeOneTimeKeysJni(aSession.getOlmSessionId());
+            } catch (Exception e) {
+                throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_REMOVE_ONE_TIME_KEYS, e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Remove the "one time keys" that the session used from the account.
+     * An exception is thrown if the operation fails.
+     * @param aNativeOlmSessionId native session instance identifier
+     */
+    private native void removeOneTimeKeysJni(long aNativeOlmSessionId);
+
+    /**
+     * Marks the current set of "one time keys" as being published.
+     * @exception OlmException the failure reason
+     */
+    public void markOneTimeKeysAsPublished() throws OlmException {
+        try {
+            markOneTimeKeysAsPublishedJni();
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_MARK_ONE_KEYS_AS_PUBLISHED, e.getMessage());
+        }
+    }
+
+    /**
+     * Marks the current set of "one time keys" as being published.
+     * An exception is thrown if the operation fails.
+     */
+    private native void markOneTimeKeysAsPublishedJni();
+
+    /**
+     * Sign a message with the ed25519 fingerprint key for this account.<br>
+     * The signed message is returned by the method.
+     * @param aMessage message to sign
+     * @return the signed message
+     * @exception OlmException the failure reason
+     */
+    public String signMessage(String aMessage) throws OlmException {
+        String result = null;
+
+        if (null != aMessage) {
+            try {
+                byte[] utf8String = aMessage.getBytes("UTF-8");
+
+                if (null != utf8String) {
+                    byte[] signedMessage = signMessageJni(utf8String);
+
+                    if (null != signedMessage) {
+                        result = new String(signedMessage, "UTF-8");
+                    }
+                }
+            } catch (Exception e) {
+                throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_SIGN_MESSAGE, e.getMessage());
+            }
+        }
+
+        return result;
+    }
+
+    /**
+     * Sign a message with the ed25519 fingerprint key for this account.<br>
+     * The signed message is returned by the method.
+     * @param aMessage message to sign
+     * @return the signed message
+     */
+    private native byte[] signMessageJni(byte[] aMessage);
+
+    //==============================================================================================================
+    // Serialization management
+    //==============================================================================================================
+
+    /**
+     * Kick off the serialization mechanism.
+     * @param aOutStream output stream for serializing
+     * @throws IOException exception
+     */
+    private void writeObject(ObjectOutputStream aOutStream) throws IOException {
+        serialize(aOutStream);
+    }
+
+    /**
+     * Kick off the deserialization mechanism.
+     * @param aInStream input stream
+     * @throws Exception exception
+     */
+    private void readObject(ObjectInputStream aInStream) throws Exception {
+        deserialize(aInStream);
+    }
+
+    /**
+     * Return an account as a bytes buffer.<br>
+     * The account is serialized and encrypted with aKey.
+     * In case of failure, an error human readable
+     * description is provide in aErrorMsg.
+     * @param aKey encryption key
+     * @param aErrorMsg error message description
+     * @return the account as bytes buffer
+     */
+    @Override
+    protected byte[] serialize(byte[] aKey, StringBuffer aErrorMsg) {
+        byte[] pickleRetValue = null;
+
+        // sanity check
+        if(null == aErrorMsg) {
+            Log.e(LOG_TAG,"## serialize(): invalid parameter - aErrorMsg=null");
+        } else if (null ==  aKey) {
+            aErrorMsg.append("Invalid input parameters in serializeDataWithKey()");
+        } else {
+            aErrorMsg.setLength(0);
+            try {
+                pickleRetValue = serializeJni(aKey);
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## serialize() failed " + e.getMessage());
+                aErrorMsg.append(e.getMessage());
+            }
+        }
+
+        return pickleRetValue;
+    }
+
+    /**
+     * Serialize and encrypt account instance.<br>
+     * @param aKeyBuffer key used to encrypt the serialized account data
+     * @return the serialised account as bytes buffer.
+     **/
+    private native byte[] serializeJni(byte[] aKeyBuffer);
+
+    /**
+     * Loads an account from a pickled bytes buffer.<br>
+     * See {@link #serialize(byte[], StringBuffer)}
+     * @param aSerializedData bytes buffer
+     * @param aKey key used to encrypted
+     * @exception Exception the exception
+     */
+    @Override
+    protected void deserialize(byte[] aSerializedData, byte[] aKey) throws Exception {
+        String errorMsg = null;
+
+        try {
+            if ((null == aSerializedData) || (null == aKey)) {
+                Log.e(LOG_TAG, "## deserialize(): invalid input parameters");
+                errorMsg = "invalid input parameters";
+            } else {
+                mNativeId = deserializeJni(aSerializedData, aKey);
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## deserialize() failed " + e.getMessage());
+            errorMsg = e.getMessage();
+        }
+
+        if (!TextUtils.isEmpty(errorMsg)) {
+            releaseAccount();
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_DESERIALIZATION, errorMsg);
+        }
+    }
+
+    /**
+     * Allocate a new account and initialize it with the serialisation data.<br>
+     * @param aSerializedDataBuffer the account serialisation buffer
+     * @param aKeyBuffer the key used to encrypt the serialized account data
+     * @return the deserialized account
+     **/
+    private native long deserializeJni(byte[] aSerializedDataBuffer, byte[] aKeyBuffer);
+}
diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmException.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmException.java
new file mode 100644
index 0000000..b0b1a6a
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmException.java
@@ -0,0 +1,85 @@
+/*
+ * Copyright 2017 OpenMarket Ltd
+ * Copyright 2017 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.olm;
+
+import java.io.IOException;
+
+/**
+ * Exception class to identify specific Olm SDK exceptions.
+ */
+public class OlmException extends IOException {
+    // exception codes
+
+    public static final int EXCEPTION_CODE_INIT_ACCOUNT_CREATION = 10;
+
+    public static final int EXCEPTION_CODE_ACCOUNT_SERIALIZATION = 100;
+    public static final int EXCEPTION_CODE_ACCOUNT_DESERIALIZATION = 101;
+    public static final int EXCEPTION_CODE_ACCOUNT_IDENTITY_KEYS = 102;
+    public static final int EXCEPTION_CODE_ACCOUNT_GENERATE_ONE_TIME_KEYS = 103;
+    public static final int EXCEPTION_CODE_ACCOUNT_ONE_TIME_KEYS = 104;
+    public static final int EXCEPTION_CODE_ACCOUNT_REMOVE_ONE_TIME_KEYS = 105;
+    public static final int EXCEPTION_CODE_ACCOUNT_MARK_ONE_KEYS_AS_PUBLISHED = 106;
+    public static final int EXCEPTION_CODE_ACCOUNT_SIGN_MESSAGE = 107;
+
+    public static final int EXCEPTION_CODE_CREATE_INBOUND_GROUP_SESSION = 200;
+    public static final int EXCEPTION_CODE_INIT_INBOUND_GROUP_SESSION = 201;
+    public static final int EXCEPTION_CODE_INBOUND_GROUP_SESSION_IDENTIFIER = 202;
+    public static final int EXCEPTION_CODE_INBOUND_GROUP_SESSION_DECRYPT_SESSION = 203;
+
+    public static final int EXCEPTION_CODE_CREATE_OUTBOUND_GROUP_SESSION = 300;
+    public static final int EXCEPTION_CODE_INIT_OUTBOUND_GROUP_SESSION = 301;
+    public static final int EXCEPTION_CODE_OUTBOUND_GROUP_SESSION_IDENTIFIER = 302;
+    public static final int EXCEPTION_CODE_OUTBOUND_GROUP_SESSION_KEY = 303;
+    public static final int EXCEPTION_CODE_OUTBOUND_GROUP_ENCRYPT_MESSAGE = 304;
+
+    public static final int EXCEPTION_CODE_INIT_SESSION_CREATION = 400;
+    public static final int EXCEPTION_CODE_SESSION_INIT_OUTBOUND_SESSION = 401;
+    public static final int EXCEPTION_CODE_SESSION_INIT_INBOUND_SESSION = 402;
+    public static final int EXCEPTION_CODE_SESSION_INIT_INBOUND_SESSION_FROM = 403;
+    public static final int EXCEPTION_CODE_SESSION_ENCRYPT_MESSAGE = 404;
+    public static final int EXCEPTION_CODE_SESSION_DECRYPT_MESSAGE = 405;
+    public static final int EXCEPTION_CODE_SESSION_SESSION_IDENTIFIER = 406;
+
+    public static final int EXCEPTION_CODE_UTILITY_CREATION = 500;
+    public static final int EXCEPTION_CODE_UTILITY_VERIFY_SIGNATURE = 501;
+
+    // exception human readable messages
+    public static final String EXCEPTION_MSG_INVALID_PARAMS_DESERIALIZATION = "invalid de-serialized parameters";
+
+    /** exception code to be taken from: {@link #EXCEPTION_CODE_CREATE_OUTBOUND_GROUP_SESSION}, {@link #EXCEPTION_CODE_CREATE_INBOUND_GROUP_SESSION},
+     * {@link #EXCEPTION_CODE_INIT_OUTBOUND_GROUP_SESSION}, {@link #EXCEPTION_CODE_INIT_INBOUND_GROUP_SESSION}..**/
+    private final int mCode;
+
+    /** Human readable message description **/
+    private final String mMessage;
+
+    public OlmException(int aExceptionCode, String aExceptionMessage) {
+        super();
+        mCode = aExceptionCode;
+        mMessage = aExceptionMessage;
+    }
+
+    public int getExceptionCode() {
+        return mCode;
+    }
+
+    @Override
+    public String getMessage() {
+        return mMessage;
+    }
+}
diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmInboundGroupSession.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmInboundGroupSession.java
new file mode 100644
index 0000000..571bddb
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmInboundGroupSession.java
@@ -0,0 +1,260 @@
+/*
+ * Copyright 2017 OpenMarket Ltd
+ * Copyright 2017 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.olm;
+
+import android.text.TextUtils;
+import android.util.Log;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+
+/**
+ * Class used to create an inbound <a href="http://matrix.org/docs/guides/e2e_implementation.html#handling-an-m-room-key-event">Megolm session</a>.<br>
+ * Counter part of the outbound group session {@link OlmOutboundGroupSession}, this class decrypts the messages sent by the outbound side.
+ *
+ * <br><br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmInboundGroupSession extends CommonSerializeUtils implements Serializable {
+    private static final long serialVersionUID = -772028491251653253L;
+    private static final String LOG_TAG = "OlmInboundGroupSession";
+
+    /** Session Id returned by JNI.<br>
+     * This value uniquely identifies the native inbound group session instance.
+     */
+    private transient long mNativeId;
+
+    /**
+     * Result in {@link #decryptMessage(String)}
+     */
+    public static class DecryptMessageResult {
+        /** decrypt message **/
+        public String mDecryptedMessage;
+
+        /** decrypt index **/
+        public long mIndex;
+    }
+
+    /**
+     * Constructor.<br>
+     * Create and save a new native session instance ID and start a new inbound group session.
+     * The session key parameter is retrieved from an outbound group session.
+     * @param aSessionKey session key
+     * @throws OlmException constructor failure
+     */
+    public OlmInboundGroupSession(String aSessionKey) throws OlmException {
+        if (TextUtils.isEmpty(aSessionKey)) {
+            Log.e(LOG_TAG, "## initInboundGroupSession(): invalid session key");
+            throw new OlmException(OlmException.EXCEPTION_CODE_INIT_INBOUND_GROUP_SESSION, "invalid session key");
+        } else {
+            try {
+                mNativeId = createNewSessionJni(aSessionKey.getBytes("UTF-8"));
+            } catch (Exception e) {
+                throw new OlmException(OlmException.EXCEPTION_CODE_INIT_INBOUND_GROUP_SESSION, e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Initialize a new inbound group session and return it to JAVA side.<br>
+     * Since a C prt is returned as a jlong, special care will be taken
+     * to make the cast (OlmInboundGroupSession* to jlong) platform independent.
+     * @param aSessionKeyBuffer session key from an outbound session
+     * @return the initialized OlmInboundGroupSession* instance or throw an exception it fails.
+     **/
+    private native long createNewSessionJni(byte[] aSessionKeyBuffer);
+
+    /**
+     * Release native session and invalid its JAVA reference counter part.<br>
+     * Public API for {@link #releaseSessionJni()}.
+     */
+    public void releaseSession(){
+        if (0 != mNativeId) {
+            releaseSessionJni();
+        }
+        mNativeId = 0;
+    }
+
+    /**
+     * Destroy the corresponding OLM inbound group session native object.<br>
+     * This method must ALWAYS be called when this JAVA instance
+     * is destroyed (ie. garbage collected) to prevent memory leak in native side.
+     * See {@link #createNewSessionJni(byte[])}.
+     */
+    private native void releaseSessionJni();
+
+    /**
+     * Return true the object resources have been released.<br>
+     * @return true the object resources have been released
+     */
+    public boolean isReleased() {
+        return (0 == mNativeId);
+    }
+
+    /**
+     * Retrieve the base64-encoded identifier for this inbound group session.
+     * @return the session ID
+     * @throws OlmException the failure reason
+     */
+    public String sessionIdentifier() throws OlmException {
+        try {
+            return new String(sessionIdentifierJni(), "UTF-8");
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## sessionIdentifier() failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_INBOUND_GROUP_SESSION_IDENTIFIER, e.getMessage());
+        }
+    }
+
+    /**
+     * Get a base64-encoded identifier for this inbound group session.
+     * An exception is thrown if the operation fails.
+     * @return the base64-encoded identifier
+     */
+    private native byte[] sessionIdentifierJni();
+
+    /**
+     * Decrypt the message passed in parameter.<br>
+     * In case of error, null is returned and an error message description is provided in aErrorMsg.
+     * @param aEncryptedMsg the message to be decrypted
+     * @return the decrypted message information
+     * @exception OlmException teh failure reason
+     */
+    public DecryptMessageResult decryptMessage(String aEncryptedMsg) throws OlmException {
+        DecryptMessageResult result = new DecryptMessageResult();
+
+        try {
+            byte[] decryptedMessageBuffer = decryptMessageJni(aEncryptedMsg.getBytes("UTF-8"), result);
+
+            if (null != decryptedMessageBuffer) {
+                result.mDecryptedMessage = new String(decryptedMessageBuffer, "UTF-8");
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## decryptMessage() failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_INBOUND_GROUP_SESSION_DECRYPT_SESSION, e.getMessage());
+        }
+
+        return result;
+    }
+
+    /**
+     * Decrypt a message.
+     * An exception is thrown if the operation fails.
+     * @param aEncryptedMsg the encrypted message
+     * @param aDecryptMessageResult the decryptMessage informaton
+     * @return the decrypted message
+     */
+    private native byte[] decryptMessageJni(byte[] aEncryptedMsg, DecryptMessageResult aDecryptMessageResult);
+
+    //==============================================================================================================
+    // Serialization management
+    //==============================================================================================================
+
+    /**
+     * Kick off the serialization mechanism.
+     * @param aOutStream output stream for serializing
+     * @throws IOException exception
+     */
+    private void writeObject(ObjectOutputStream aOutStream) throws IOException {
+        serialize(aOutStream);
+    }
+
+    /**
+     * Kick off the deserialization mechanism.
+     * @param aInStream input stream
+     * @throws Exception exception
+     */
+    private void readObject(ObjectInputStream aInStream) throws Exception {
+        deserialize(aInStream);
+    }
+
+    /**
+     * Return the current inbound group session as a bytes buffer.<br>
+     * The session is serialized and encrypted with aKey.
+     * In case of failure, an error human readable
+     * description is provide in aErrorMsg.
+     * @param aKey encryption key
+     * @param aErrorMsg error message description
+     * @return pickled bytes buffer if operation succeed, null otherwise
+     */
+    @Override
+    protected byte[] serialize(byte[] aKey, StringBuffer aErrorMsg) {
+        byte[] pickleRetValue = null;
+
+        // sanity check
+        if(null == aErrorMsg) {
+            Log.e(LOG_TAG,"## serialize(): invalid parameter - aErrorMsg=null");
+            aErrorMsg.append("aErrorMsg=null");
+        } else if (null == aKey) {
+            aErrorMsg.append("Invalid input parameters in serialize()");
+        } else {
+            aErrorMsg.setLength(0);
+            try {
+                pickleRetValue = serializeJni(aKey);
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## serialize() failed " + e.getMessage());
+                aErrorMsg.append(e.getMessage());
+            }
+        }
+
+        return pickleRetValue;
+    }
+    /**
+     * JNI counter part of {@link #serialize(byte[], StringBuffer)}.
+     * @param aKey encryption key
+     * @return the serialized session
+     */
+    private native byte[] serializeJni(byte[] aKey);
+
+    /**
+     * Loads an account from a pickled base64 string.<br>
+     * See {@link #serialize(byte[], StringBuffer)}
+     * @param aSerializedData pickled account in a bytes buffer
+     * @param aKey key used to encrypted
+     */
+    @Override
+    protected void deserialize(byte[] aSerializedData, byte[] aKey) throws Exception {
+        String errorMsg = null;
+
+        try {
+            if ((null == aSerializedData) || (null == aKey)) {
+                Log.e(LOG_TAG, "## deserialize(): invalid input parameters");
+                errorMsg = "invalid input parameters";
+            } else {
+                mNativeId = deserializeJni(aSerializedData, aKey);
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## deserialize() failed " + e.getMessage());
+            errorMsg = e.getMessage();
+        }
+
+        if (!TextUtils.isEmpty(errorMsg)) {
+            releaseSession();
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_DESERIALIZATION, errorMsg);
+        }
+    }
+
+    /**
+     * Allocate a new session and initialize it with the serialisation data.<br>
+     * An exception is thrown if the operation fails.
+     * @param aSerializedData the session serialisation buffer
+     * @param aKey the key used to encrypt the serialized account data
+     * @return the deserialized session
+     **/
+    private native long deserializeJni(byte[] aSerializedData, byte[] aKey);
+}
diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmManager.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmManager.java
new file mode 100644
index 0000000..c1e6031
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmManager.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.olm;
+
+import android.content.Context;
+import android.util.Log;
+
+/**
+ * Olm SDK entry point class.<br> An OlmManager instance must be created at first to enable native library load.
+ * <br><br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmManager {
+    private static final String LOG_TAG = "OlmManager";
+
+    /**
+     * Constructor.
+     */
+    public OlmManager() {
+    }
+
+    static {
+        try {
+            java.lang.System.loadLibrary("olm");
+        } catch(UnsatisfiedLinkError e) {
+            Log.e(LOG_TAG,"Exception loadLibrary() - Msg="+e.getMessage());
+        }
+    }
+
+    /**
+     * Provide the android library version
+     * @param context the context
+     * @return the library version
+     */
+    public String getSdkOlmVersion(Context context) {
+        String gitVersion = context.getResources().getString(R.string.git_olm_revision);
+        String date = context.getResources().getString(R.string.git_olm_revision_date);
+        return gitVersion + "-" + date;
+    }
+
+    /**
+     * Get the OLM lib version.
+     * @return the lib version as a string
+     */
+    public String getOlmLibVersion(){
+        return getOlmLibVersionJni();
+    }
+    public native String getOlmLibVersionJni();
+}
+
diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmMessage.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmMessage.java
new file mode 100644
index 0000000..08db993
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmMessage.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.olm;
+
+/**
+ * Message class used in Olm sessions to contain the encrypted data.<br>
+ * See {@link OlmSession#decryptMessage(OlmMessage)} and {@link OlmSession#encryptMessage(String)}.
+ * <br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmMessage {
+    /** PRE KEY message type (used to establish new Olm session) **/
+    public final static int MESSAGE_TYPE_PRE_KEY = 0;
+    /** normal message type **/
+    public final static int MESSAGE_TYPE_MESSAGE = 1;
+
+    /** the encrypted message **/
+    public String mCipherText;
+
+    /** defined by {@link #MESSAGE_TYPE_MESSAGE} or {@link #MESSAGE_TYPE_PRE_KEY}**/
+    public long mType;
+}
diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmOutboundGroupSession.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmOutboundGroupSession.java
new file mode 100644
index 0000000..0481824
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmOutboundGroupSession.java
@@ -0,0 +1,289 @@
+/*
+ * Copyright 2017 OpenMarket Ltd
+ * Copyright 2017 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.olm;
+
+
+import android.text.TextUtils;
+import android.util.Log;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+
+/**
+ * Class used to create an outbound a <a href="http://matrix.org/docs/guides/e2e_implementation.html#starting-a-megolm-session">Megolm session</a>.<br>
+ * To send a first message in an encrypted room, the client should start a new outbound Megolm session.
+ * The session ID and the session key must be shared with each device in the room within.
+ *
+ * <br><br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmOutboundGroupSession extends CommonSerializeUtils implements Serializable {
+    private static final long serialVersionUID = -3133097431283604416L;
+    private static final String LOG_TAG = "OlmOutboundGroupSession";
+
+    /** Session Id returned by JNI.<br>
+     * This value uniquely identifies the native outbound group session instance.
+     */
+    private transient long mNativeId;
+
+    /**
+     * Constructor.<br>
+     * Create and save a new session native instance ID and
+     * initialise a new outbound group session.<br>
+     * @throws OlmException constructor failure
+     */
+    public OlmOutboundGroupSession() throws OlmException {
+        try {
+            mNativeId = createNewSessionJni();
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_CREATE_OUTBOUND_GROUP_SESSION, e.getMessage());
+        }
+    }
+
+    /**
+     * Create the corresponding OLM outbound group session in native side.<br>
+     * An exception is thrown if the operation fails.
+     * Do not forget to call {@link #releaseSession()} when JAVA side is done.
+     * @return native session instance identifier (see {@link #mNativeId})
+     */
+    private native long createNewSessionJni();
+
+    /**
+     * Release native session and invalid its JAVA reference counter part.<br>
+     * Public API for {@link #releaseSessionJni()}.
+     */
+    public void releaseSession() {
+        if (0 != mNativeId) {
+            releaseSessionJni();
+        }
+        mNativeId = 0;
+    }
+
+    /**
+     * Destroy the corresponding OLM outbound group session native object.<br>
+     * This method must ALWAYS be called when this JAVA instance
+     * is destroyed (ie. garbage collected) to prevent memory leak in native side.
+     * See {@link #createNewSessionJni()}.
+     */
+    private native void releaseSessionJni();
+
+    /**
+     * Return true the object resources have been released.<br>
+     * @return true the object resources have been released
+     */
+    public boolean isReleased() {
+        return (0 == mNativeId);
+    }
+
+    /**
+     * Get a base64-encoded identifier for this session.
+     * @return session identifier
+     * @throws OlmException the failure reason
+     */
+    public String sessionIdentifier() throws OlmException {
+        try {
+            return new String(sessionIdentifierJni(), "UTF-8");
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## sessionIdentifier() failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_OUTBOUND_GROUP_SESSION_IDENTIFIER, e.getMessage());
+        }
+    }
+
+    /**
+     * Return the session identifier.
+     * An exception is thrown if the operation fails.
+     * @return the session identifier
+     */
+    private native byte[] sessionIdentifierJni();
+
+    /**
+     * Get the current message index for this session.<br>
+     * Each message is sent with an increasing index, this
+     * method returns the index for the next message.
+     * @return current session index
+     */
+    public int messageIndex() {
+        return messageIndexJni();
+    }
+
+    /**
+     * Get the current message index for this session.<br>
+     * Each message is sent with an increasing index, this
+     * method returns the index for the next message.
+     * An exception is thrown if the operation fails.
+     * @return current session index
+     */
+    private native int messageIndexJni();
+
+    /**
+     * Get the base64-encoded current ratchet key for this session.<br>
+     * Each message is sent with a different ratchet key. This method returns the
+     * ratchet key that will be used for the next message.
+     * @return outbound session key
+     * @exception OlmException the failure reason
+     */
+    public String sessionKey() throws OlmException {
+        try {
+            return new String(sessionKeyJni(), "UTF-8");
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## sessionKey() failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_OUTBOUND_GROUP_SESSION_KEY, e.getMessage());
+        }
+    }
+
+    /**
+     * Return the session key.
+     * An exception is thrown if the operation fails.
+     * @return the session key
+     */
+    private native byte[] sessionKeyJni();
+
+    /**
+     * Encrypt some plain-text message.<br>
+     * The message given as parameter is encrypted and returned as the return value.
+     * @param aClearMsg message to be encrypted
+     * @return the encrypted message
+     * @exception OlmException the encryption failure reason
+     */
+    public String encryptMessage(String aClearMsg) throws OlmException {
+        String retValue = null;
+
+        if (!TextUtils.isEmpty(aClearMsg)) {
+            try {
+                byte[] encryptedBuffer = encryptMessageJni(aClearMsg.getBytes("UTF-8"));
+
+                if (null != encryptedBuffer) {
+                    retValue = new String(encryptedBuffer , "UTF-8");
+                }
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## encryptMessage() failed " + e.getMessage());
+                throw new OlmException(OlmException.EXCEPTION_CODE_OUTBOUND_GROUP_ENCRYPT_MESSAGE, e.getMessage());
+            }
+        }
+
+        return retValue;
+    }
+
+    /**
+     * Encrypt a bytes buffer messages.
+     * An exception is thrown if the operation fails.
+     * @param aClearMsgBuffer  the message to encode
+     * @return the encoded message
+     */
+    private native byte[] encryptMessageJni(byte[] aClearMsgBuffer);
+
+    //==============================================================================================================
+    // Serialization management
+    //==============================================================================================================
+
+    /**
+     * Kick off the serialization mechanism.
+     * @param aOutStream output stream for serializing
+     * @throws IOException exception
+     */
+    private void writeObject(ObjectOutputStream aOutStream) throws IOException {
+        serialize(aOutStream);
+    }
+
+    /**
+     * Kick off the deserialization mechanism.
+     * @param aInStream input stream
+     * @throws Exception exception
+     */
+    private void readObject(ObjectInputStream aInStream) throws Exception {
+        deserialize(aInStream);
+    }
+
+    /**
+     * Return the current outbound group session as a base64 byte buffers.<br>
+     * The session is serialized and encrypted with aKey.
+     * In case of failure, an error human readable
+     * description is provide in aErrorMsg.
+     * @param aKey encryption key
+     * @param aErrorMsg error message description
+     * @return pickled base64 bytes buffer if operation succeed, null otherwise
+     */
+    @Override
+    protected byte[] serialize(byte[] aKey, StringBuffer aErrorMsg) {
+        byte[] pickleRetValue = null;
+
+        // sanity check
+        if(null == aErrorMsg) {
+            Log.e(LOG_TAG,"## serialize(): invalid parameter - aErrorMsg=null");
+        } else if (null == aKey) {
+            aErrorMsg.append("Invalid input parameters in serialize()");
+        } else {
+            try {
+                pickleRetValue = serializeJni(aKey);
+            } catch (Exception e) {
+                Log.e(LOG_TAG,"## serialize(): failed " + e.getMessage());
+                aErrorMsg.append(e.getMessage());
+            }
+        }
+
+        return pickleRetValue;
+    }
+
+    /**
+     * JNI counter part of {@link #serialize(byte[], StringBuffer)}.
+     * An exception is thrown if the operation fails.
+     * @param aKey encryption key
+     * @return the serialized session
+     */
+    private native byte[] serializeJni(byte[] aKey);
+
+    /**
+     * Loads an account from a pickled base64 string.<br>
+     * See {@link #serialize(byte[], StringBuffer)}
+     * @param aSerializedData pickled account in a base64 bytes buffer
+     * @param aKey key used to encrypted
+     * @exception Exception the exception
+     */
+    @Override
+    protected void deserialize(byte[] aSerializedData, byte[] aKey) throws Exception {
+        String errorMsg = null;
+
+        try {
+            if ((null == aSerializedData) || (null == aKey)) {
+                Log.e(LOG_TAG, "## deserialize(): invalid input parameters");
+                errorMsg = "invalid input parameters";
+            } else {
+                mNativeId = deserializeJni(aSerializedData, aKey);
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## deserialize() failed " + e.getMessage());
+            errorMsg = e.getMessage();
+        }
+
+        if (!TextUtils.isEmpty(errorMsg)) {
+            releaseSession();
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_DESERIALIZATION, errorMsg);
+        }
+    }
+
+    /**
+     * Allocate a new session and initialize it with the serialisation data.<br>
+     * An exception is thrown if the operation fails.
+     * @param aSerializedData the session serialisation buffer
+     * @param aKey the key used to encrypt the serialized account data
+     * @return the deserialized session
+     **/
+    private native long deserializeJni(byte[] aSerializedData, byte[] aKey);
+
+}
diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmSession.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmSession.java
new file mode 100644
index 0000000..da2e963
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmSession.java
@@ -0,0 +1,445 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.olm;
+
+import android.text.TextUtils;
+import android.util.Log;
+
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+
+/**
+ * Session class used to create Olm sessions in conjunction with {@link OlmAccount} class.<br>
+ * Olm session is used to encrypt data between devices, especially to create Olm group sessions (see {@link OlmOutboundGroupSession} and {@link OlmInboundGroupSession}).<br>
+ * To establish an Olm session with Bob, Alice calls {@link #initOutboundSession(OlmAccount, String, String)} with Bob's identity and onetime keys. Then Alice generates an encrypted PRE_KEY message ({@link #encryptMessage(String)})
+ * used by Bob to open the Olm session in his side with {@link #initOutboundSession(OlmAccount, String, String)}.
+ * From this step on, messages can be exchanged by using {@link #encryptMessage(String)} and {@link #decryptMessage(OlmMessage)}.
+ * <br><br>Detailed implementation guide is available at <a href="http://matrix.org/docs/guides/e2e_implementation.html">Implementing End-to-End Encryption in Matrix clients</a>.
+ */
+public class OlmSession extends CommonSerializeUtils implements Serializable {
+    private static final long serialVersionUID = -8975488639186976419L;
+    private static final String LOG_TAG = "OlmSession";
+
+    /** Session Id returned by JNI.
+     * This value uniquely identifies the native session instance.
+     **/
+    private transient long mNativeId;
+
+    public OlmSession() throws OlmException {
+        try {
+            mNativeId = createNewSessionJni();
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_INIT_SESSION_CREATION, e.getMessage());
+        }
+    }
+
+    /**
+     * Create an OLM session in native side.<br>
+     * Do not forget to call {@link #releaseSession()} when JAVA side is done.
+     * @return native account instance identifier or throw an exception.
+     */
+    private native long createNewSessionJni();
+
+    /**
+     * Getter on the session ID.
+     * @return native session ID
+     */
+    long getOlmSessionId(){
+        return mNativeId;
+    }
+
+    /**
+     * Destroy the corresponding OLM session native object.<br>
+     * This method must ALWAYS be called when this JAVA instance
+     * is destroyed (ie. garbage collected) to prevent memory leak in native side.
+     * See {@link #createNewSessionJni()}.
+     */
+    private native void releaseSessionJni();
+
+    /**
+     * Release native session and invalid its JAVA reference counter part.<br>
+     * Public API for {@link #releaseSessionJni()}.
+     */
+    public void releaseSession() {
+        if (0 != mNativeId) {
+            releaseSessionJni();
+        }
+        mNativeId = 0;
+    }
+
+    /**
+     * Return true the object resources have been released.<br>
+     * @return true the object resources have been released
+     */
+    public boolean isReleased() {
+        return (0 == mNativeId);
+    }
+
+    /**
+     * Creates a new out-bound session for sending messages to a recipient
+     * identified by an identity key and a one time key.<br>
+     * @param aAccount the account to associate with this session
+     * @param aTheirIdentityKey the identity key of the recipient
+     * @param aTheirOneTimeKey the one time key of the recipient
+     * @exception OlmException the failure reason
+     */
+    public void initOutboundSession(OlmAccount aAccount, String aTheirIdentityKey, String aTheirOneTimeKey) throws OlmException {
+        if ((null == aAccount) || TextUtils.isEmpty(aTheirIdentityKey) || TextUtils.isEmpty(aTheirOneTimeKey)) {
+            Log.e(LOG_TAG, "## initOutboundSession(): invalid input parameters");
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_OUTBOUND_SESSION, "invalid input parameters");
+        } else {
+            try {
+                initOutboundSessionJni(aAccount.getOlmAccountId(), aTheirIdentityKey.getBytes("UTF-8"), aTheirOneTimeKey.getBytes("UTF-8"));
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## initOutboundSession(): " + e.getMessage());
+                throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_OUTBOUND_SESSION, e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Create a new in-bound session for sending/receiving messages from an
+     * incoming PRE_KEY message.<br> The recipient is defined as the entity
+     * with whom the session is established.
+     * An exception is thrown if the operation fails.
+     * @param aOlmAccountId account instance
+     * @param aTheirIdentityKey the identity key of the recipient
+     * @param aTheirOneTimeKey the one time key of the recipient
+     **/
+    private native void initOutboundSessionJni(long aOlmAccountId, byte[] aTheirIdentityKey, byte[] aTheirOneTimeKey);
+
+    /**
+     * Create a new in-bound session for sending/receiving messages from an
+     * incoming PRE_KEY message ({@link OlmMessage#MESSAGE_TYPE_PRE_KEY}).<br>
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * @param aAccount the account to associate with this session
+     * @param aPreKeyMsg PRE KEY message
+     * @exception OlmException the failure reason
+     */
+    public void initInboundSession(OlmAccount aAccount, String aPreKeyMsg) throws OlmException {
+        if ((null == aAccount) || TextUtils.isEmpty(aPreKeyMsg)){
+            Log.e(LOG_TAG, "## initInboundSession(): invalid input parameters");
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_INBOUND_SESSION, "invalid input parameters");
+        } else {
+            try {
+                initInboundSessionJni(aAccount.getOlmAccountId(), aPreKeyMsg.getBytes("UTF-8"));
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## initInboundSession(): " + e.getMessage());
+                throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_INBOUND_SESSION, e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Create a new in-bound session for sending/receiving messages from an
+     * incoming PRE_KEY message.<br>
+     * An exception is thrown if the operation fails.
+     * @param aOlmAccountId account instance
+     * @param aOneTimeKeyMsg PRE_KEY message
+     */
+    private native void initInboundSessionJni(long aOlmAccountId, byte[] aOneTimeKeyMsg);
+
+    /**
+     * Create a new in-bound session for sending/receiving messages from an
+     * incoming PRE_KEY({@link OlmMessage#MESSAGE_TYPE_PRE_KEY}) message based on the sender identity key.<br>
+     * Public API for {@link #initInboundSessionFromIdKeyJni(long, byte[], byte[])}.
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * This method must only be called the first time a pre-key message is received from an inbound session.
+     * @param aAccount the account to associate with this session
+     * @param aTheirIdentityKey the sender identity key
+     * @param aPreKeyMsg PRE KEY message
+     * @exception OlmException the failure reason
+     */
+    public void initInboundSessionFrom(OlmAccount aAccount, String aTheirIdentityKey, String aPreKeyMsg) throws OlmException {
+        if ( (null==aAccount) || TextUtils.isEmpty(aPreKeyMsg)){
+            Log.e(LOG_TAG, "## initInboundSessionFrom(): invalid input parameters");
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_INBOUND_SESSION_FROM, "invalid input parameters");
+        } else {
+            try {
+                initInboundSessionFromIdKeyJni(aAccount.getOlmAccountId(), aTheirIdentityKey.getBytes("UTF-8"), aPreKeyMsg.getBytes("UTF-8"));
+            } catch (Exception e) {
+                Log.e(LOG_TAG, "## initInboundSessionFrom(): " + e.getMessage());
+                throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_INIT_INBOUND_SESSION_FROM, e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Create a new in-bound session for sending/receiving messages from an
+     * incoming PRE_KEY message based on the recipient identity key.<br>
+     * An exception is thrown if the operation fails.
+     * @param aOlmAccountId account instance
+     * @param aTheirIdentityKey the identity key of the recipient
+     * @param aOneTimeKeyMsg encrypted message
+     */
+    private native void initInboundSessionFromIdKeyJni(long aOlmAccountId, byte[] aTheirIdentityKey, byte[] aOneTimeKeyMsg);
+
+    /**
+     * Get the session identifier.<br> Will be the same for both ends of the
+     * conversation. The session identifier is returned as a String object.
+     * Session Id sample: "session_id":"M4fOVwD6AABrkTKl"
+     * Public API for {@link #getSessionIdentifierJni()}.
+     * @return the session ID
+     * @exception OlmException the failure reason
+     */
+    public String sessionIdentifier() throws OlmException {
+        try {
+            byte[] buffer = getSessionIdentifierJni();
+
+            if (null != buffer) {
+                return new String(buffer, "UTF-8");
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## sessionIdentifier(): " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_SESSION_IDENTIFIER, e.getMessage());
+        }
+
+        return null;
+    }
+
+    /**
+     * Get the session identifier for this session.
+     * An exception is thrown if the operation fails.
+     * @return the session identifier
+     */
+    private native byte[] getSessionIdentifierJni();
+
+    /**
+     * Checks if the PRE_KEY({@link OlmMessage#MESSAGE_TYPE_PRE_KEY}) message is for this in-bound session.<br>
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * Public API for {@link #matchesInboundSessionJni(byte[])}.
+     * @param aOneTimeKeyMsg PRE KEY message
+     * @return true if the one time key matches.
+     */
+    public boolean matchesInboundSession(String aOneTimeKeyMsg) {
+        boolean retCode = false;
+
+        try {
+            retCode = matchesInboundSessionJni(aOneTimeKeyMsg.getBytes("UTF-8"));
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## matchesInboundSession(): failed " + e.getMessage());
+        }
+
+        return retCode;
+    }
+
+    /**
+     * Checks if the PRE_KEY message is for this in-bound session.<br>
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * An exception is thrown if the operation fails.
+     * @param aOneTimeKeyMsg PRE KEY message
+     * @return true if the PRE_KEY message matches
+     */
+    private native boolean matchesInboundSessionJni(byte[] aOneTimeKeyMsg);
+
+    /**
+     * Checks if the PRE_KEY({@link OlmMessage#MESSAGE_TYPE_PRE_KEY}) message is for this in-bound session based on the sender identity key.<br>
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * Public API for {@link #matchesInboundSessionJni(byte[])}.
+     * @param aTheirIdentityKey the sender identity key
+     * @param aOneTimeKeyMsg PRE KEY message
+     * @return this if operation succeed, null otherwise
+     */
+    public boolean matchesInboundSessionFrom(String aTheirIdentityKey, String aOneTimeKeyMsg) {
+        boolean retCode = false;
+
+        try {
+            retCode = matchesInboundSessionFromIdKeyJni(aTheirIdentityKey.getBytes("UTF-8"), aOneTimeKeyMsg.getBytes("UTF-8"));
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## matchesInboundSessionFrom(): failed " + e.getMessage());
+        }
+
+        return retCode;
+    }
+
+    /**
+     * Checks if the PRE_KEY message is for this in-bound session based on the sender identity key.<br>
+     * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+     * An exception is thrown if the operation fails.
+     * @param aTheirIdentityKey the identity key of the sender
+     * @param aOneTimeKeyMsg PRE KEY message
+     * @return true if the PRE_KEY message matches.
+     */
+    private native boolean matchesInboundSessionFromIdKeyJni(byte[] aTheirIdentityKey, byte[] aOneTimeKeyMsg);
+
+    /**
+     * Encrypt a message using the session.<br>
+     * The encrypted message is returned in a OlmMessage object.
+     * Public API for {@link #encryptMessageJni(byte[], OlmMessage)}.
+     * @param aClearMsg message to encrypted
+     * @return the encrypted message
+     * @exception OlmException the failure reason
+     */
+    public OlmMessage encryptMessage(String aClearMsg) throws OlmException {
+        if (null == aClearMsg) {
+            return null;
+        }
+
+        OlmMessage encryptedMsgRetValue = new OlmMessage();
+
+        try {
+            byte[] encryptedMessageBuffer = encryptMessageJni(aClearMsg.getBytes("UTF-8"), encryptedMsgRetValue);
+
+            if (null != encryptedMessageBuffer) {
+                encryptedMsgRetValue.mCipherText = new String(encryptedMessageBuffer, "UTF-8");
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## encryptMessage(): failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_ENCRYPT_MESSAGE, e.getMessage());
+        }
+
+        return encryptedMsgRetValue;
+    }
+
+    /**
+     * Encrypt a message using the session.<br>
+     * An exception is thrown if the operation fails.
+     * @param aClearMsg clear text message
+     * @param aEncryptedMsg ciphered message
+     * @return the encrypted message
+     */
+    private native byte[] encryptMessageJni(byte[] aClearMsg, OlmMessage aEncryptedMsg);
+
+    /**
+     * Decrypt a message using the session.<br>
+     * The encrypted message is given as a OlmMessage object.
+     * @param aEncryptedMsg message to decrypt
+     * @return the decrypted message
+     * @exception OlmException the failure reason
+     */
+    public String decryptMessage(OlmMessage aEncryptedMsg) throws OlmException {
+        if (null == aEncryptedMsg) {
+            return null;
+        }
+
+        try {
+            return new String(decryptMessageJni(aEncryptedMsg), "UTF-8");
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## decryptMessage(): failed " + e.getMessage());
+            throw new OlmException(OlmException.EXCEPTION_CODE_SESSION_DECRYPT_MESSAGE, e.getMessage());
+        }
+    }
+    /**
+     * Decrypt a message using the session.<br>
+     * An exception is thrown if the operation fails.
+     * @param aEncryptedMsg message to decrypt
+     * @return the decrypted message
+     */
+    private native byte[] decryptMessageJni(OlmMessage aEncryptedMsg);
+
+    //==============================================================================================================
+    // Serialization management
+    //==============================================================================================================
+
+    /**
+     * Kick off the serialization mechanism.
+     * @param aOutStream output stream for serializing
+     * @throws IOException exception
+     */
+    private void writeObject(ObjectOutputStream aOutStream) throws IOException {
+        serialize(aOutStream);
+    }
+
+    /**
+     * Kick off the deserialization mechanism.
+     * @param aInStream input stream
+     * @throws IOException exception
+     * @throws ClassNotFoundException exception
+     */
+    private void readObject(ObjectInputStream aInStream) throws Exception {
+        deserialize(aInStream);
+    }
+
+    /**
+     * Return a session as a bytes buffer.<br>
+     * The account is serialized and encrypted with aKey.
+     * In case of failure, an error human readable
+     * description is provide in aErrorMsg.
+     * @param aKey encryption key
+     * @param aErrorMsg error message description
+     * @return session as a bytes buffer
+     */
+    @Override
+    protected byte[] serialize(byte[] aKey, StringBuffer aErrorMsg) {
+        byte[] pickleRetValue = null;
+
+        // sanity check
+        if(null == aErrorMsg) {
+            Log.e(LOG_TAG,"## serializeDataWithKey(): invalid parameter - aErrorMsg=null");
+        } else if (null == aKey) {
+            aErrorMsg.append("Invalid input parameters in serializeDataWithKey()");
+        } else {
+            aErrorMsg.setLength(0);
+            try {
+                pickleRetValue = serializeJni(aKey);
+            } catch (Exception e) {
+                Log.e(LOG_TAG,"## serializeDataWithKey(): failed " + e.getMessage());
+                aErrorMsg.append(e.getMessage());
+            }
+        }
+
+        return pickleRetValue;
+    }
+
+    /**
+     * Serialize and encrypt session instance.<br>
+     * An exception is thrown if the operation fails.
+     * @param aKeyBuffer key used to encrypt the serialized account data
+     * @return the serialised account as bytes buffer.
+     **/
+    private native byte[] serializeJni(byte[] aKeyBuffer);
+
+    /**
+     * Loads an account from a pickled base64 string.<br>
+     * See {@link #serialize(byte[], StringBuffer)}
+     * @param aSerializedData pickled account in a base64 string format
+     * @param aKey key used to encrypted
+     */
+    @Override
+    protected void deserialize(byte[] aSerializedData, byte[] aKey) throws Exception {
+        String errorMsg = null;
+
+        try {
+            if ((null == aSerializedData) || (null == aKey)) {
+                Log.e(LOG_TAG, "## deserialize(): invalid input parameters");
+                errorMsg = "invalid input parameters";
+            } else {
+                mNativeId = deserializeJni(aSerializedData, aKey);
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## deserialize() failed " + e.getMessage());
+            errorMsg = e.getMessage();
+        }
+
+        if (!TextUtils.isEmpty(errorMsg)) {
+            releaseSession();
+            throw new OlmException(OlmException.EXCEPTION_CODE_ACCOUNT_DESERIALIZATION, errorMsg);
+        }
+    }
+    /**
+     * Allocate a new session and initialize it with the serialisation data.<br>
+     * An exception is thrown if the operation fails.
+     * @param aSerializedData the session serialisation buffer
+     * @param aKey the key used to encrypt the serialized account data
+     * @return the deserialized session
+     **/
+    private native long deserializeJni(byte[] aSerializedData, byte[] aKey);
+}
+
diff --git a/android/olm-sdk/src/main/java/org/matrix/olm/OlmUtility.java b/android/olm-sdk/src/main/java/org/matrix/olm/OlmUtility.java
new file mode 100644
index 0000000..bf9ef90
--- /dev/null
+++ b/android/olm-sdk/src/main/java/org/matrix/olm/OlmUtility.java
@@ -0,0 +1,227 @@
+/*
+ * Copyright 2017 OpenMarket Ltd
+ * Copyright 2017 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.olm;
+
+import android.text.TextUtils;
+import android.util.Log;
+
+import org.json.JSONObject;
+
+import java.security.SecureRandom;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+/**
+ * Olm SDK helper class.
+ */
+public class OlmUtility {
+    private static final String LOG_TAG = "OlmUtility";
+
+    public static final int RANDOM_KEY_SIZE = 32;
+
+    /** Instance Id returned by JNI.
+     * This value uniquely identifies this utility instance.
+     **/
+    private long mNativeId;
+
+    public OlmUtility() throws OlmException  {
+        initUtility();
+    }
+
+    /**
+     * Create a native utility instance.
+     * To be called before any other API call.
+     * @exception OlmException the exception
+     */
+    private void initUtility() throws OlmException {
+        try {
+            mNativeId = createUtilityJni();
+        } catch (Exception e) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_UTILITY_CREATION, e.getMessage());
+        }
+    }
+
+    private native long createUtilityJni();
+
+    /**
+     * Release native instance.<br>
+     * Public API for {@link #releaseUtilityJni()}.
+     */
+    public void releaseUtility() {
+        if (0 != mNativeId) {
+            releaseUtilityJni();
+        }
+        mNativeId = 0;
+    }
+    private native void releaseUtilityJni();
+
+    /**
+     * Verify an ed25519 signature.<br>
+     * An exception is thrown if the operation fails.
+     * @param aSignature the base64-encoded message signature to be checked.
+     * @param aFingerprintKey the ed25519 key (fingerprint key)
+     * @param aMessage the signed message
+     * @exception OlmException the failure reason
+     */
+    public void verifyEd25519Signature(String aSignature, String aFingerprintKey, String aMessage) throws OlmException {
+        String errorMessage;
+
+        try {
+            if (TextUtils.isEmpty(aSignature) || TextUtils.isEmpty(aFingerprintKey) || TextUtils.isEmpty(aMessage)) {
+                Log.e(LOG_TAG, "## verifyEd25519Signature(): invalid input parameters");
+                errorMessage = "JAVA sanity check failure - invalid input parameters";
+            } else {
+                errorMessage =  verifyEd25519SignatureJni(aSignature.getBytes("UTF-8"), aFingerprintKey.getBytes("UTF-8"), aMessage.getBytes("UTF-8"));
+            }
+        } catch (Exception e) {
+            Log.e(LOG_TAG, "## verifyEd25519Signature(): failed " + e.getMessage());
+            errorMessage = e.getMessage();
+        }
+
+        if (!TextUtils.isEmpty(errorMessage)) {
+            throw new OlmException(OlmException.EXCEPTION_CODE_UTILITY_VERIFY_SIGNATURE, errorMessage);
+        }
+    }
+
+    /**
+     * Verify an ed25519 signature.
+     * Return a human readable error message in case of verification failure.
+     * @param aSignature the base64-encoded message signature to be checked.
+     * @param aFingerprintKey the ed25519 key
+     * @param aMessage the signed message
+     * @return null if validation succeed, the error message string if operation failed
+     */
+    private native String verifyEd25519SignatureJni(byte[] aSignature, byte[] aFingerprintKey, byte[] aMessage);
+
+    /**
+     * Compute the hash(SHA-256) value of the string given in parameter(aMessageToHash).<br>
+     * The hash value is the returned by the method.
+     * @param aMessageToHash message to be hashed
+     * @return hash value if operation succeed, null otherwise
+     */
+     public String sha256(String aMessageToHash) {
+         String hashRetValue = null;
+
+         if (null != aMessageToHash) {
+             try {
+                 hashRetValue = new String(sha256Jni(aMessageToHash.getBytes("UTF-8")), "UTF-8");
+             } catch (Exception e) {
+                 Log.e(LOG_TAG, "## sha256(): failed " + e.getMessage());
+             }
+         }
+
+        return hashRetValue;
+    }
+
+    /**
+     * Compute the digest (SHA 256) for the message passed in parameter.<br>
+     * The digest value is the function return value.
+     * An exception is thrown if the operation fails.
+     * @param aMessage the message
+     * @return digest of the message.
+     **/
+    private native byte[] sha256Jni(byte[] aMessage);
+
+    /**
+     * Helper method to compute a string based on random integers.
+     * @return bytes buffer containing randoms integer values
+     */
+    public static byte[] getRandomKey() {
+        SecureRandom secureRandom = new SecureRandom();
+        byte[] buffer = new byte[RANDOM_KEY_SIZE];
+        secureRandom.nextBytes(buffer);
+
+        // the key is saved as string
+        // so avoid the UTF8 marker bytes
+        for(int i = 0; i < RANDOM_KEY_SIZE; i++) {
+            buffer[i] = (byte)(buffer[i] & 0x7F);
+        }
+        return buffer;
+    }
+
+    /**
+     * Return true the object resources have been released.<br>
+     * @return true the object resources have been released
+     */
+    public boolean isReleased() {
+        return (0 == mNativeId);
+    }
+
+    /**
+     * Build a string-string dictionary from a jsonObject.<br>
+     * @param jsonObject the object to parse
+     * @return the map
+     */
+    public static Map<String, String> toStringMap(JSONObject jsonObject) {
+        if (null != jsonObject) {
+            HashMap<String, String> map = new HashMap<>();
+            Iterator<String> keysItr = jsonObject.keys();
+            while(keysItr.hasNext()) {
+                String key = keysItr.next();
+                try {
+                    Object value = jsonObject.get(key);
+
+                    if (value instanceof String) {
+                        map.put(key, (String) value);
+                    } else {
+                        Log.e(LOG_TAG, "## toStringMap(): unexpected type " + value.getClass());
+                    }
+                } catch (Exception e) {
+                    Log.e(LOG_TAG, "## toStringMap(): failed " + e.getMessage());
+                }
+            }
+
+            return map;
+        }
+
+        return null;
+    }
+
+    /**
+     * Build a string-string dictionary of string dictionary from a jsonObject.<br>
+     * @param jsonObject the object to parse
+     * @return the map
+     */
+    public static Map<String, Map<String, String>> toStringMapMap(JSONObject jsonObject) {
+        if (null != jsonObject) {
+            HashMap<String, Map<String, String>> map = new HashMap<>();
+
+            Iterator<String> keysItr = jsonObject.keys();
+            while(keysItr.hasNext()) {
+                String key = keysItr.next();
+                try {
+                    Object value = jsonObject.get(key);
+
+                    if (value instanceof JSONObject) {
+                        map.put(key, toStringMap((JSONObject) value));
+                    } else {
+                        Log.e(LOG_TAG, "## toStringMapMap(): unexpected type " + value.getClass());
+                    }
+                } catch (Exception e) {
+                    Log.e(LOG_TAG, "## toStringMapMap(): failed " + e.getMessage());
+                }
+            }
+
+            return map;
+        }
+
+        return null;
+    }
+}
+
diff --git a/android/olm-sdk/src/main/jni/Android.mk b/android/olm-sdk/src/main/jni/Android.mk
new file mode 100644
index 0000000..97d747c
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/Android.mk
@@ -0,0 +1,59 @@
+LOCAL_PATH := $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := olm
+MAJOR := 2
+MINOR := 0
+PATCH := 0
+OLM_VERSION := $(MAJOR).$(MINOR).$(PATCH)
+SRC_ROOT_DIR := ../../../../..
+
+$(info LOCAL_PATH=$(LOCAL_PATH))
+$(info SRC_ROOT_DIR=$(SRC_ROOT_DIR))
+$(info OLM_VERSION=$(OLM_VERSION))
+
+LOCAL_CPPFLAGS+= -std=c++11 -Wall
+LOCAL_CONLYFLAGS+= -std=c99
+LOCAL_CFLAGS+= -DOLMLIB_VERSION_MAJOR=$(MAJOR) \
+-DOLMLIB_VERSION_MINOR=$(MINOR) \
+-DOLMLIB_VERSION_PATCH=$(PATCH)
+
+#LOCAL_CFLAGS+= -DNDK_DEBUG
+
+LOCAL_C_INCLUDES+= $(LOCAL_PATH)/$(SRC_ROOT_DIR)/include/ \
+$(LOCAL_PATH)/$(SRC_ROOT_DIR)/lib
+
+$(info LOCAL_C_INCLUDES=$(LOCAL_C_INCLUDES))
+
+LOCAL_SRC_FILES := $(SRC_ROOT_DIR)/src/account.cpp \
+$(SRC_ROOT_DIR)/src/base64.cpp \
+$(SRC_ROOT_DIR)/src/cipher.cpp \
+$(SRC_ROOT_DIR)/src/crypto.cpp \
+$(SRC_ROOT_DIR)/src/memory.cpp \
+$(SRC_ROOT_DIR)/src/message.cpp \
+$(SRC_ROOT_DIR)/src/olm.cpp \
+$(SRC_ROOT_DIR)/src/pickle.cpp \
+$(SRC_ROOT_DIR)/src/ratchet.cpp \
+$(SRC_ROOT_DIR)/src/session.cpp \
+$(SRC_ROOT_DIR)/src/utility.cpp \
+$(SRC_ROOT_DIR)/src/ed25519.c \
+$(SRC_ROOT_DIR)/src/error.c \
+$(SRC_ROOT_DIR)/src/inbound_group_session.c \
+$(SRC_ROOT_DIR)/src/megolm.c \
+$(SRC_ROOT_DIR)/src/outbound_group_session.c \
+$(SRC_ROOT_DIR)/src/pickle_encoding.c \
+$(SRC_ROOT_DIR)/lib/crypto-algorithms/sha256.c \
+$(SRC_ROOT_DIR)/lib/crypto-algorithms/aes.c \
+$(SRC_ROOT_DIR)/lib/curve25519-donna/curve25519-donna.c \
+olm_account.cpp \
+olm_session.cpp \
+olm_jni_helper.cpp \
+olm_inbound_group_session.cpp \
+olm_outbound_group_session.cpp \
+olm_utility.cpp \
+olm_manager.cpp
+
+LOCAL_LDLIBS := -llog
+
+include $(BUILD_SHARED_LIBRARY)
+
diff --git a/android/olm-sdk/src/main/jni/Application.mk b/android/olm-sdk/src/main/jni/Application.mk
new file mode 100644
index 0000000..6516f5e
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/Application.mk
@@ -0,0 +1,3 @@
+APP_PLATFORM := android-16
+APP_ABI := arm64-v8a armeabi-v7a armeabi x86_64  x86
+APP_STL := gnustl_static
\ No newline at end of file
diff --git a/android/olm-sdk/src/main/jni/olm_account.cpp b/android/olm-sdk/src/main/jni/olm_account.cpp
new file mode 100644
index 0000000..40081ac
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_account.cpp
@@ -0,0 +1,687 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "olm_account.h"
+
+using namespace AndroidOlmSdk;
+
+/**
+ * Init memory allocation for account creation.
+ * @return valid memory allocation, NULL otherwise
+ **/
+OlmAccount* initializeAccountMemory()
+{
+    size_t accountSize = olm_account_size();
+    OlmAccount* accountPtr = (OlmAccount*)malloc(accountSize);
+
+    if (accountPtr)
+    {
+        // init account object
+        accountPtr = olm_account(accountPtr);
+        LOGD("## initializeAccountMemory(): success - OLM account size=%lu",static_cast<long unsigned int>(accountSize));
+    }
+    else
+    {
+        LOGE("## initializeAccountMemory(): failure - OOM");
+    }
+
+    return accountPtr;
+}
+
+/**
+ * Create a new account and return it to JAVA side.<br>
+ * Since a C prt is returned as a jlong, special care will be taken
+ * to make the cast (OlmAccount* => jlong) platform independent.
+ * @return the initialized OlmAccount* instance or throw an exception if fails
+ **/
+JNIEXPORT jlong OLM_ACCOUNT_FUNC_DEF(createNewAccountJni)(JNIEnv *env, jobject thiz)
+{
+    const char* errorMessage = NULL;
+    OlmAccount *accountPtr = initializeAccountMemory();
+
+    // init account memory allocation
+    if (!accountPtr)
+    {
+        LOGE("## initNewAccount(): failure - init account OOM");
+        errorMessage = "init account OOM";
+    }
+    else
+    {
+        // get random buffer size
+        size_t randomSize = olm_create_account_random_length(accountPtr);
+
+        LOGD("## initNewAccount(): randomSize=%lu", static_cast<long unsigned int>(randomSize));
+
+        uint8_t *randomBuffPtr = NULL;
+        size_t accountRetCode;
+
+        // allocate random buffer
+        if ((0 != randomSize) && !setRandomInBuffer(env, &randomBuffPtr, randomSize))
+        {
+            LOGE("## initNewAccount(): failure - random buffer init");
+            errorMessage = "random buffer init";
+        }
+        else
+        {
+            // create account
+            accountRetCode = olm_create_account(accountPtr, (void*)randomBuffPtr, randomSize);
+
+            if (accountRetCode == olm_error())
+            {
+                LOGE("## initNewAccount(): failure - account creation failed Msg=%s", olm_account_last_error(accountPtr));
+                errorMessage = olm_account_last_error(accountPtr);
+            }
+
+            LOGD("## initNewAccount(): success - OLM account created");
+            LOGD("## initNewAccount(): success - accountPtr=%p (jlong)(intptr_t)accountPtr=%lld",accountPtr,(jlong)(intptr_t)accountPtr);
+        }
+
+        if (randomBuffPtr)
+        {
+            memset(randomBuffPtr, 0, randomSize);
+            free(randomBuffPtr);
+        }
+    }
+
+    if (errorMessage)
+    {
+        // release the allocated data
+        if (accountPtr)
+        {
+            olm_clear_account(accountPtr);
+            free(accountPtr);
+        }
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return (jlong)(intptr_t)accountPtr;
+}
+/**
+ * Release the account allocation made by initializeAccountMemory().<br>
+ * This method MUST be called when java counter part account instance is done.
+ */
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(releaseAccountJni)(JNIEnv *env, jobject thiz)
+{
+    LOGD("## releaseAccountJni(): IN");
+
+    OlmAccount* accountPtr = getAccountInstanceId(env, thiz);
+
+    if (!accountPtr)
+    {
+        LOGE(" ## releaseAccountJni(): failure - invalid Account ptr=NULL");
+    }
+    else
+    {
+        LOGD(" ## releaseAccountJni(): accountPtr=%p",accountPtr);
+        olm_clear_account(accountPtr);
+
+        LOGD(" ## releaseAccountJni(): IN");
+        // even if free(NULL) does not crash, logs are performed for debug purpose
+        free(accountPtr);
+        LOGD(" ## releaseAccountJni(): OUT");
+    }
+}
+
+// *********************************************************************
+// ************************* IDENTITY KEYS API *************************
+// *********************************************************************
+
+/**
+ * Get identity keys: Ed25519 fingerprint key and Curve25519 identity key.<br>
+ * The keys are returned in the byte array.
+ * @return the identity keys or throw an exception if it fails
+ **/
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(identityKeysJni)(JNIEnv *env, jobject thiz)
+{
+    const char* errorMessage = NULL;
+    jbyteArray byteArrayRetValue = NULL;
+    OlmAccount* accountPtr = getAccountInstanceId(env, thiz);
+
+    if (!accountPtr)
+    {
+        LOGE("## identityKeys(): failure - invalid Account ptr=NULL");
+        errorMessage = "invalid Account ptr";
+    }
+    else
+    {
+        LOGD("## identityKeys(): accountPtr =%p", accountPtr);
+
+        // identity keys allocation
+        size_t identityKeysLength = olm_account_identity_keys_length(accountPtr);
+        uint8_t *identityKeysBytesPtr = (uint8_t*)malloc(identityKeysLength);
+
+        if (!identityKeysBytesPtr)
+        {
+            LOGE("## identityKeys(): failure - identity keys array OOM");
+            errorMessage = "identity keys array OOM";
+        }
+        else
+        {
+            // retrieve key pairs in identityKeysBytesPtr
+            size_t keysResult = olm_account_identity_keys(accountPtr, identityKeysBytesPtr, identityKeysLength);
+
+            if (keysResult == olm_error())
+            {
+                errorMessage = (const char *)olm_account_last_error(accountPtr);
+                LOGE("## identityKeys(): failure - error getting identity keys Msg=%s", errorMessage);
+            }
+            else
+            {
+                // allocate the byte array to be returned to java
+                byteArrayRetValue = env->NewByteArray(identityKeysLength);
+
+                if (!byteArrayRetValue)
+                {
+                    LOGE("## identityKeys(): failure - return byte array OOM");
+                    errorMessage = "byte array OOM";
+                }
+                else
+                {
+                    env->SetByteArrayRegion(byteArrayRetValue, 0/*offset*/, identityKeysLength, (const jbyte*)identityKeysBytesPtr);
+                    LOGD("## identityKeys(): success - result=%lu", static_cast<long unsigned int>(keysResult));
+                }
+            }
+
+            free(identityKeysBytesPtr);
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return byteArrayRetValue;
+}
+
+// *********************************************************************
+// ************************* ONE TIME KEYS API *************************
+// *********************************************************************
+
+/**
+ * Get the public parts of the unpublished "one time keys" for the account.<br>
+ * The returned data is a JSON-formatted object with the single property
+ * <tt>curve25519</tt>, which is itself an object mapping key id to
+ * base64-encoded Curve25519 key.<br>
+ * @return byte array containing the one time keys or throw an exception if it fails
+ */
+JNIEXPORT jlong OLM_ACCOUNT_FUNC_DEF(maxOneTimeKeysJni)(JNIEnv *env, jobject thiz)
+{
+    OlmAccount* accountPtr = getAccountInstanceId(env, thiz);
+    size_t maxKeys = -1;
+
+    if (!accountPtr)
+    {
+        LOGE("## maxOneTimeKey(): failure - invalid Account ptr=NULL");
+    }
+    else
+    {
+        maxKeys = olm_account_max_number_of_one_time_keys(accountPtr);
+    }
+
+    LOGD("## maxOneTimeKey(): Max keys=%lu", static_cast<long unsigned int>(maxKeys));
+
+    return (jlong)maxKeys;
+}
+
+/**
+ * Generate "one time keys".
+ * An exception is thrown if the operation fails.
+ * @param aNumberOfKeys number of keys to generate
+ **/
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(generateOneTimeKeysJni)(JNIEnv *env, jobject thiz, jint aNumberOfKeys)
+{
+    const char* errorMessage = NULL;
+    OlmAccount *accountPtr = getAccountInstanceId(env, thiz);
+
+    if (!accountPtr)
+    {
+        LOGE("## generateOneTimeKeysJni(): failure - invalid Account ptr");
+        errorMessage = "invalid Account ptr";
+    }
+    else
+    {
+        // keys memory allocation
+        size_t randomLength = olm_account_generate_one_time_keys_random_length(accountPtr, (size_t)aNumberOfKeys);
+        LOGD("## generateOneTimeKeysJni(): randomLength=%lu", static_cast<long unsigned int>(randomLength));
+
+        uint8_t *randomBufferPtr = NULL;
+
+        if ((0 != randomLength) && !setRandomInBuffer(env, &randomBufferPtr, randomLength))
+        {
+            LOGE("## generateOneTimeKeysJni(): failure - random buffer init");
+            errorMessage = "random buffer init";
+        }
+        else
+        {
+            LOGD("## generateOneTimeKeysJni(): accountPtr =%p aNumberOfKeys=%d",accountPtr, aNumberOfKeys);
+
+            // retrieve key pairs in keysBytesPtr
+            size_t result = olm_account_generate_one_time_keys(accountPtr, (size_t)aNumberOfKeys, (void*)randomBufferPtr, randomLength);
+
+            if (result == olm_error())
+            {
+                errorMessage = olm_account_last_error(accountPtr);
+                LOGE("## generateOneTimeKeysJni(): failure - error generating one time keys Msg=%s", errorMessage);
+            }
+            else
+            {
+                LOGD("## generateOneTimeKeysJni(): success - result=%lu", static_cast<long unsigned int>(result));
+            }
+        }
+
+
+        if (randomBufferPtr)
+        {
+            memset(randomBufferPtr, 0, randomLength);
+            free(randomBufferPtr);
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+}
+
+/**
+ * Get "one time keys".<br>
+ * Return the public parts of the unpublished "one time keys" for the account
+ * @return a valid byte array if operation succeed, null otherwise
+ **/
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(oneTimeKeysJni)(JNIEnv *env, jobject thiz)
+{
+    const char* errorMessage = NULL;
+    jbyteArray byteArrayRetValue = NULL;
+    OlmAccount* accountPtr = getAccountInstanceId(env, thiz);
+
+    LOGD("## oneTimeKeysJni(): IN");
+
+    if (!accountPtr)
+    {
+        LOGE("## oneTimeKeysJni(): failure - invalid Account ptr");
+        errorMessage = "invalid Account ptr";
+    }
+    else
+    {
+        // keys memory allocation
+        size_t keysLength = olm_account_one_time_keys_length(accountPtr);
+        uint8_t *keysBytesPtr = (uint8_t *)malloc(keysLength*sizeof(uint8_t));
+
+        if (!keysBytesPtr)
+        {
+            LOGE("## oneTimeKeysJni(): failure - one time keys array OOM");
+            errorMessage = "one time keys array OOM";
+        }
+        else
+        {
+            // retrieve key pairs in keysBytesPtr
+            size_t keysResult = olm_account_one_time_keys(accountPtr, keysBytesPtr, keysLength);
+
+            if (keysResult == olm_error()) {
+                LOGE("## oneTimeKeysJni(): failure - error getting one time keys Msg=%s",(const char *)olm_account_last_error(accountPtr));
+                errorMessage = (const char *)olm_account_last_error(accountPtr);
+            }
+            else
+            {
+                // allocate the byte array to be returned to java
+                byteArrayRetValue = env->NewByteArray(keysLength);
+
+                if (!byteArrayRetValue)
+                {
+                    LOGE("## oneTimeKeysJni(): failure - return byte array OOM");
+                    errorMessage = "return byte array OOM";
+                }
+                else
+                {
+                    env->SetByteArrayRegion(byteArrayRetValue, 0/*offset*/, keysLength, (const jbyte*)keysBytesPtr);
+                    LOGD("## oneTimeKeysJni(): success");
+                }
+            }
+
+            free(keysBytesPtr);
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return byteArrayRetValue;
+}
+
+/**
+ * Remove the "one time keys"  that the session used from the account.
+ * An exception is thrown if the operation fails.
+ * @param aNativeOlmSessionId session instance
+ **/
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(removeOneTimeKeysJni)(JNIEnv *env, jobject thiz, jlong aNativeOlmSessionId)
+{
+    const char* errorMessage = NULL;
+    OlmAccount* accountPtr = NULL;
+    OlmSession* sessionPtr = (OlmSession*)aNativeOlmSessionId;
+
+    if (!sessionPtr)
+    {
+        LOGE("## removeOneTimeKeysJni(): failure - invalid session ptr");
+        errorMessage = "invalid session ptr";
+    }
+    else if (!(accountPtr = getAccountInstanceId(env, thiz)))
+    {
+        LOGE("## removeOneTimeKeysJni(): failure - invalid account ptr");
+        errorMessage = "invalid account ptr";
+    }
+    else
+    {
+        size_t result = olm_remove_one_time_keys(accountPtr, sessionPtr);
+
+        if (result == olm_error())
+        {   // the account doesn't have any matching "one time keys"..
+            LOGW("## removeOneTimeKeysJni(): failure - removing one time keys Msg=%s", olm_account_last_error(accountPtr));
+            errorMessage = (const char *)olm_account_last_error(accountPtr);
+        }
+        else
+        {
+            LOGD("## removeOneTimeKeysJni(): success");
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+}
+
+/**
+ * Mark the current set of "one time keys" as being published.
+ * An exception is thrown if the operation fails.
+ **/
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(markOneTimeKeysAsPublishedJni)(JNIEnv *env, jobject thiz)
+{
+    const char* errorMessage = NULL;
+    OlmAccount* accountPtr = getAccountInstanceId(env, thiz);
+
+    if (!accountPtr)
+    {
+        LOGE("## markOneTimeKeysAsPublishedJni(): failure - invalid account ptr");
+        errorMessage = "invalid account ptr";
+    }
+    else
+    {
+        size_t result = olm_account_mark_keys_as_published(accountPtr);
+
+        if (result == olm_error())
+        {
+            LOGW("## markOneTimeKeysAsPublishedJni(): failure - Msg=%s",(const char *)olm_account_last_error(accountPtr));
+            errorMessage = (const char *)olm_account_last_error(accountPtr);
+        }
+        else
+        {
+            LOGD("## markOneTimeKeysAsPublishedJni(): success - retCode=%lu",static_cast<long unsigned int>(result));
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+}
+
+/**
+ * Sign a message with the ed25519 key (fingerprint) for this account.<br>
+ * The signed message is returned by the function.
+ * @param aMessage message to sign
+ * @return the signed message, null otherwise
+ **/
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(signMessageJni)(JNIEnv *env, jobject thiz, jbyteArray aMessage)
+{
+    const char* errorMessage = NULL;
+    OlmAccount* accountPtr = NULL;
+    jbyteArray signedMsgRetValueBuffer = NULL;
+
+    if (!aMessage)
+    {
+        LOGE("## signMessageJni(): failure - invalid aMessage param");
+        errorMessage = "invalid aMessage param";
+    }
+    else if (!(accountPtr = getAccountInstanceId(env, thiz)))
+    {
+        LOGE("## signMessageJni(): failure - invalid account ptr");
+        errorMessage = "invalid account ptr";
+    }
+    else
+    {
+        int messageLength = env->GetArrayLength(aMessage);
+        jbyte* messageToSign = env->GetByteArrayElements(aMessage, NULL);
+
+        // signature memory allocation
+        size_t signatureLength = olm_account_signature_length(accountPtr);
+        void* signedMsgPtr = malloc(signatureLength * sizeof(uint8_t));
+
+        if (!signedMsgPtr)
+        {
+            LOGE("## signMessageJni(): failure - signature allocation OOM");
+            errorMessage = "signature allocation OOM";
+        }
+        else
+        {
+            // sign message
+            size_t resultSign = olm_account_sign(accountPtr,
+                                   (void*)messageToSign,
+                                   (size_t)messageLength,
+                                   signedMsgPtr,
+                                   signatureLength);
+
+            if (resultSign == olm_error())
+            {
+                LOGE("## signMessageJni(): failure - error signing message Msg=%s",(const char *)olm_account_last_error(accountPtr));
+                errorMessage = (const char *)olm_account_last_error(accountPtr);
+            }
+            else
+            {
+                LOGD("## signMessageJni(): success - retCode=%lu signatureLength=%lu", static_cast<long unsigned int>(resultSign), static_cast<long unsigned int>(signatureLength));
+     	
+                signedMsgRetValueBuffer = env->NewByteArray(signatureLength);
+                env->SetByteArrayRegion(signedMsgRetValueBuffer, 0 , signatureLength, (jbyte*)signedMsgPtr);
+            }
+
+            free(signedMsgPtr);
+        }
+
+        // release messageToSign
+        if (messageToSign)
+        {
+            env->ReleaseByteArrayElements(aMessage, messageToSign, JNI_ABORT);
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return signedMsgRetValueBuffer;
+}
+
+/**
+ * Serialize and encrypt account instance.<br>
+ * @param aKeyBuffer key used to encrypt the serialized account data
+ * @return the serialised account as bytes buffer.
+ **/
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(serializeJni)(JNIEnv *env, jobject thiz, jbyteArray aKeyBuffer)
+{
+    const char* errorMessage = NULL;
+    jbyteArray pickledDataRetValue = 0;
+    jbyte* keyPtr = NULL;
+    OlmAccount* accountPtr = NULL;
+
+    LOGD("## serializeJni(): IN");
+
+    if (!aKeyBuffer)
+    {
+        LOGE(" ## serializeJni(): failure - invalid key");
+        errorMessage = "invalid key";
+    }
+    else if (!(accountPtr = getAccountInstanceId(env, thiz)))
+    {
+       LOGE(" ## serializeJni(): failure - invalid account ptr");
+       errorMessage = "invalid account ptr";
+    }
+    else if (!(keyPtr = env->GetByteArrayElements(aKeyBuffer, NULL)))
+    {
+        LOGE(" ## serializeJni(): failure - keyPtr JNI allocation OOM");
+        errorMessage = "keyPtr JNI allocation OOM";
+    }
+    else
+    {
+        size_t pickledLength = olm_pickle_account_length(accountPtr);
+        size_t keyLength = (size_t)env->GetArrayLength(aKeyBuffer);
+        LOGD(" ## serializeJni(): pickledLength=%lu keyLength=%lu",static_cast<long unsigned int>(pickledLength), static_cast<long unsigned int>(keyLength));
+
+        void* pickledPtr = malloc(pickledLength * sizeof(uint8_t));
+
+        if (!pickledPtr)
+        {
+            LOGE(" ## serializeJni(): failure - pickledPtr buffer OOM");
+            errorMessage = "pickledPtr buffer OOM";
+        }
+        else
+        {
+            size_t result = olm_pickle_account(accountPtr,
+                                               (void const *)keyPtr,
+                                               keyLength,
+                                               (void*)pickledPtr,
+                                               pickledLength);
+            if (result == olm_error())
+            {
+                errorMessage = olm_account_last_error(accountPtr);
+                LOGE(" ## serializeJni(): failure - olm_pickle_account() Msg=%s", errorMessage);
+            }
+            else
+            {
+                LOGD(" ## serializeJni(): success - result=%lu pickled=%.*s", static_cast<long unsigned int>(result), static_cast<int>(pickledLength), static_cast<char*>(pickledPtr));
+                pickledDataRetValue = env->NewByteArray(pickledLength);
+                env->SetByteArrayRegion(pickledDataRetValue, 0 , pickledLength, (jbyte*)pickledPtr);
+            }
+
+            free(pickledPtr);
+        }
+    }
+
+    // free alloc
+    if (keyPtr)
+    {
+        env->ReleaseByteArrayElements(aKeyBuffer, keyPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return pickledDataRetValue;
+}
+
+/**
+ * Allocate a new account and initialise it with the serialisation data.<br>
+ * @param aSerializedDataBuffer the account serialisation buffer
+ * @param aKeyBuffer the key used to encrypt the serialized account data
+ * @return the deserialised account
+ **/
+JNIEXPORT jlong OLM_ACCOUNT_FUNC_DEF(deserializeJni)(JNIEnv *env, jobject thiz, jbyteArray aSerializedDataBuffer, jbyteArray aKeyBuffer)
+{
+    const char* errorMessage = NULL;
+
+    OlmAccount* accountPtr = NULL;
+
+    jbyte* keyPtr = NULL;
+    jbyte* pickledPtr = NULL;
+
+    LOGD("## deserializeJni(): IN");
+
+    if (!aKeyBuffer)
+    {
+        LOGE(" ## deserializeJni(): failure - invalid key");
+        errorMessage = "invalid key";
+    }
+    else if (!aSerializedDataBuffer)
+    {
+        LOGE(" ## deserializeJni(): failure - invalid serialized data");
+        errorMessage = "invalid serialized data";
+    }
+    else if (!(accountPtr = initializeAccountMemory()))
+    {
+        LOGE(" ## deserializeJni(): failure - account failure OOM");
+        errorMessage = "account failure OOM";
+    }
+    else if (!(keyPtr = env->GetByteArrayElements(aKeyBuffer, 0)))
+    {
+        LOGE(" ## deserializeJni(): failure - keyPtr JNI allocation OOM");
+        errorMessage = "keyPtr JNI allocation OOM";
+    }
+    else if (!(pickledPtr = env->GetByteArrayElements(aSerializedDataBuffer, 0)))
+    {
+        LOGE(" ## deserializeJni(): failure - pickledPtr JNI allocation OOM");
+        errorMessage = "pickledPtr JNI allocation OOM";
+    }
+    else
+    {
+        size_t pickledLength = (size_t)env->GetArrayLength(aSerializedDataBuffer);
+        size_t keyLength = (size_t)env->GetArrayLength(aKeyBuffer);
+        LOGD(" ## deserializeJni(): pickledLength=%lu keyLength=%lu",static_cast<long unsigned int>(pickledLength), static_cast<long unsigned int>(keyLength));
+        LOGD(" ## deserializeJni(): pickled=%.*s", static_cast<int> (pickledLength), (char const *)pickledPtr);
+
+        size_t result = olm_unpickle_account(accountPtr,
+                                             (void const *)keyPtr,
+                                             keyLength,
+                                             (void*)pickledPtr,
+                                             pickledLength);
+        if (result == olm_error())
+        {
+            errorMessage = olm_account_last_error(accountPtr);
+            LOGE(" ## deserializeJni(): failure - olm_unpickle_account() Msg=%s", errorMessage);
+        }
+        else
+        {
+            LOGD(" ## deserializeJni(): success - result=%lu ", static_cast<long unsigned int>(result));
+        }
+    }
+
+    // free alloc
+    if (keyPtr)
+    {
+        env->ReleaseByteArrayElements(aKeyBuffer, keyPtr, JNI_ABORT);
+    }
+
+    if (pickledPtr)
+    {
+        env->ReleaseByteArrayElements(aSerializedDataBuffer, pickledPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        if (accountPtr)
+        {
+            olm_clear_account(accountPtr);
+            free(accountPtr);
+        }
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return (jlong)(intptr_t)accountPtr;
+}
\ No newline at end of file
diff --git a/android/olm-sdk/src/main/jni/olm_account.h b/android/olm-sdk/src/main/jni/olm_account.h
new file mode 100644
index 0000000..42b2c2a
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_account.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2017 OpenMarket Ltd
+ * Copyright 2017 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _OMLACCOUNT_H
+#define _OMLACCOUNT_H
+
+#include "olm_jni.h"
+#include "olm/olm.h"
+
+#define OLM_ACCOUNT_FUNC_DEF(func_name) FUNC_DEF(OlmAccount,func_name)
+#define OLM_MANAGER_FUNC_DEF(func_name) FUNC_DEF(OlmManager,func_name)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// account creation/destruction
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(releaseAccountJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jlong OLM_ACCOUNT_FUNC_DEF(createNewAccountJni)(JNIEnv *env, jobject thiz);
+
+// identity keys
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(identityKeysJni)(JNIEnv *env, jobject thiz);
+
+// one time keys
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(oneTimeKeysJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jlong OLM_ACCOUNT_FUNC_DEF(maxOneTimeKeysJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(generateOneTimeKeysJni)(JNIEnv *env, jobject thiz, jint aNumberOfKeys);
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(removeOneTimeKeysJni)(JNIEnv *env, jobject thiz, jlong aNativeOlmSessionId);
+JNIEXPORT void OLM_ACCOUNT_FUNC_DEF(markOneTimeKeysAsPublishedJni)(JNIEnv *env, jobject thiz);
+
+// signing
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(signMessageJni)(JNIEnv *env, jobject thiz, jbyteArray aMessage);
+
+// serialization
+JNIEXPORT jbyteArray OLM_ACCOUNT_FUNC_DEF(serializeJni)(JNIEnv *env, jobject thiz, jbyteArray aKeyBuffer);
+JNIEXPORT jlong OLM_ACCOUNT_FUNC_DEF(deserializeJni)(JNIEnv *env, jobject thiz, jbyteArray aSerializedDataBuffer, jbyteArray aKeyBuffer);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/android/olm-sdk/src/main/jni/olm_inbound_group_session.cpp b/android/olm-sdk/src/main/jni/olm_inbound_group_session.cpp
new file mode 100644
index 0000000..23910bb
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_inbound_group_session.cpp
@@ -0,0 +1,507 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "olm_inbound_group_session.h"
+
+using namespace AndroidOlmSdk;
+
+/**
+ * Release the session allocation made by initializeInboundGroupSessionMemory().<br>
+ * This method MUST be called when java counter part account instance is done.
+ */
+JNIEXPORT void OLM_INBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env, jobject thiz)
+{
+    OlmInboundGroupSession* sessionPtr = getInboundGroupSessionInstanceId(env,thiz);
+
+    LOGD("## releaseSessionJni(): InBound group session IN");
+
+    if (!sessionPtr)
+    {
+        LOGE("## releaseSessionJni(): failure - invalid inbound group session instance");
+    }
+    else
+    {
+        LOGD(" ## releaseSessionJni(): sessionPtr=%p", sessionPtr);
+#ifdef ENABLE_JNI_LOG
+        size_t retCode = olm_clear_inbound_group_session(sessionPtr);
+        LOGD(" ## releaseSessionJni(): clear_inbound_group_session=%lu",static_cast<long unsigned int>(retCode));
+#else
+        olm_clear_inbound_group_session(sessionPtr);
+#endif
+
+        LOGD(" ## releaseSessionJni(): free IN");
+        free(sessionPtr);
+        LOGD(" ## releaseSessionJni(): free OUT");
+    }
+}
+
+/**
+ * Initialize a new inbound group session and return it to JAVA side.<br>
+ * Since a C prt is returned as a jlong, special care will be taken
+ * to make the cast (OlmInboundGroupSession* => jlong) platform independent.
+ * @param aSessionKeyBuffer session key from an outbound session
+ * @return the initialized OlmInboundGroupSession* instance or throw an exception it fails.
+ **/
+JNIEXPORT jlong OLM_INBOUND_GROUP_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz, jbyteArray aSessionKeyBuffer)
+{
+    const char* errorMessage = NULL;
+    OlmInboundGroupSession* sessionPtr = NULL;
+    jbyte* sessionKeyPtr = NULL;
+    size_t sessionSize = olm_inbound_group_session_size();
+
+    LOGD("## createNewSessionJni(): inbound group session IN");
+
+    if (!sessionSize)
+    {
+        LOGE(" ## createNewSessionJni(): failure - inbound group session size = 0");
+        errorMessage = "inbound group session size = 0";
+    }
+    else if (!(sessionPtr = (OlmInboundGroupSession*)malloc(sessionSize)))
+    {
+        LOGE(" ## createNewSessionJni(): failure - inbound group session OOM");
+        errorMessage = "inbound group session OOM";
+    }
+    else if (!aSessionKeyBuffer)
+    {
+        LOGE(" ## createNewSessionJni(): failure - invalid aSessionKey");
+        errorMessage = "invalid aSessionKey";
+    }
+    else if (!(sessionKeyPtr = env->GetByteArrayElements(aSessionKeyBuffer, 0)))
+    {
+        LOGE(" ## createNewSessionJni(): failure - session key JNI allocation OOM");
+        errorMessage = "Session key JNI allocation OOM";
+    }
+    else
+    {
+        sessionPtr = olm_inbound_group_session(sessionPtr);
+
+        size_t sessionKeyLength = (size_t)env->GetArrayLength(aSessionKeyBuffer);
+        LOGD(" ## createNewSessionJni(): sessionKeyLength=%lu", static_cast<long unsigned int>(sessionKeyLength));
+
+        size_t sessionResult = olm_init_inbound_group_session(sessionPtr, (const uint8_t*)sessionKeyPtr, sessionKeyLength);
+
+        if (sessionResult == olm_error())
+        {
+            errorMessage = olm_inbound_group_session_last_error(sessionPtr);
+            LOGE(" ## createNewSessionJni(): failure - init inbound session creation Msg=%s", errorMessage);
+        }
+        else
+        {
+            LOGD(" ## createNewSessionJni(): success - result=%lu", static_cast<long unsigned int>(sessionResult));
+        }
+    }
+
+    if (sessionKeyPtr)
+    {
+        env->ReleaseByteArrayElements(aSessionKeyBuffer, sessionKeyPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    if (errorMessage)
+    {
+        // release the allocated session
+        if (sessionPtr)
+        {
+            olm_clear_inbound_group_session(sessionPtr);
+            free(sessionPtr);
+        }
+
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return (jlong)(intptr_t)sessionPtr;
+}
+
+/**
+ * Get a base64-encoded identifier for this inbound group session.
+ * An exception is thrown if the operation fails.
+ * @return the base64-encoded identifier
+ */
+JNIEXPORT jbyteArray OLM_INBOUND_GROUP_SESSION_FUNC_DEF(sessionIdentifierJni)(JNIEnv *env, jobject thiz)
+{
+    const char* errorMessage = NULL;
+    OlmInboundGroupSession *sessionPtr = getInboundGroupSessionInstanceId(env, thiz);
+    jbyteArray returnValue = 0;
+
+    LOGD("## sessionIdentifierJni(): inbound group session IN");
+
+    if (!sessionPtr)
+    {
+        LOGE(" ## sessionIdentifierJni(): failure - invalid inbound group session instance");
+        errorMessage = "invalid inbound group session instance";
+    }
+    else
+    {
+        // get the size to alloc
+        size_t lengthSessionId = olm_inbound_group_session_id_length(sessionPtr);
+        LOGD(" ## sessionIdentifierJni(): inbound group session lengthSessionId=%lu",static_cast<long unsigned int>(lengthSessionId));
+
+        uint8_t *sessionIdPtr = (uint8_t*)malloc(lengthSessionId*sizeof(uint8_t));
+
+        if (!sessionIdPtr)
+        {
+            LOGE(" ## sessionIdentifierJni(): failure - inbound group session identifier allocation OOM");
+            errorMessage = "inbound group session identifier allocation OOM";
+        }
+        else
+        {
+            size_t result = olm_inbound_group_session_id(sessionPtr, sessionIdPtr, lengthSessionId);
+
+            if (result == olm_error())
+            {
+                errorMessage = (const char *)olm_inbound_group_session_last_error(sessionPtr);
+                LOGE(" ## sessionIdentifierJni(): failure - get inbound group session identifier failure Msg=%s",(const char *)olm_inbound_group_session_last_error(sessionPtr));
+            }
+            else
+            {
+                LOGD(" ## sessionIdentifierJni(): success - inbound group session result=%lu sessionId=%.*s",static_cast<long unsigned int>(result), static_cast<int>(result), (char*)sessionIdPtr);
+
+                returnValue = env->NewByteArray(result);
+                env->SetByteArrayRegion(returnValue, 0 , result, (jbyte*)sessionIdPtr);
+            }
+
+            free(sessionIdPtr);
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return returnValue;
+}
+
+/**
+ * Decrypt a message.
+ * An exception is thrown if the operation fails.
+ * @param aEncryptedMsg the encrypted message
+ * @param aDecryptMessageResult the decryptMessage information
+ * @return the decrypted message
+ */
+JNIEXPORT jbyteArray OLM_INBOUND_GROUP_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *env, jobject thiz, jbyteArray aEncryptedMsgBuffer, jobject aDecryptionResult)
+{
+    jbyteArray decryptedMsgBuffer = 0;
+    const char* errorMessage = NULL;
+
+    OlmInboundGroupSession *sessionPtr = getInboundGroupSessionInstanceId(env, thiz);
+    jbyte *encryptedMsgPtr = NULL;
+    jclass indexObjJClass = 0;
+    jfieldID indexMsgFieldId;
+
+    LOGD("## decryptMessageJni(): inbound group session IN");
+
+    if (!sessionPtr)
+    {
+        LOGE(" ## decryptMessageJni(): failure - invalid inbound group session ptr=NULL");
+        errorMessage = "invalid inbound group session ptr=NULL";
+    }
+    else if (!aEncryptedMsgBuffer)
+    {
+        LOGE(" ## decryptMessageJni(): failure - invalid encrypted message");
+        errorMessage = "invalid encrypted message";
+    }
+    else if (!aDecryptionResult)
+    {
+        LOGE(" ## decryptMessageJni(): failure - invalid index object");
+        errorMessage = "invalid index object";
+    }
+    else if (!(encryptedMsgPtr = env->GetByteArrayElements(aEncryptedMsgBuffer, 0)))
+    {
+        LOGE(" ## decryptMessageJni(): failure - encrypted message JNI allocation OOM");
+        errorMessage = "encrypted message JNI allocation OOM";
+    }
+    else if (!(indexObjJClass = env->GetObjectClass(aDecryptionResult)))
+    {
+        LOGE("## decryptMessageJni(): failure - unable to get index class");
+        errorMessage = "unable to get index class";
+    }
+    else if (!(indexMsgFieldId = env->GetFieldID(indexObjJClass,"mIndex","J")))
+    {
+        LOGE("## decryptMessageJni(): failure - unable to get index type field");
+        errorMessage = "unable to get index type field";
+    }
+    else
+    {
+        // get encrypted message length
+        size_t encryptedMsgLength = (size_t)env->GetArrayLength(aEncryptedMsgBuffer);
+        uint8_t *tempEncryptedPtr = static_cast<uint8_t*>(malloc(encryptedMsgLength*sizeof(uint8_t)));
+
+        // create a dedicated temp buffer to be used in next Olm API calls
+        if (!tempEncryptedPtr)
+        {
+            LOGE(" ## decryptMessageJni(): failure - tempEncryptedPtr allocation OOM");
+            errorMessage = "tempEncryptedPtr allocation OOM";
+        }
+        else
+        {
+            memcpy(tempEncryptedPtr, encryptedMsgPtr, encryptedMsgLength);
+            LOGD(" ## decryptMessageJni(): encryptedMsgLength=%lu encryptedMsg=%.*s",static_cast<long unsigned int>(encryptedMsgLength), static_cast<int>(encryptedMsgLength), encryptedMsgPtr);
+
+            // get max plaintext length
+            size_t maxPlainTextLength = olm_group_decrypt_max_plaintext_length(sessionPtr,
+                                                                               tempEncryptedPtr,
+                                                                               encryptedMsgLength);
+            if (maxPlainTextLength == olm_error())
+            {
+                errorMessage = olm_inbound_group_session_last_error(sessionPtr);
+                LOGE(" ## decryptMessageJni(): failure - olm_group_decrypt_max_plaintext_length Msg=%s", errorMessage);
+            }
+            else
+            {
+                LOGD(" ## decryptMessageJni(): maxPlaintextLength=%lu",static_cast<long unsigned int>(maxPlainTextLength));
+
+                uint32_t messageIndex = 0;
+
+                // allocate output decrypted message
+                uint8_t *plainTextMsgPtr = static_cast<uint8_t*>(malloc(maxPlainTextLength*sizeof(uint8_t)));
+
+                // decrypt, but before reload encrypted buffer (previous one was destroyed)
+                memcpy(tempEncryptedPtr, encryptedMsgPtr, encryptedMsgLength);
+                size_t plaintextLength = olm_group_decrypt(sessionPtr,
+                                                           tempEncryptedPtr,
+                                                           encryptedMsgLength,
+                                                           plainTextMsgPtr,
+                                                           maxPlainTextLength,
+                                                           &messageIndex);
+                if (plaintextLength == olm_error())
+                {
+                    errorMessage = olm_inbound_group_session_last_error(sessionPtr);
+                    LOGE(" ## decryptMessageJni(): failure - olm_group_decrypt Msg=%s", errorMessage);
+                }
+                else
+                {
+                    // update index
+                    env->SetLongField(aDecryptionResult, indexMsgFieldId, (jlong)messageIndex);
+
+                    decryptedMsgBuffer = env->NewByteArray(plaintextLength);
+                    env->SetByteArrayRegion(decryptedMsgBuffer, 0 , plaintextLength, (jbyte*)plainTextMsgPtr);
+
+                    LOGD(" ## decryptMessageJni(): UTF-8 Conversion - decrypted returnedLg=%lu OK",static_cast<long unsigned int>(plaintextLength));
+                }
+
+                if (plainTextMsgPtr)
+                {
+                    memset(plainTextMsgPtr, 0, maxPlainTextLength*sizeof(uint8_t));
+                    free(plainTextMsgPtr);
+                }
+            }
+
+            if (tempEncryptedPtr)
+            {
+                free(tempEncryptedPtr);
+            }
+        }
+    }
+
+    // free alloc
+    if (encryptedMsgPtr)
+    {
+        env->ReleaseByteArrayElements(aEncryptedMsgBuffer, encryptedMsgPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return decryptedMsgBuffer;
+}
+
+
+/**
+ * Serialize and encrypt session instance into a base64 string.<br>
+ * An exception is thrown if the operation fails.
+ * @param aKeyBuffer key used to encrypt the serialized session data
+ * @return a base64 string if operation succeed, null otherwise
+ **/
+JNIEXPORT jbyteArray OLM_INBOUND_GROUP_SESSION_FUNC_DEF(serializeJni)(JNIEnv *env, jobject thiz, jbyteArray aKeyBuffer)
+{
+    const char* errorMessage = NULL;
+
+    jbyteArray pickledDataRet = 0;
+    jbyte* keyPtr = NULL;
+    OlmInboundGroupSession* sessionPtr = getInboundGroupSessionInstanceId(env, thiz);
+
+    LOGD("## inbound group session serializeJni(): IN");
+
+    if (!sessionPtr)
+    {
+        LOGE(" ## serializeJni(): failure - invalid session ptr");
+        errorMessage = "invalid session ptr";
+    }
+    else if (!aKeyBuffer)
+    {
+        LOGE(" ## serializeJni(): failure - invalid key");
+        errorMessage = "invalid key";
+    }
+    else if (!(keyPtr = env->GetByteArrayElements(aKeyBuffer, 0)))
+    {
+        LOGE(" ## serializeJni(): failure - keyPtr JNI allocation OOM");
+        errorMessage = "keyPtr JNI allocation OOM";
+    }
+    else
+    {
+        size_t pickledLength = olm_pickle_inbound_group_session_length(sessionPtr);
+        size_t keyLength = (size_t)env->GetArrayLength(aKeyBuffer);
+        LOGD(" ## serializeJni(): pickledLength=%lu keyLength=%lu", static_cast<long unsigned int>(pickledLength), static_cast<long unsigned int>(keyLength));
+
+        void *pickledPtr = malloc(pickledLength*sizeof(uint8_t));
+
+        if (!pickledPtr)
+        {
+            LOGE(" ## serializeJni(): failure - pickledPtr buffer OOM");
+            errorMessage = "pickledPtr buffer OOM";
+        }
+        else
+        {
+            size_t result = olm_pickle_inbound_group_session(sessionPtr,
+                                                             (void const *)keyPtr,
+                                                              keyLength,
+                                                              (void*)pickledPtr,
+                                                              pickledLength);
+            if (result == olm_error())
+            {
+                errorMessage = olm_inbound_group_session_last_error(sessionPtr);
+                LOGE(" ## serializeJni(): failure - olm_pickle_outbound_group_session() Msg=%s", errorMessage);
+            }
+            else
+            {
+                LOGD(" ## serializeJni(): success - result=%lu pickled=%.*s", static_cast<long unsigned int>(result), static_cast<int>(pickledLength), static_cast<char*>(pickledPtr));
+
+                pickledDataRet = env->NewByteArray(pickledLength);
+                env->SetByteArrayRegion(pickledDataRet, 0 , pickledLength, (jbyte*)pickledPtr);
+            }
+
+            free(pickledPtr);
+        }
+    }
+
+    // free alloc
+    if (keyPtr)
+    {
+        env->ReleaseByteArrayElements(aKeyBuffer, keyPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return pickledDataRet;
+}
+
+/**
+ * Allocate a new session and initialize it with the serialisation data.<br>
+ * An exception is thrown if the operation fails.
+ * @param aSerializedData the session serialisation buffer
+ * @param aKey the key used to encrypt the serialized account data
+ * @return the deserialized session
+ **/
+JNIEXPORT jlong OLM_INBOUND_GROUP_SESSION_FUNC_DEF(deserializeJni)(JNIEnv *env, jobject thiz, jbyteArray aSerializedDataBuffer, jbyteArray aKeyBuffer)
+{
+    const char* errorMessage = NULL;
+
+    OlmInboundGroupSession* sessionPtr = NULL;
+    size_t sessionSize = olm_inbound_group_session_size();
+    jbyte* keyPtr = NULL;
+    jbyte* pickledPtr = NULL;
+
+    LOGD("## deserializeJni(): IN");
+
+    if (!sessionSize)
+    {
+        LOGE(" ## deserializeJni(): failure - inbound group session size = 0");
+        errorMessage = "inbound group session size = 0";
+    }
+    else if (!(sessionPtr = (OlmInboundGroupSession*)malloc(sessionSize)))
+    {
+        LOGE(" ## deserializeJni(): failure - session failure OOM");
+        errorMessage = "session failure OOM";
+    }
+    else if (!aKeyBuffer)
+    {
+        LOGE(" ## deserializeJni(): failure - invalid key");
+        errorMessage = "invalid key";
+    }
+    else if (!aSerializedDataBuffer)
+    {
+        LOGE(" ## deserializeJni(): failure - serialized data");
+        errorMessage = "serialized data";
+    }
+    else if (!(keyPtr = env->GetByteArrayElements(aKeyBuffer, 0)))
+    {
+        LOGE(" ## deserializeJni(): failure - keyPtr JNI allocation OOM");
+        errorMessage = "keyPtr JNI allocation OOM";
+    }
+    else if (!(pickledPtr = env->GetByteArrayElements(aSerializedDataBuffer, 0)))
+    {
+        LOGE(" ## deserializeJni(): failure - pickledPtr JNI allocation OOM");
+        errorMessage = "pickledPtr JNI allocation OOM";
+    }
+    else
+    {
+        sessionPtr = olm_inbound_group_session(sessionPtr);
+
+        size_t pickledLength = (size_t)env->GetArrayLength(aSerializedDataBuffer);
+        size_t keyLength = (size_t)env->GetArrayLength(aKeyBuffer);
+        LOGD(" ## deserializeJni(): pickledLength=%lu keyLength=%lu",static_cast<long unsigned int>(pickledLength), static_cast<long unsigned int>(keyLength));
+        LOGD(" ## deserializeJni(): pickled=%.*s", static_cast<int>(pickledLength), (char const *)pickledPtr);
+
+        size_t result = olm_unpickle_inbound_group_session(sessionPtr,
+                                                           (void const *)keyPtr,
+                                                           keyLength,
+                                                           (void*)pickledPtr,
+                                                           pickledLength);
+        if (result == olm_error())
+        {
+            errorMessage = olm_inbound_group_session_last_error(sessionPtr);
+            LOGE(" ## deserializeJni(): failure - olm_unpickle_inbound_group_session() Msg=%s", errorMessage);
+        }
+        else
+        {
+            LOGD(" ## deserializeJni(): success - result=%lu ", static_cast<long unsigned int>(result));
+        }
+    }
+
+    // free alloc
+    if (keyPtr)
+    {
+        env->ReleaseByteArrayElements(aKeyBuffer, keyPtr, JNI_ABORT);
+    }
+
+    if (pickledPtr)
+    {
+        env->ReleaseByteArrayElements(aSerializedDataBuffer, pickledPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        if (sessionPtr)
+        {
+            olm_clear_inbound_group_session(sessionPtr);
+            free(sessionPtr);
+        }
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return (jlong)(intptr_t)sessionPtr;
+}
diff --git a/android/olm-sdk/src/main/jni/olm_inbound_group_session.h b/android/olm-sdk/src/main/jni/olm_inbound_group_session.h
new file mode 100644
index 0000000..00990dd
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_inbound_group_session.h
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _OMLINBOUND_GROUP_SESSION_H
+#define _OMLINBOUND_GROUP_SESSION_H
+
+#include "olm_jni.h"
+#include "olm/olm.h"
+#include "olm/inbound_group_session.h"
+
+#define OLM_INBOUND_GROUP_SESSION_FUNC_DEF(func_name) FUNC_DEF(OlmInboundGroupSession,func_name)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// session creation/destruction
+JNIEXPORT void OLM_INBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jlong OLM_INBOUND_GROUP_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz, jbyteArray aSessionKeyBuffer);
+
+JNIEXPORT jbyteArray OLM_INBOUND_GROUP_SESSION_FUNC_DEF(sessionIdentifierJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jbyteArray OLM_INBOUND_GROUP_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *env, jobject thiz, jbyteArray aEncryptedMsg, jobject aDecryptIndex);
+
+// serialization
+JNIEXPORT jbyteArray OLM_INBOUND_GROUP_SESSION_FUNC_DEF(serializeJni)(JNIEnv *env, jobject thiz, jbyteArray aKey);
+JNIEXPORT jlong OLM_INBOUND_GROUP_SESSION_FUNC_DEF(deserializeJni)(JNIEnv *env, jobject thiz, jbyteArray aSerializedData, jbyteArray aKey);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/android/olm-sdk/src/main/jni/olm_jni.h b/android/olm-sdk/src/main/jni/olm_jni.h
new file mode 100644
index 0000000..e6a49e2
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_jni.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _OMLJNI_H
+#define _OMLJNI_H
+
+#include <cstdlib>
+#include <cstdio>
+#include <string>
+#include <sstream>
+#include <jni.h>
+#include <android/log.h>
+
+
+#define TAG "OlmJniNative"
+
+/* logging macros */
+//#define ENABLE_JNI_LOG
+
+#ifdef NDK_DEBUG
+    #warning NDK_DEBUG is defined!
+#endif
+
+#ifdef ENABLE_JNI_LOG
+    #warning ENABLE_JNI_LOG is defined!
+#endif
+
+#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, TAG, __VA_ARGS__)
+
+#ifdef ENABLE_JNI_LOG
+    #define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, TAG, __VA_ARGS__)
+    #define LOGW(...) __android_log_print(ANDROID_LOG_WARN, TAG, __VA_ARGS__)
+#else
+    #define LOGD(...)
+    #define LOGW(...)
+#endif
+
+#define FUNC_DEF(class_name,func_name) JNICALL Java_org_matrix_olm_##class_name##_##func_name
+
+namespace AndroidOlmSdk
+{
+
+}
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// internal helper functions
+bool setRandomInBuffer(JNIEnv *env, uint8_t **aBuffer2Ptr, size_t aRandomSize);
+
+struct OlmSession* getSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject);
+struct OlmAccount* getAccountInstanceId(JNIEnv* aJniEnv, jobject aJavaObject);
+struct OlmInboundGroupSession* getInboundGroupSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject);
+struct OlmOutboundGroupSession* getOutboundGroupSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject);
+struct OlmUtility* getUtilityInstanceId(JNIEnv* aJniEnv, jobject aJavaObject);
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif
diff --git a/android/olm-sdk/src/main/jni/olm_jni_helper.cpp b/android/olm-sdk/src/main/jni/olm_jni_helper.cpp
new file mode 100644
index 0000000..a1f5c59
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_jni_helper.cpp
@@ -0,0 +1,214 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "olm_jni_helper.h"
+#include "olm/olm.h"
+#include <sys/time.h>
+
+using namespace AndroidOlmSdk;
+
+/**
+* Init a buffer with a given number of random values.
+* @param aBuffer2Ptr the buffer to be initialized
+* @param aRandomSize the number of random values to apply
+* @return true if operation succeed, false otherwise
+**/
+bool setRandomInBuffer(JNIEnv *env, uint8_t **aBuffer2Ptr, size_t aRandomSize)
+{
+    bool retCode = false;
+    int bufferLen = aRandomSize*sizeof(uint8_t);
+
+    if (!aBuffer2Ptr)
+    {
+        LOGE("## setRandomInBuffer(): failure - aBuffer=NULL");
+    }
+    else if (!aRandomSize)
+    {
+        LOGE("## setRandomInBuffer(): failure - random size=0");
+    }
+    else if (!(*aBuffer2Ptr = (uint8_t*)malloc(bufferLen)))
+    {
+        LOGE("## setRandomInBuffer(): failure - alloc mem OOM");
+    }
+    else
+    {
+        LOGD("## setRandomInBuffer(): randomSize=%lu",static_cast<long unsigned int>(aRandomSize));
+
+        // use the secureRandom class
+        jclass cls = env->FindClass("java/security/SecureRandom");
+
+        if (cls)
+        {
+            jobject newObj = 0;
+            jmethodID constructor = env->GetMethodID(cls, "<init>", "()V");
+            jmethodID nextByteMethod = env->GetMethodID(cls, "nextBytes", "([B)V");
+
+            if (constructor)
+            {
+                newObj = env->NewObject(cls, constructor);
+                jbyteArray tempByteArray = env->NewByteArray(bufferLen);
+
+                if (newObj && tempByteArray)
+                {
+                    env->CallVoidMethod(newObj, nextByteMethod, tempByteArray);
+
+                    if (!env->ExceptionOccurred())
+                    {
+                        jbyte* buffer = env->GetByteArrayElements(tempByteArray, NULL);
+
+                        if (buffer)
+                        {
+                            memcpy(*aBuffer2Ptr, buffer, bufferLen);
+                            retCode = true;
+
+                            // clear tempByteArray to hide sensitive data.
+                            memset(buffer, 0, bufferLen);
+                            env->SetByteArrayRegion(tempByteArray, 0, bufferLen, buffer);
+
+                            // ensure that the buffer is released
+                            env->ReleaseByteArrayElements(tempByteArray, buffer, JNI_ABORT);
+                        }
+                    }
+                }
+
+                if (tempByteArray)
+                {
+                    env->DeleteLocalRef(tempByteArray);
+                }
+
+                if (newObj)
+                {
+                    env->DeleteLocalRef(newObj);
+                }
+            }
+        }
+
+        // debug purpose
+        /*for(int i = 0; i < aRandomSize; i++)
+        {
+            LOGD("## setRandomInBuffer(): randomBuffPtr[%ld]=%d",i, (*aBuffer2Ptr)[i]);
+        }*/
+    }
+
+    return retCode;
+}
+
+/**
+* Read the instance ID of the calling object.
+* @param aJniEnv pointer pointing on the JNI function table
+* @param aJavaObject reference to the object on which the method is invoked
+* @param aCallingClass java calling class name
+* @return the related instance ID
+**/
+jlong getInstanceId(JNIEnv* aJniEnv, jobject aJavaObject, const char *aCallingClass)
+{
+    jlong instanceId = 0;
+
+    if (aJniEnv)
+    {
+        jclass requiredClass = aJniEnv->FindClass(aCallingClass);
+        jclass loaderClass = 0;
+
+        if (requiredClass && (JNI_TRUE != aJniEnv->IsInstanceOf(aJavaObject, requiredClass)))
+        {
+            LOGE("## getInstanceId() failure - invalid instance of");
+        }
+        else if ((loaderClass = aJniEnv->GetObjectClass(aJavaObject)))
+        {
+            jfieldID instanceIdField = aJniEnv->GetFieldID(loaderClass, "mNativeId", "J");
+
+            if (instanceIdField)
+            {
+                instanceId = aJniEnv->GetLongField(aJavaObject, instanceIdField);
+                LOGD("## getInstanceId(): read from java instanceId=%lld",instanceId);
+            }
+            else
+            {
+                LOGE("## getInstanceId() ERROR! GetFieldID=null");
+            }
+
+             aJniEnv->DeleteLocalRef(loaderClass);
+        }
+        else
+        {
+            LOGE("## getInstanceId() ERROR! GetObjectClass=null");
+        }
+    }
+    else
+    {
+        LOGE("## getInstanceId() ERROR! aJniEnv=NULL");
+    }
+
+    LOGD("## getInstanceId() success - instanceId=%p (jlong)(intptr_t)instanceId=%lld",(void*)instanceId, (jlong)(intptr_t)instanceId);
+
+    return instanceId;
+}
+
+/**
+* Read the account instance ID of the calling object.
+* @param aJniEnv pointer pointing on the JNI function table
+* @param aJavaObject reference to the object on which the method is invoked
+* @return the related OlmAccount.
+**/
+struct OlmAccount* getAccountInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
+{
+    return (struct OlmAccount*)getInstanceId(aJniEnv, aJavaObject, CLASS_OLM_ACCOUNT);
+}
+
+/**
+* Read the session instance ID of the calling object (aJavaObject).<br>
+* @param aJniEnv pointer pointing on the JNI function table
+* @param aJavaObject reference to the object on which the method is invoked
+* @return the related OlmSession.
+**/
+struct OlmSession* getSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
+{
+    return (struct OlmSession*)getInstanceId(aJniEnv, aJavaObject, CLASS_OLM_SESSION);
+}
+
+/**
+* Read the inbound group session instance ID of the calling object (aJavaObject).<br>
+* @param aJniEnv pointer pointing on the JNI function table
+* @param aJavaObject reference to the object on which the method is invoked
+* @return the related OlmInboundGroupSession.
+**/
+struct OlmInboundGroupSession* getInboundGroupSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
+{
+    return (struct OlmInboundGroupSession*)getInstanceId(aJniEnv, aJavaObject, CLASS_OLM_INBOUND_GROUP_SESSION);
+}
+
+/**
+* Read the outbound group session instance ID of the calling object (aJavaObject).<br>
+* @param aJniEnv pointer pointing on the JNI function table
+* @param aJavaObject reference to the object on which the method is invoked
+* @return the related OlmOutboundGroupSession
+**/
+struct OlmOutboundGroupSession* getOutboundGroupSessionInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
+{
+    return (struct OlmOutboundGroupSession*)getInstanceId(aJniEnv, aJavaObject, CLASS_OLM_OUTBOUND_GROUP_SESSION);
+}
+
+/**
+* Read the utility instance ID of the calling object (aJavaObject).<br>
+* @param aJniEnv pointer pointing on the JNI function table
+* @param aJavaObject reference to the object on which the method is invoked
+* @return the related OlmUtility
+**/
+struct OlmUtility* getUtilityInstanceId(JNIEnv* aJniEnv, jobject aJavaObject)
+{
+    return (struct OlmUtility*)getInstanceId(aJniEnv, aJavaObject, CLASS_OLM_UTILITY);
+}
diff --git a/android/olm-sdk/src/main/jni/olm_jni_helper.h b/android/olm-sdk/src/main/jni/olm_jni_helper.h
new file mode 100644
index 0000000..a181b32
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_jni_helper.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "olm_jni.h"
+
+// constant strings
+namespace AndroidOlmSdk
+{
+    static const char *CLASS_OLM_INBOUND_GROUP_SESSION = "org/matrix/olm/OlmInboundGroupSession";
+    static const char *CLASS_OLM_OUTBOUND_GROUP_SESSION = "org/matrix/olm/OlmOutboundGroupSession";
+    static const char *CLASS_OLM_SESSION = "org/matrix/olm/OlmSession";
+    static const char *CLASS_OLM_ACCOUNT = "org/matrix/olm/OlmAccount";
+    static const char *CLASS_OLM_UTILITY = "org/matrix/olm/OlmUtility";
+}
diff --git a/android/olm-sdk/src/main/jni/olm_manager.cpp b/android/olm-sdk/src/main/jni/olm_manager.cpp
new file mode 100644
index 0000000..8ee0df7
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_manager.cpp
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "olm_manager.h"
+
+using namespace AndroidOlmSdk;
+
+JNIEXPORT jstring OLM_MANAGER_FUNC_DEF(getOlmLibVersionJni)(JNIEnv* env, jobject thiz)
+{
+    uint8_t majorVer=0, minorVer=0, patchVer=0;
+    jstring returnValueStr=0;
+    char buff[150];
+
+    olm_get_library_version(&majorVer, &minorVer, &patchVer);
+    LOGD("## getOlmLibVersionJni(): Major=%d Minor=%d Patch=%d", majorVer, minorVer, patchVer);
+
+    snprintf(buff, sizeof(buff), "%d.%d.%d", majorVer, minorVer, patchVer);
+    returnValueStr = env->NewStringUTF((const char*)buff);
+
+    return returnValueStr;
+}
\ No newline at end of file
diff --git a/android/olm-sdk/src/main/jni/olm_manager.h b/android/olm-sdk/src/main/jni/olm_manager.h
new file mode 100644
index 0000000..5fb6da2
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_manager.h
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _OMLMANAGER_H
+#define _OMLMANAGER_H
+
+#include "olm_jni.h"
+#include "olm/olm.h"
+
+#define OLM_MANAGER_FUNC_DEF(func_name) FUNC_DEF(OlmManager,func_name)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+JNIEXPORT jstring OLM_MANAGER_FUNC_DEF(getOlmLibVersionJni)(JNIEnv *env, jobject thiz);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/android/olm-sdk/src/main/jni/olm_outbound_group_session.cpp b/android/olm-sdk/src/main/jni/olm_outbound_group_session.cpp
new file mode 100644
index 0000000..a821709
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_outbound_group_session.cpp
@@ -0,0 +1,550 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "olm_outbound_group_session.h"
+
+using namespace AndroidOlmSdk;
+
+/**
+ * Release the session allocation made by initializeOutboundGroupSessionMemory().<br>
+ * This method MUST be called when java counter part account instance is done.
+ *
+ */
+JNIEXPORT void OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env, jobject thiz)
+{
+    LOGD("## releaseSessionJni(): OutBound group session IN");
+
+    OlmOutboundGroupSession* sessionPtr = (OlmOutboundGroupSession*)getOutboundGroupSessionInstanceId(env,thiz);
+
+    if (!sessionPtr)
+    {
+        LOGE(" ## releaseSessionJni(): failure - invalid outbound group session instance");
+    }
+    else
+    {
+        LOGD(" ## releaseSessionJni(): sessionPtr=%p",sessionPtr);
+
+#ifdef ENABLE_JNI_LOG
+        size_t retCode = olm_clear_outbound_group_session(sessionPtr);
+        LOGD(" ## releaseSessionJni(): clear_outbound_group_session=%lu",static_cast<long unsigned int>(retCode));
+#else
+        olm_clear_outbound_group_session(sessionPtr);
+#endif
+
+        LOGD(" ## releaseSessionJni(): free IN");
+        free(sessionPtr);
+        LOGD(" ## releaseSessionJni(): free OUT");
+    }
+}
+
+/**
+ * Initialize a new outbound group session and return it to JAVA side.<br>
+ * Since a C prt is returned as a jlong, special care will be taken
+ * to make the cast (OlmOutboundGroupSession* => jlong) platform independent.
+ * @return the initialized OlmOutboundGroupSession* instance or throw an exception
+ **/
+JNIEXPORT jlong OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz)
+{
+    const char* errorMessage = NULL;
+
+    OlmOutboundGroupSession* sessionPtr = NULL;
+    size_t sessionSize = 0;
+
+    LOGD("## createNewSessionJni(): outbound group session IN");
+    sessionSize = olm_outbound_group_session_size();
+
+    if (0 == sessionSize)
+    {
+        LOGE(" ## createNewSessionJni(): failure - outbound group session size = 0");
+        errorMessage = "outbound group session size = 0";
+    }
+    else if (!(sessionPtr = (OlmOutboundGroupSession*)malloc(sessionSize)))
+    {
+        LOGE(" ## createNewSessionJni(): failure - outbound group session OOM");
+        errorMessage = "outbound group session OOM";
+    }
+    else
+    {
+        sessionPtr = olm_outbound_group_session(sessionPtr);
+        LOGD(" ## createNewSessionJni(): success - outbound group session size=%lu",static_cast<long unsigned int>(sessionSize));
+
+        // compute random buffer
+        size_t randomLength = olm_init_outbound_group_session_random_length(sessionPtr);
+        uint8_t *randomBuffPtr = NULL;
+
+        LOGW(" ## createNewSessionJni(): randomLength=%lu",static_cast<long unsigned int>(randomLength));
+
+        if ((0 != randomLength) && !setRandomInBuffer(env, &randomBuffPtr, randomLength))
+        {
+            LOGE(" ## createNewSessionJni(): failure - random buffer init");
+            errorMessage = "random buffer init";
+        }
+        else
+        {
+            if (0 == randomLength)
+            {
+                LOGW(" ## createNewSessionJni(): random buffer is not required");
+            }
+
+            size_t sessionResult = olm_init_outbound_group_session(sessionPtr, randomBuffPtr, randomLength);
+
+            if (sessionResult == olm_error()) {
+                errorMessage = (const char *)olm_outbound_group_session_last_error(sessionPtr);
+                LOGE(" ## createNewSessionJni(): failure - init outbound session creation  Msg=%s", errorMessage);
+            }
+            else
+            {
+                LOGD(" ## createNewSessionJni(): success - result=%lu", static_cast<long unsigned int>(sessionResult));
+            }
+
+            // clear the random buffer
+            memset(randomBuffPtr, 0, randomLength);
+            free(randomBuffPtr);
+        }
+    }
+
+    if (errorMessage)
+    {
+        if (sessionPtr)
+        {
+            olm_clear_outbound_group_session(sessionPtr);
+            free(sessionPtr);
+        }
+
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return (jlong)(intptr_t)sessionPtr;
+}
+
+/**
+ * Return the session identifier.
+ * An exception is thrown if the operation fails.
+ * @return the session identifier
+ */
+JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(sessionIdentifierJni)(JNIEnv *env, jobject thiz)
+{
+    LOGD("## sessionIdentifierJni(): outbound group session IN");
+
+    const char* errorMessage = NULL;
+    OlmOutboundGroupSession *sessionPtr = (OlmOutboundGroupSession*)getOutboundGroupSessionInstanceId(env,thiz);
+    jbyteArray returnValue = 0;
+    
+    if (!sessionPtr)
+    {
+        LOGE(" ## sessionIdentifierJni(): failure - invalid outbound group session instance");
+        errorMessage = "invalid outbound group session instance";
+    }
+    else
+    {
+        // get the size to alloc
+        size_t lengthSessionId = olm_outbound_group_session_id_length(sessionPtr);
+        LOGD(" ## sessionIdentifierJni(): outbound group session lengthSessionId=%lu",static_cast<long unsigned int>(lengthSessionId));
+
+        uint8_t *sessionIdPtr =  (uint8_t*)malloc(lengthSessionId*sizeof(uint8_t));
+
+        if (!sessionIdPtr)
+        {
+           LOGE(" ## sessionIdentifierJni(): failure - outbound identifier allocation OOM");
+           errorMessage = "outbound identifier allocation OOM";
+        }
+        else
+        {
+            size_t result = olm_outbound_group_session_id(sessionPtr, sessionIdPtr, lengthSessionId);
+
+            if (result == olm_error())
+            {
+                errorMessage = reinterpret_cast<const char*>(olm_outbound_group_session_last_error(sessionPtr));
+                LOGE(" ## sessionIdentifierJni(): failure - outbound group session identifier failure Msg=%s", errorMessage);
+            }
+            else
+            {
+                returnValue = env->NewByteArray(result);
+                env->SetByteArrayRegion(returnValue, 0 , result, (jbyte*)sessionIdPtr);
+
+                LOGD(" ## sessionIdentifierJni(): success - outbound group session identifier result=%lu sessionId= %.*s",static_cast<long unsigned int>(result), static_cast<int>(result), reinterpret_cast<char*>(sessionIdPtr));
+            }
+
+            // free alloc
+            free(sessionIdPtr);
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return returnValue;
+}
+
+
+/**
+ * Get the current message index for this session.<br>
+ * Each message is sent with an increasing index, this
+ * method returns the index for the next message.
+ * An exception is thrown if the operation fails.
+ * @return current session index
+ */
+JNIEXPORT jint OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(messageIndexJni)(JNIEnv *env, jobject thiz)
+{
+    OlmOutboundGroupSession *sessionPtr = NULL;
+    jint indexRetValue = 0;
+
+    LOGD("## messageIndexJni(): IN");
+
+    if (!(sessionPtr = (OlmOutboundGroupSession*)getOutboundGroupSessionInstanceId(env,thiz)))
+    {
+        LOGE(" ## messageIndexJni(): failure - invalid outbound group session instance");
+    }
+    else
+    {
+        indexRetValue = static_cast<jint>(olm_outbound_group_session_message_index(sessionPtr));
+    }
+
+    LOGD(" ## messageIndexJni(): success - index=%d",indexRetValue);
+
+    return indexRetValue;
+}
+
+/**
+ * Return the session key.
+ * An exception is thrown if the operation fails.
+ * @return the session key
+ */
+JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(sessionKeyJni)(JNIEnv *env, jobject thiz)
+{
+    LOGD("## sessionKeyJni(): outbound group session IN");
+
+    const char* errorMessage = NULL;
+    OlmOutboundGroupSession *sessionPtr = (OlmOutboundGroupSession*)getOutboundGroupSessionInstanceId(env,thiz);
+    jbyteArray returnValue = 0;
+
+    if (!sessionPtr)
+    {
+        LOGE(" ## sessionKeyJni(): failure - invalid outbound group session instance");
+        errorMessage = "invalid outbound group session instance";
+    }
+    else
+    {
+        // get the size to alloc
+        size_t sessionKeyLength = olm_outbound_group_session_key_length(sessionPtr);
+        LOGD(" ## sessionKeyJni(): sessionKeyLength=%lu",static_cast<long unsigned int>(sessionKeyLength));
+
+        uint8_t *sessionKeyPtr = (uint8_t*)malloc(sessionKeyLength*sizeof(uint8_t));
+
+        if (!sessionKeyPtr)
+        {
+           LOGE(" ## sessionKeyJni(): failure - session key allocation OOM");
+           errorMessage = "session key allocation OOM";
+        }
+        else
+        {
+            size_t result = olm_outbound_group_session_key(sessionPtr, sessionKeyPtr, sessionKeyLength);
+
+            if (result == olm_error())
+            {
+                errorMessage = (const char *)olm_outbound_group_session_last_error(sessionPtr);
+                LOGE(" ## sessionKeyJni(): failure - session key failure Msg=%s", errorMessage);
+            }
+            else
+            {
+                LOGD(" ## sessionKeyJni(): success - outbound group session key result=%lu sessionKey=%.*s",static_cast<long unsigned int>(result), static_cast<int>(result), reinterpret_cast<char*>(sessionKeyPtr));
+
+                returnValue = env->NewByteArray(result);
+                env->SetByteArrayRegion(returnValue, 0 , result, (jbyte*)sessionKeyPtr);
+            }
+
+            // free alloc
+            free(sessionKeyPtr);
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return returnValue;
+}
+
+/**
+ * Encrypt a bytes buffer messages.
+ * An exception is thrown if the operation fails.
+ * @param aClearMsgBuffer  the message to encode
+ * @return the encoded message
+ */
+JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(encryptMessageJni)(JNIEnv *env, jobject thiz, jbyteArray aClearMsgBuffer)
+{
+    LOGD("## encryptMessageJni(): IN");
+
+    const char* errorMessage = NULL;
+    jbyteArray encryptedMsgRet = 0;
+
+    OlmOutboundGroupSession *sessionPtr = NULL;
+    jbyte* clearMsgPtr = NULL;
+
+    if (!(sessionPtr = (OlmOutboundGroupSession*)getOutboundGroupSessionInstanceId(env,thiz)))
+    {
+        LOGE(" ## encryptMessageJni(): failure - invalid outbound group session ptr=NULL");
+        errorMessage = "invalid outbound group session ptr=NULL";
+    }
+    else if (!aClearMsgBuffer)
+    {
+        LOGE(" ## encryptMessageJni(): failure - invalid clear message");
+        errorMessage = "invalid clear message";
+    }
+    else if (!(clearMsgPtr = env->GetByteArrayElements(aClearMsgBuffer, NULL)))
+    {
+        LOGE(" ## encryptMessageJni(): failure - clear message JNI allocation OOM");
+        errorMessage = "clear message JNI allocation OOM";
+    }
+    else
+    {
+        // get clear message length
+        size_t clearMsgLength = (size_t)env->GetArrayLength(aClearMsgBuffer);
+        LOGD(" ## encryptMessageJni(): clearMsgLength=%lu",static_cast<long unsigned int>(clearMsgLength));
+
+        // compute max encrypted length
+        size_t encryptedMsgLength = olm_group_encrypt_message_length(sessionPtr,clearMsgLength);
+        uint8_t *encryptedMsgPtr = (uint8_t*)malloc(encryptedMsgLength*sizeof(uint8_t));
+
+        if (!encryptedMsgPtr)
+        {
+            LOGE(" ## encryptMessageJni(): failure - encryptedMsgPtr buffer OOM");
+            errorMessage = "encryptedMsgPtr buffer OOM";
+        }
+        else
+        {
+            LOGD(" ## encryptMessageJni(): estimated encryptedMsgLength=%lu",static_cast<long unsigned int>(encryptedMsgLength));
+
+            size_t encryptedLength = olm_group_encrypt(sessionPtr,
+                                                       (uint8_t*)clearMsgPtr,
+                                                       clearMsgLength,
+                                                       encryptedMsgPtr,
+                                                       encryptedMsgLength);
+
+
+            if (encryptedLength == olm_error())
+            {
+                errorMessage = olm_outbound_group_session_last_error(sessionPtr);
+                LOGE(" ## encryptMessageJni(): failure - olm_group_decrypt_max_plaintext_length Msg=%s", errorMessage);
+            }
+            else
+            {
+                LOGD(" ## encryptMessageJni(): encrypted returnedLg=%lu plainTextMsgPtr=%.*s",static_cast<long unsigned int>(encryptedLength), static_cast<int>(encryptedLength), reinterpret_cast<char*>(encryptedMsgPtr));
+
+                encryptedMsgRet = env->NewByteArray(encryptedLength);
+                env->SetByteArrayRegion(encryptedMsgRet, 0 , encryptedLength, (jbyte*)encryptedMsgPtr);
+            }
+
+            free(encryptedMsgPtr);
+         }
+    }
+
+    // free alloc
+    if (clearMsgPtr)
+    {
+        env->ReleaseByteArrayElements(aClearMsgBuffer, clearMsgPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return encryptedMsgRet;
+}
+
+/**
+ * Serialize and encrypt session instance into a base64 string.<br>
+ * An exception is thrown if the operation fails.
+ * @param aKey key used to encrypt the serialized session data
+ * @return a base64 string if operation succeed, null otherwise
+ **/
+JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(serializeJni)(JNIEnv *env, jobject thiz, jbyteArray aKeyBuffer)
+{
+    const char* errorMessage = NULL;
+    jbyteArray returnValue = 0;
+
+    jbyte* keyPtr = NULL;
+    OlmOutboundGroupSession* sessionPtr = NULL;
+
+    LOGD("## outbound group session serializeJni(): IN");
+
+    if (!(sessionPtr = (OlmOutboundGroupSession*)getOutboundGroupSessionInstanceId(env,thiz)))
+    {
+        LOGE(" ## serializeJni(): failure - invalid session ptr");
+        errorMessage = "invalid session ptr";
+    }
+    else if (!aKeyBuffer)
+    {
+        LOGE(" ## serializeJni(): failure - invalid key");
+        errorMessage = "invalid key";
+    }
+    else if (!(keyPtr = env->GetByteArrayElements(aKeyBuffer, 0)))
+    {
+        LOGE(" ## serializeJni(): failure - keyPtr JNI allocation OOM");
+        errorMessage = "keyPtr JNI allocation OOM";
+    }
+    else
+    {
+        size_t pickledLength = olm_pickle_outbound_group_session_length(sessionPtr);
+        size_t keyLength = (size_t)env->GetArrayLength(aKeyBuffer);
+        LOGD(" ## serializeJni(): pickledLength=%lu keyLength=%lu",static_cast<long unsigned int>(pickledLength), static_cast<long unsigned int>(keyLength));
+
+        void *pickledPtr = malloc(pickledLength*sizeof(uint8_t));
+
+        if(!pickledPtr)
+        {
+            LOGE(" ## serializeJni(): failure - pickledPtr buffer OOM");
+            errorMessage = "pickledPtr buffer OOM";
+        }
+        else
+        {
+            size_t result = olm_pickle_outbound_group_session(sessionPtr,
+                                                             (void const *)keyPtr,
+                                                              keyLength,
+                                                              (void*)pickledPtr,
+                                                              pickledLength);
+            if (result == olm_error())
+            {
+                errorMessage = olm_outbound_group_session_last_error(sessionPtr);
+                LOGE(" ## serializeJni(): failure - olm_pickle_outbound_group_session() Msg=%s", errorMessage);
+            }
+            else
+            {
+                LOGD(" ## serializeJni(): success - result=%lu pickled=%.*s", static_cast<long unsigned int>(result), static_cast<int>(result), static_cast<char*>(pickledPtr));
+
+                returnValue = env->NewByteArray(pickledLength);
+                env->SetByteArrayRegion(returnValue, 0 , pickledLength, (jbyte*)pickledPtr);
+            }
+        }
+
+        free(pickledPtr);
+    }
+
+    // free alloc
+    if (keyPtr)
+    {
+        env->ReleaseByteArrayElements(aKeyBuffer, keyPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return returnValue;
+}
+
+/**
+ * Allocate a new session and initialize it with the serialisation data.<br>
+ * An exception is thrown if the operation fails.
+ * @param aSerializedData the session serialisation buffer
+ * @param aKey the key used to encrypt the serialized account data
+ * @return the deserialized session
+ **/
+JNIEXPORT jlong OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(deserializeJni)(JNIEnv *env, jobject thiz, jbyteArray aSerializedDataBuffer, jbyteArray aKeyBuffer)
+{
+    const char* errorMessage = NULL;
+    size_t sessionSize = olm_outbound_group_session_size();
+    OlmOutboundGroupSession* sessionPtr = NULL;
+
+    jbyte* keyPtr = NULL;
+    jbyte* pickledPtr = NULL;
+
+    LOGD("## deserializeJni(): IN");
+
+    if (!sessionSize)
+    {
+        LOGE(" ## deserializeJni(): failure - outbound group session size = 0");
+        errorMessage = "outbound group session size = 0";
+    }
+    else if (!(sessionPtr = (OlmOutboundGroupSession*)malloc(sessionSize)))
+    {
+        LOGE(" ## deserializeJni(): failure - session failure OOM");
+        errorMessage = "session failure OOM";
+    }
+    else if (!aKeyBuffer)
+    {
+        LOGE(" ## deserializeJni(): failure - invalid key");
+        errorMessage = "invalid key";
+    }
+    else if (!aSerializedDataBuffer)
+    {
+        LOGE(" ## deserializeJni(): failure - serialized data");
+        errorMessage = "invalid serialized data";
+    }
+    else if (!(keyPtr = env->GetByteArrayElements(aKeyBuffer, 0)))
+    {
+        LOGE(" ## deserializeJni(): failure - keyPtr JNI allocation OOM");
+        errorMessage = "keyPtr JNI allocation OOM";
+    }
+    else if (!(pickledPtr = env->GetByteArrayElements(aSerializedDataBuffer, 0)))
+    {
+        LOGE(" ## deserializeJni(): failure - pickledPtr JNI allocation OOM");
+        errorMessage = "pickledPtr JNI allocation OOM";
+    }
+    else
+    {
+        sessionPtr = olm_outbound_group_session(sessionPtr);
+        size_t pickledLength = (size_t)env->GetArrayLength(aSerializedDataBuffer);
+        size_t keyLength = (size_t)env->GetArrayLength(aKeyBuffer);
+        LOGD(" ## deserializeJni(): pickledLength=%lu keyLength=%lu",static_cast<long unsigned int>(pickledLength), static_cast<long unsigned int>(keyLength));
+        LOGD(" ## deserializeJni(): pickled=%.*s", static_cast<int>(pickledLength), (char const *)pickledPtr);
+
+        size_t result = olm_unpickle_outbound_group_session(sessionPtr,
+                                                            (void const *)keyPtr,
+                                                            keyLength,
+                                                            (void*)pickledPtr,
+                                                            pickledLength);
+        if (result == olm_error())
+        {
+            errorMessage = olm_outbound_group_session_last_error(sessionPtr);
+            LOGE(" ## deserializeJni(): failure - olm_unpickle_outbound_group_session() Msg=%s", errorMessage);
+        }
+        else
+        {
+            LOGD(" ## deserializeJni(): success - result=%lu ", static_cast<long unsigned int>(result));
+        }
+    }
+
+    // free alloc
+    if (keyPtr)
+    {
+        env->ReleaseByteArrayElements(aKeyBuffer, keyPtr, JNI_ABORT);
+    }
+
+    if (pickledPtr)
+    {
+        env->ReleaseByteArrayElements(aSerializedDataBuffer, pickledPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        if (sessionPtr)
+        {
+            olm_clear_outbound_group_session(sessionPtr);
+            free(sessionPtr);
+        }
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return (jlong)(intptr_t)sessionPtr;
+}
+
diff --git a/android/olm-sdk/src/main/jni/olm_outbound_group_session.h b/android/olm-sdk/src/main/jni/olm_outbound_group_session.h
new file mode 100644
index 0000000..f6abba2
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_outbound_group_session.h
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _OMLOUTBOUND_GROUP_SESSION_H
+#define _OMLOUTBOUND_GROUP_SESSION_H
+
+#include "olm_jni.h"
+#include "olm/olm.h"
+#include "olm/outbound_group_session.h"
+
+#define OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(func_name) FUNC_DEF(OlmOutboundGroupSession,func_name)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// session creation/destruction
+JNIEXPORT void OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jlong OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz);
+
+JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(sessionIdentifierJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jint OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(messageIndexJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(sessionKeyJni)(JNIEnv *env, jobject thiz);
+
+JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(encryptMessageJni)(JNIEnv *env, jobject thiz, jbyteArray aClearMsgBuffer);
+
+// serialization
+JNIEXPORT jbyteArray OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(serializeJni)(JNIEnv *env, jobject thiz, jbyteArray aKey);
+JNIEXPORT jlong OLM_OUTBOUND_GROUP_SESSION_FUNC_DEF(deserializeJni)(JNIEnv *env, jobject thiz, jbyteArray aSerializedData, jbyteArray aKey);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/android/olm-sdk/src/main/jni/olm_session.cpp b/android/olm-sdk/src/main/jni/olm_session.cpp
new file mode 100644
index 0000000..5ca49db
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_session.cpp
@@ -0,0 +1,961 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "olm_session.h"
+
+using namespace AndroidOlmSdk;
+
+/**
+* Init memory allocation for a session creation.<br>
+* Make sure releaseSessionJni() is called when one is done with the session instance.
+* @return valid memory allocation, NULL otherwise
+**/
+OlmSession* initializeSessionMemory()
+{
+    size_t sessionSize = olm_session_size();
+    OlmSession* sessionPtr = (OlmSession*)malloc(sessionSize);
+
+    if (sessionPtr)
+    {
+        // init session object
+        sessionPtr = olm_session(sessionPtr);
+        LOGD("## initializeSessionMemory(): success - OLM session size=%lu",static_cast<long unsigned int>(sessionSize));
+    }
+    else
+    {
+        LOGE("## initializeSessionMemory(): failure - OOM");
+    }
+
+    return sessionPtr;
+}
+
+JNIEXPORT jlong OLM_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz)
+{
+    LOGD("## createNewSessionJni(): IN");
+    OlmSession* accountPtr = initializeSessionMemory();
+
+    if (!accountPtr)
+    {
+        LOGE("## initNewAccount(): failure - init session OOM");
+        env->ThrowNew(env->FindClass("java/lang/Exception"), "init session OOM");
+    }
+    else
+    {
+        LOGD(" ## createNewSessionJni(): success - accountPtr=%p (jlong)(intptr_t)accountPtr=%lld",accountPtr,(jlong)(intptr_t)accountPtr);
+    }
+
+    return (jlong)(intptr_t)accountPtr;
+}
+
+JNIEXPORT void OLM_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env, jobject thiz)
+{
+    LOGD("## releaseSessionJni(): IN");
+    OlmSession* sessionPtr = getSessionInstanceId(env, thiz);
+
+    if (!sessionPtr)
+    {
+        LOGE("## releaseSessionJni(): failure - invalid Session ptr=NULL");
+    }
+    else
+    {
+        olm_clear_session(sessionPtr);
+
+        // even if free(NULL) does not crash, logs are performed for debug purpose
+        free(sessionPtr);
+    }
+}
+
+// *********************************************************************
+// ********************** OUTBOUND SESSION *****************************
+// *********************************************************************
+/**
+ * Create a new in-bound session for sending/receiving messages from an
+ * incoming PRE_KEY message.<br> The recipient is defined as the entity
+ * with whom the session is established.
+ * @param aOlmAccountId account instance
+ * @param aTheirIdentityKey the identity key of the recipient
+ * @param aTheirOneTimeKey the one time key of the recipient or an exception is thrown
+ **/
+JNIEXPORT void OLM_SESSION_FUNC_DEF(initOutboundSessionJni)(JNIEnv *env, jobject thiz, jlong aOlmAccountId, jbyteArray aTheirIdentityKeyBuffer, jbyteArray aTheirOneTimeKeyBuffer)
+{
+    OlmSession* sessionPtr = getSessionInstanceId(env, thiz);
+    const char* errorMessage = NULL;
+    OlmAccount* accountPtr = NULL;
+
+    if (!sessionPtr)
+    {
+        LOGE("## initOutboundSessionJni(): failure - invalid Session ptr=NULL");
+        errorMessage = "invalid Session ptr=NULL";
+    }
+    else if (!(accountPtr = (OlmAccount*)aOlmAccountId))
+    {
+        LOGE("## initOutboundSessionJni(): failure - invalid Account ptr=NULL");
+        errorMessage = "invalid Account ptr=NULL";
+    }
+    else if (!aTheirIdentityKeyBuffer || !aTheirOneTimeKeyBuffer)
+    {
+        LOGE("## initOutboundSessionJni(): failure - invalid keys");
+        errorMessage = "invalid keys";
+    }
+    else
+    {
+        size_t randomSize = olm_create_outbound_session_random_length(sessionPtr);
+        uint8_t *randomBuffPtr = NULL;
+
+        LOGD("## initOutboundSessionJni(): randomSize=%lu",static_cast<long unsigned int>(randomSize));
+
+        if ( (0 != randomSize) && !setRandomInBuffer(env, &randomBuffPtr, randomSize))
+        {
+            LOGE("## initOutboundSessionJni(): failure - random buffer init");
+            errorMessage = "random buffer init";
+        }
+        else
+        {
+            jbyte* theirIdentityKeyPtr = NULL;
+            jbyte* theirOneTimeKeyPtr = NULL;
+
+            // convert identity & one time keys to C strings
+            if (!(theirIdentityKeyPtr = env->GetByteArrayElements(aTheirIdentityKeyBuffer, 0)))
+            {
+                LOGE("## initOutboundSessionJni(): failure - identityKey JNI allocation OOM");
+                errorMessage = "identityKey JNI allocation OOM";
+            }
+            else if (!(theirOneTimeKeyPtr = env->GetByteArrayElements(aTheirOneTimeKeyBuffer, 0)))
+            {
+                LOGE("## initOutboundSessionJni(): failure - one time Key JNI allocation OOM");
+                errorMessage = "one time Key JNI allocation OOM";
+            }
+            else
+            {
+                size_t theirIdentityKeyLength = (size_t)env->GetArrayLength(aTheirIdentityKeyBuffer);
+                size_t theirOneTimeKeyLength  = (size_t)env->GetArrayLength(aTheirOneTimeKeyBuffer);
+                LOGD("## initOutboundSessionJni(): identityKey=%.*s oneTimeKey=%.*s", static_cast<int>(theirIdentityKeyLength), theirIdentityKeyPtr, static_cast<int>(theirOneTimeKeyLength), theirOneTimeKeyPtr);
+
+                size_t sessionResult = olm_create_outbound_session(sessionPtr,
+                                                            accountPtr,
+                                                            theirIdentityKeyPtr,
+                                                            theirIdentityKeyLength,
+                                                            theirOneTimeKeyPtr,
+                                                            theirOneTimeKeyLength,
+                                                            (void*)randomBuffPtr,
+                                                            randomSize);
+                if (sessionResult == olm_error()) {
+                    errorMessage = (const char *)olm_session_last_error(sessionPtr);
+                    LOGE("## initOutboundSessionJni(): failure - session creation  Msg=%s", errorMessage);
+                }
+                else
+                {
+                    LOGD("## initOutboundSessionJni(): success - result=%lu", static_cast<long unsigned int>(sessionResult));
+                }
+            }
+
+            if (theirIdentityKeyPtr)
+            {
+                env->ReleaseByteArrayElements(aTheirIdentityKeyBuffer, theirIdentityKeyPtr, JNI_ABORT);
+            }
+
+            if (theirOneTimeKeyPtr)
+            {
+                env->ReleaseByteArrayElements(aTheirOneTimeKeyBuffer, theirOneTimeKeyPtr, JNI_ABORT);
+            }
+
+            if (randomBuffPtr)
+            {
+                memset(randomBuffPtr, 0, randomSize);
+                free(randomBuffPtr);
+            }
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+}
+
+
+// *********************************************************************
+// *********************** INBOUND SESSION *****************************
+// *********************************************************************
+/**
+ * Create a new in-bound session for sending/receiving messages from an
+ * incoming PRE_KEY message.<br>
+ * An exception is thrown if the operation fails.
+ * @param aOlmAccountId account instance
+ * @param aOneTimeKeyMsg PRE_KEY message
+ */
+JNIEXPORT void OLM_SESSION_FUNC_DEF(initInboundSessionJni)(JNIEnv *env, jobject thiz, jlong aOlmAccountId, jbyteArray aOneTimeKeyMsgBuffer)
+{
+    const char* errorMessage = NULL;
+    OlmSession *sessionPtr = getSessionInstanceId(env,thiz);
+    OlmAccount *accountPtr = NULL;
+    size_t sessionResult;
+
+    if (!sessionPtr)
+    {
+        LOGE("## initInboundSessionJni(): failure - invalid Session ptr=NULL");
+        errorMessage = "invalid Session ptr=NULL";
+    }
+    else if (!(accountPtr = (OlmAccount*)aOlmAccountId))
+    {
+        LOGE("## initInboundSessionJni(): failure - invalid Account ptr=NULL");
+        errorMessage = "invalid Account ptr=NULL";
+    }
+    else if (!aOneTimeKeyMsgBuffer)
+    {
+        LOGE("## initInboundSessionJni(): failure - invalid message");
+        errorMessage = "invalid message";
+    }
+    else
+    {
+        jbyte* messagePtr = env->GetByteArrayElements(aOneTimeKeyMsgBuffer, 0);
+
+        if (!messagePtr)
+        {
+            LOGE("## initInboundSessionJni(): failure - message JNI allocation OOM");
+            errorMessage = "message JNI allocation OOM";
+        }
+        else
+        {
+            size_t messageLength = (size_t)env->GetArrayLength(aOneTimeKeyMsgBuffer);
+            LOGD("## initInboundSessionJni(): messageLength=%lu message=%.*s", static_cast<long unsigned int>(messageLength), static_cast<int>(messageLength), messagePtr);
+
+            sessionResult = olm_create_inbound_session(sessionPtr, accountPtr, (void*)messagePtr , messageLength);
+
+            if (sessionResult == olm_error())
+            {
+                errorMessage = olm_session_last_error(sessionPtr);
+                LOGE("## initInboundSessionJni(): failure - init inbound session creation  Msg=%s", errorMessage);
+            }
+            else
+            {
+                LOGD("## initInboundSessionJni(): success - result=%lu", static_cast<long unsigned int>(sessionResult));
+            }
+
+            // free local alloc
+            env->ReleaseByteArrayElements(aOneTimeKeyMsgBuffer, messagePtr, JNI_ABORT);
+        }
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+}
+
+/**
+ * Create a new in-bound session for sending/receiving messages from an
+ * incoming PRE_KEY message based on the recipient identity key.<br>
+ * An exception is thrown if the operation fails.
+ * @param aOlmAccountId account instance
+ * @param aTheirIdentityKey the identity key of the recipient
+ * @param aOneTimeKeyMsg encrypted message
+ */
+JNIEXPORT void OLM_SESSION_FUNC_DEF(initInboundSessionFromIdKeyJni)(JNIEnv *env, jobject thiz, jlong aOlmAccountId, jbyteArray aTheirIdentityKeyBuffer, jbyteArray aOneTimeKeyMsgBuffer)
+{
+    const char* errorMessage = NULL;
+
+    OlmSession *sessionPtr = getSessionInstanceId(env, thiz);
+    OlmAccount *accountPtr = NULL;
+    jbyte *messagePtr = NULL;
+    jbyte *theirIdentityKeyPtr = NULL;
+    size_t sessionResult;
+
+    if (!sessionPtr)
+    {
+        LOGE("## initInboundSessionFromIdKeyJni(): failure - invalid Session ptr=NULL");
+        errorMessage = "invalid Session ptr=NULL";
+    }
+    else if (!(accountPtr = (OlmAccount*)aOlmAccountId))
+    {
+        LOGE("## initInboundSessionFromIdKeyJni(): failure - invalid Account ptr=NULL");
+        errorMessage = "invalid Account ptr=NULL";
+    }
+    else if (!aTheirIdentityKeyBuffer)
+    {
+        LOGE("## initInboundSessionFromIdKeyJni(): failure - invalid theirIdentityKey");
+        errorMessage = "invalid theirIdentityKey";
+    }
+    else if (!aOneTimeKeyMsgBuffer)
+    {
+        LOGE("## initInboundSessionJni(): failure - invalid one time key message");
+        errorMessage = "invalid invalid one time key message";
+    }
+    else if (!(messagePtr = env->GetByteArrayElements(aOneTimeKeyMsgBuffer, 0)))
+    {
+        LOGE("## initInboundSessionFromIdKeyJni(): failure - message JNI allocation OOM");
+        errorMessage = "message JNI allocation OOM";
+    }
+    else if(!(theirIdentityKeyPtr = env->GetByteArrayElements(aTheirIdentityKeyBuffer, 0)))
+    {
+        LOGE("## initInboundSessionFromIdKeyJni(): failure - theirIdentityKey JNI allocation OOM");
+        errorMessage = "theirIdentityKey JNI allocation OOM";
+    }
+    else
+    {
+        size_t messageLength = (size_t)env->GetArrayLength(aOneTimeKeyMsgBuffer);
+        size_t theirIdentityKeyLength = (size_t)env->GetArrayLength(aTheirIdentityKeyBuffer);
+
+        LOGD("## initInboundSessionFromIdKeyJni(): message=%.*s messageLength=%lu", static_cast<int>(messageLength), messagePtr, static_cast<long unsigned int>(messageLength));
+
+        sessionResult = olm_create_inbound_session_from(sessionPtr, accountPtr, theirIdentityKeyPtr, theirIdentityKeyLength, (void*)messagePtr , messageLength);
+        if (sessionResult == olm_error())
+        {
+            errorMessage = (const char *)olm_session_last_error(sessionPtr);
+            LOGE("## initInboundSessionFromIdKeyJni(): failure - init inbound session creation  Msg=%s", errorMessage);
+        }
+        else
+        {
+            LOGD("## initInboundSessionFromIdKeyJni(): success - result=%lu", static_cast<long unsigned int>(sessionResult));
+        }
+     }
+
+     // free local alloc
+     if (messagePtr)
+     {
+        env->ReleaseByteArrayElements(aOneTimeKeyMsgBuffer, messagePtr, JNI_ABORT);
+     }
+
+     if (theirIdentityKeyPtr)
+     {
+        env->ReleaseByteArrayElements(aTheirIdentityKeyBuffer, theirIdentityKeyPtr, JNI_ABORT);
+     }
+
+     if (errorMessage)
+     {
+         env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+     }
+}
+
+/**
+ * Checks if the PRE_KEY message is for this in-bound session.<br>
+ * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+ * @param aOneTimeKeyMsg PRE KEY message
+ * @return true if the PRE_KEY message matches
+ */
+JNIEXPORT jboolean OLM_SESSION_FUNC_DEF(matchesInboundSessionJni)(JNIEnv *env, jobject thiz, jbyteArray aOneTimeKeyMsgBuffer)
+{
+    jboolean retCode = JNI_FALSE;
+    OlmSession *sessionPtr = getSessionInstanceId(env, thiz);
+    jbyte *messagePtr = NULL;
+
+    if (!sessionPtr)
+    {
+        LOGE("## matchesInboundSessionJni(): failure - invalid Session ptr=NULL");
+    }
+    else if (!aOneTimeKeyMsgBuffer)
+    {
+        LOGE("## matchesInboundSessionJni(): failure - invalid one time key message");
+    }
+    else if (!(messagePtr = env->GetByteArrayElements(aOneTimeKeyMsgBuffer, 0)))
+    {
+        LOGE("## matchesInboundSessionJni(): failure - one time key JNI allocation OOM");
+    }
+    else
+    {
+        size_t messageLength = (size_t)env->GetArrayLength(aOneTimeKeyMsgBuffer);
+
+        size_t matchResult = olm_matches_inbound_session(sessionPtr, (void*)messagePtr , messageLength);
+        //if(matchResult == olm_error()) {
+        // for now olm_matches_inbound_session() returns 1 when it succeeds, otherwise 1- or 0
+        if (matchResult != 1) {
+            LOGE("## matchesInboundSessionJni(): failure - no match  Msg=%s",(const char *)olm_session_last_error(sessionPtr));
+        }
+        else
+        {
+            retCode = JNI_TRUE;
+            LOGD("## matchesInboundSessionJni(): success - result=%lu", static_cast<long unsigned int>(matchResult));
+        }
+    }
+
+    // free local alloc
+    if (messagePtr)
+    {
+        env->ReleaseByteArrayElements(aOneTimeKeyMsgBuffer, messagePtr, JNI_ABORT);
+    }
+
+    return retCode;
+}
+
+/**
+ * Checks if the PRE_KEY message is for this in-bound session based on the sender identity key.<br>
+ * This API may be used to process a "m.room.encrypted" event when type = 1 (PRE_KEY).
+ * @param aTheirIdentityKey the identity key of the sender
+ * @param aOneTimeKeyMsg PRE KEY message
+ * @return true if the PRE_KEY message matches.
+ */
+JNIEXPORT jboolean JNICALL OLM_SESSION_FUNC_DEF(matchesInboundSessionFromIdKeyJni)(JNIEnv *env, jobject thiz, jbyteArray aTheirIdentityKeyBuffer, jbyteArray aOneTimeKeyMsgBuffer)
+{
+    jboolean retCode = JNI_FALSE;
+    OlmSession *sessionPtr = getSessionInstanceId(env, thiz);
+    jbyte *messagePtr = NULL;
+    jbyte *theirIdentityKeyPtr = NULL;
+
+    if (!sessionPtr)
+    {
+        LOGE("## matchesInboundSessionFromIdKeyJni(): failure - invalid Session ptr=NULL");
+    }
+    else if (!aTheirIdentityKeyBuffer)
+    {
+        LOGE("## matchesInboundSessionFromIdKeyJni(): failure - invalid theirIdentityKey");
+    }
+    else if (!(theirIdentityKeyPtr = env->GetByteArrayElements(aTheirIdentityKeyBuffer, 0)))
+    {
+        LOGE("## matchesInboundSessionFromIdKeyJni(): failure - theirIdentityKey JNI allocation OOM");
+    }
+    else if (!aOneTimeKeyMsgBuffer)
+    {
+        LOGE("## matchesInboundSessionFromIdKeyJni(): failure - invalid one time key message");
+    }
+    else if (!(messagePtr = env->GetByteArrayElements(aOneTimeKeyMsgBuffer, 0)))
+    {
+        LOGE("## matchesInboundSessionFromIdKeyJni(): failure - one time key JNI allocation OOM");
+    }
+    else
+    {
+        size_t identityKeyLength = (size_t)env->GetArrayLength(aTheirIdentityKeyBuffer);
+        size_t messageLength = (size_t)env->GetArrayLength(aOneTimeKeyMsgBuffer);
+        size_t matchResult = olm_matches_inbound_session_from(sessionPtr, (void const *)theirIdentityKeyPtr, identityKeyLength, (void*)messagePtr , messageLength);
+
+        //if(matchResult == olm_error()) {
+        // for now olm_matches_inbound_session() returns 1 when it succeeds, otherwise 1- or 0
+        if (matchResult != 1)
+        {
+            LOGE("## matchesInboundSessionFromIdKeyJni(): failure - no match  Msg=%s",(const char *)olm_session_last_error(sessionPtr));
+        }
+        else
+        {
+            retCode = JNI_TRUE;
+            LOGD("## matchesInboundSessionFromIdKeyJni(): success - result=%lu", static_cast<long unsigned int>(matchResult));
+        }
+    }
+
+    // free local alloc
+    if (theirIdentityKeyPtr)
+    {
+        env->ReleaseByteArrayElements(aTheirIdentityKeyBuffer, theirIdentityKeyPtr, JNI_ABORT);
+    }
+
+    if (messagePtr)
+    {
+        env->ReleaseByteArrayElements(aOneTimeKeyMsgBuffer, messagePtr, JNI_ABORT);
+    }
+
+    return retCode;
+}
+
+/**
+ * Encrypt a message using the session.<br>
+ * An exception is thrown if the operation fails.
+ * @param aClearMsg clear text message
+ * @param [out] aEncryptedMsg ciphered message
+ * @return the encrypted message
+ */
+JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(encryptMessageJni)(JNIEnv *env, jobject thiz, jbyteArray aClearMsgBuffer, jobject aEncryptedMsg)
+{
+    jbyteArray encryptedMsgRet = 0;
+    const char* errorMessage = NULL;
+
+    OlmSession *sessionPtr = getSessionInstanceId(env, thiz);
+    jbyte *clearMsgPtr = NULL;
+    jclass encryptedMsgJClass = 0;
+    jfieldID typeMsgFieldId;
+
+    LOGD("## encryptMessageJni(): IN ");
+
+    if (!sessionPtr)
+    {
+        LOGE("## encryptMessageJni(): failure - invalid Session ptr=NULL");
+        errorMessage = "invalid Session ptr=NULL";
+    }
+    else if (!aClearMsgBuffer)
+    {
+        LOGE("## encryptMessageJni(): failure - invalid clear message");
+        errorMessage = "invalid clear message";
+    }
+    else if (!aEncryptedMsg)
+    {
+        LOGE("## encryptMessageJni(): failure - invalid encrypted message");
+    }
+    else if (!(clearMsgPtr = env->GetByteArrayElements(aClearMsgBuffer, 0)))
+    {
+        LOGE("## encryptMessageJni(): failure - clear message JNI allocation OOM");
+        errorMessage = "clear message JNI allocation OOM";
+    }
+    else if (!(encryptedMsgJClass = env->GetObjectClass(aEncryptedMsg)))
+    {
+        LOGE("## encryptMessageJni(): failure - unable to get crypted message class");
+        errorMessage = "unable to get crypted message class";
+    }
+    else if (!(typeMsgFieldId = env->GetFieldID(encryptedMsgJClass,"mType","J")))
+    {
+        LOGE("## encryptMessageJni(): failure - unable to get message type field");
+        errorMessage = "unable to get message type field";
+    }
+    else
+    {
+        // get message type
+        size_t messageType = olm_encrypt_message_type(sessionPtr);
+        uint8_t *randomBuffPtr = NULL;
+
+        // compute random buffer
+        // Note: olm_encrypt_random_length() can return 0, which means
+        // it just does not need new random data to encrypt a new message
+        size_t randomLength = olm_encrypt_random_length(sessionPtr);
+
+        LOGD("## encryptMessageJni(): randomLength=%lu", static_cast<long unsigned int>(randomLength));
+
+        if ((0 != randomLength) && !setRandomInBuffer(env, &randomBuffPtr, randomLength))
+        {
+            LOGE("## encryptMessageJni(): failure - random buffer init");
+            errorMessage = "random buffer init";
+        }
+        else
+        {
+            // alloc buffer for encrypted message
+            size_t clearMsgLength = (size_t)env->GetArrayLength(aClearMsgBuffer);
+            size_t encryptedMsgLength = olm_encrypt_message_length(sessionPtr, clearMsgLength);
+
+            void *encryptedMsgPtr = malloc(encryptedMsgLength*sizeof(uint8_t));
+
+            if (!encryptedMsgPtr)
+            {
+                LOGE("## encryptMessageJni(): failure - encryptedMsgPtr buffer OOM");
+                errorMessage = "encryptedMsgPtr buffer OOM";
+            }
+            else
+            {
+                if (0 == randomLength)
+                {
+                    LOGW("## encryptMessageJni(): random buffer is not required");
+                }
+
+                LOGD("## encryptMessageJni(): messageType=%lu randomLength=%lu clearMsgLength=%lu encryptedMsgLength=%lu",static_cast<long unsigned int>(messageType),static_cast<long unsigned int>(randomLength), static_cast<long unsigned int>(clearMsgLength), static_cast<long unsigned int>(encryptedMsgLength));
+                // encrypt message
+                size_t result = olm_encrypt(sessionPtr,
+                                            (void const *)clearMsgPtr,
+                                            clearMsgLength,
+                                            randomBuffPtr,
+                                            randomLength,
+                                            encryptedMsgPtr,
+                                            encryptedMsgLength);
+                if (result == olm_error())
+                {
+                    errorMessage = (const char *)olm_session_last_error(sessionPtr);
+                    LOGE("## encryptMessageJni(): failure - Msg=%s", errorMessage);
+                }
+                else
+                {
+                    // update message type: PRE KEY or normal
+                    env->SetLongField(aEncryptedMsg, typeMsgFieldId, (jlong)messageType);
+
+                    encryptedMsgRet = env->NewByteArray(encryptedMsgLength);
+                    env->SetByteArrayRegion(encryptedMsgRet, 0 , encryptedMsgLength, (jbyte*)encryptedMsgPtr);
+
+                    LOGD("## encryptMessageJni(): success - result=%lu Type=%lu encryptedMsg=%.*s", static_cast<long unsigned int>(result), static_cast<unsigned long int>(messageType), static_cast<int>(result), (const char*)encryptedMsgPtr);
+                }
+
+                free(encryptedMsgPtr);
+            }
+
+            memset(randomBuffPtr, 0, randomLength);
+            free(randomBuffPtr);
+        }
+    }
+
+    // free alloc
+    if (clearMsgPtr)
+    {
+        env->ReleaseByteArrayElements(aClearMsgBuffer, clearMsgPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return encryptedMsgRet;
+}
+
+/**
+ * Decrypt a message using the session.<br>
+ * An exception is thrown if the operation fails.
+ * @param aEncryptedMsg message to decrypt
+ * @return decrypted message if operation succeed
+ */
+JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *env, jobject thiz, jobject aEncryptedMsg)
+{
+    const char* errorMessage = NULL;
+
+    jbyteArray decryptedMsgRet = 0;
+
+    jclass encryptedMsgJClass = 0;
+    jstring encryptedMsgJstring = 0; // <= obtained from encryptedMsgFieldId
+    // field IDs
+    jfieldID encryptedMsgFieldId;
+    jfieldID typeMsgFieldId;
+    // ptrs
+    OlmSession *sessionPtr = getSessionInstanceId(env, thiz);
+    const char *encryptedMsgPtr = NULL; // <= obtained from encryptedMsgJstring
+    uint8_t *plainTextMsgPtr = NULL;
+    char *tempEncryptedPtr = NULL;
+
+    LOGD("## decryptMessageJni(): IN - OlmSession");
+
+    if (!sessionPtr)
+    {
+        LOGE("## decryptMessageJni(): failure - invalid Session ptr=NULL");
+        errorMessage = "invalid Session ptr=NULL";
+    }
+    else if (!aEncryptedMsg)
+    {
+        LOGE("## decryptMessageJni(): failure - invalid encrypted message");
+        errorMessage = "invalid encrypted message";
+    }
+    else if (!(encryptedMsgJClass = env->GetObjectClass(aEncryptedMsg)))
+    {
+        LOGE("## decryptMessageJni(): failure - unable to get encrypted message class");
+        errorMessage = "unable to get encrypted message class";
+    }
+    else if (!(encryptedMsgFieldId = env->GetFieldID(encryptedMsgJClass,"mCipherText","Ljava/lang/String;")))
+    {
+        LOGE("## decryptMessageJni(): failure - unable to get message field");
+        errorMessage = "unable to get message field";
+    }
+    else if (!(typeMsgFieldId = env->GetFieldID(encryptedMsgJClass,"mType","J")))
+    {
+        LOGE("## decryptMessageJni(): failure - unable to get message type field");
+        errorMessage = "unable to get message type field";
+    }
+    else if (!(encryptedMsgJstring = (jstring)env->GetObjectField(aEncryptedMsg, encryptedMsgFieldId)))
+    {
+        LOGE("## decryptMessageJni(): failure - JNI encrypted object ");
+        errorMessage = "JNI encrypted object";
+    }
+    else if (!(encryptedMsgPtr = env->GetStringUTFChars(encryptedMsgJstring, 0)))
+    {
+        LOGE("## decryptMessageJni(): failure - encrypted message JNI allocation OOM");
+        errorMessage = "encrypted message JNI allocation OOM";
+    }
+    else
+    {
+        // get message type
+        size_t encryptedMsgType = (size_t)env->GetLongField(aEncryptedMsg, typeMsgFieldId);
+        // get encrypted message length
+        size_t encryptedMsgLength = (size_t)env->GetStringUTFLength(encryptedMsgJstring);
+
+        // create a dedicated temp buffer to be used in next Olm API calls
+        tempEncryptedPtr = static_cast<char*>(malloc(encryptedMsgLength*sizeof(uint8_t)));
+        memcpy(tempEncryptedPtr, encryptedMsgPtr, encryptedMsgLength);
+        LOGD("## decryptMessageJni(): MsgType=%lu encryptedMsgLength=%lu encryptedMsg=%.*s",static_cast<long unsigned int>(encryptedMsgType),static_cast<long unsigned int>(encryptedMsgLength), static_cast<int>(encryptedMsgLength), encryptedMsgPtr);
+
+        // get max plaintext length
+        size_t maxPlainTextLength = olm_decrypt_max_plaintext_length(sessionPtr,
+                                                                     static_cast<size_t>(encryptedMsgType),
+                                                                     static_cast<void*>(tempEncryptedPtr),
+                                                                     encryptedMsgLength);
+        // Note: tempEncryptedPtr is destroyed by olm_decrypt_max_plaintext_length()
+
+        if (maxPlainTextLength == olm_error())
+        {
+            errorMessage = (const char *)olm_session_last_error(sessionPtr);
+            LOGE("## decryptMessageJni(): failure - olm_decrypt_max_plaintext_length Msg=%s", errorMessage);
+        }
+        else
+        {
+            LOGD("## decryptMessageJni(): maxPlaintextLength=%lu",static_cast<long unsigned int>(maxPlainTextLength));
+
+            // allocate output decrypted message
+            plainTextMsgPtr = static_cast<uint8_t*>(malloc(maxPlainTextLength*sizeof(uint8_t)));
+
+            // decrypt, but before reload encrypted buffer (previous one was destroyed)
+            memcpy(tempEncryptedPtr, encryptedMsgPtr, encryptedMsgLength);
+            size_t plaintextLength = olm_decrypt(sessionPtr,
+                                                 encryptedMsgType,
+                                                 (void*)tempEncryptedPtr,
+                                                 encryptedMsgLength,
+                                                 plainTextMsgPtr,
+                                                 maxPlainTextLength);
+            if (plaintextLength == olm_error())
+            {
+                errorMessage = (const char *)olm_session_last_error(sessionPtr);
+                LOGE("## decryptMessageJni(): failure - olm_decrypt Msg=%s", errorMessage);
+            }
+            else
+            {
+                decryptedMsgRet = env->NewByteArray(plaintextLength);
+                env->SetByteArrayRegion(decryptedMsgRet, 0 , plaintextLength, (jbyte*)plainTextMsgPtr);
+
+                LOGD(" ## decryptMessageJni(): UTF-8 Conversion - decrypted returnedLg=%lu OK",static_cast<long unsigned int>(plaintextLength));
+            }
+        }
+    }
+
+    // free alloc
+    if (encryptedMsgPtr)
+    {
+        env->ReleaseStringUTFChars(encryptedMsgJstring, encryptedMsgPtr);
+    }
+
+    if (tempEncryptedPtr)
+    {
+        free(tempEncryptedPtr);
+    }
+
+    if (plainTextMsgPtr)
+    {
+        free(plainTextMsgPtr);
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return decryptedMsgRet;
+}
+
+/**
+ * Get the session identifier for this session.
+ * An exception is thrown if the operation fails.
+ * @return the session identifier
+ */
+JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(getSessionIdentifierJni)(JNIEnv *env, jobject thiz)
+{
+     const char* errorMessage = NULL;
+     jbyteArray returnValue = 0;
+
+     LOGD("## getSessionIdentifierJni(): IN ");
+
+     OlmSession *sessionPtr = getSessionInstanceId(env, thiz);
+
+     if (!sessionPtr)
+     {
+         LOGE("## getSessionIdentifierJni(): failure - invalid Session ptr=NULL");
+         errorMessage = "invalid Session ptr=NULL";
+     }
+     else
+     {
+         // get the size to alloc to contain the id
+         size_t lengthSessionId = olm_session_id_length(sessionPtr);
+         LOGD("## getSessionIdentifierJni(): lengthSessionId=%lu",static_cast<long unsigned int>(lengthSessionId));
+
+         void *sessionIdPtr = malloc(lengthSessionId*sizeof(uint8_t));
+
+         if (!sessionIdPtr)
+         {
+            LOGE("## getSessionIdentifierJni(): failure - identifier allocation OOM");
+            errorMessage = "identifier allocation OOM";
+         }
+         else
+         {
+             size_t result = olm_session_id(sessionPtr, sessionIdPtr, lengthSessionId);
+
+             if (result == olm_error())
+             {
+                 errorMessage = (const char *)olm_session_last_error(sessionPtr);
+                 LOGE("## getSessionIdentifierJni(): failure - get session identifier failure Msg=%s", errorMessage);
+             }
+             else
+             {
+                 LOGD("## getSessionIdentifierJni(): success - result=%lu sessionId=%.*s",static_cast<long unsigned int>(result), static_cast<int>(result), (char*)sessionIdPtr);
+
+                 returnValue = env->NewByteArray(result);
+                 env->SetByteArrayRegion(returnValue, 0 , result, (jbyte*)sessionIdPtr);
+             }
+
+             free(sessionIdPtr);
+         }
+     }
+
+     if (errorMessage)
+     {
+         env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+     }
+
+     return returnValue;
+}
+
+/**
+ * Serialize and encrypt session instance.<br>
+ * An exception is thrown if the operation fails.
+ * @param aKeyBuffer key used to encrypt the serialized account data
+ * @return the serialised account as bytes buffer.
+ **/
+JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(serializeJni)(JNIEnv *env, jobject thiz, jbyteArray aKeyBuffer)
+{
+    const char* errorMessage = NULL;
+    jbyteArray returnValue = 0;
+
+    jbyte* keyPtr = NULL;
+    OlmSession* sessionPtr = getSessionInstanceId(env, thiz);
+
+    LOGD("## serializeJni(): IN");
+
+    if (!sessionPtr)
+    {
+        LOGE(" ## serializeJni(): failure - invalid session ptr");
+        errorMessage = "invalid session ptr";
+    }
+    else if (!aKeyBuffer)
+    {
+        LOGE(" ## serializeJni(): failure - invalid key");
+        errorMessage = "invalid key";
+    }
+    else if (!(keyPtr = env->GetByteArrayElements(aKeyBuffer, 0)))
+    {
+        LOGE(" ## serializeJni(): failure - keyPtr JNI allocation OOM");
+        errorMessage = "ikeyPtr JNI allocation OOM";
+    }
+    else
+    {
+        size_t pickledLength = olm_pickle_session_length(sessionPtr);
+        size_t keyLength = (size_t)env->GetArrayLength(aKeyBuffer);
+        LOGD(" ## serializeJni(): pickledLength=%lu keyLength=%lu",static_cast<long unsigned int>(pickledLength), static_cast<long unsigned int>(keyLength));
+
+        void *pickledPtr = malloc(pickledLength*sizeof(uint8_t));
+
+        if (!pickledPtr)
+        {
+            LOGE(" ## serializeJni(): failure - pickledPtr buffer OOM");
+            errorMessage = "pickledPtr buffer OOM";
+        }
+        else
+        {
+            size_t result = olm_pickle_session(sessionPtr,
+                                              (void const *)keyPtr,
+                                              keyLength,
+                                              (void*)pickledPtr,
+                                              pickledLength);
+            if (result == olm_error())
+            {
+                errorMessage = olm_session_last_error(sessionPtr);
+                LOGE(" ## serializeJni(): failure - olm_pickle_session() Msg=%s", errorMessage);
+            }
+            else
+            {
+                LOGD(" ## serializeJni(): success - result=%lu pickled=%.*s", static_cast<long unsigned int>(result), static_cast<int>(pickledLength), static_cast<char*>(pickledPtr));
+
+                returnValue = env->NewByteArray(pickledLength);
+                env->SetByteArrayRegion(returnValue, 0 , pickledLength, (jbyte*)pickledPtr);
+            }
+
+            free(pickledPtr);
+        }
+    }
+
+    // free alloc
+    if (keyPtr)
+    {
+        env->ReleaseByteArrayElements(aKeyBuffer, keyPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return returnValue;
+}
+
+/**
+ * Allocate a new session and initialize it with the serialisation data.<br>
+ * An exception is thrown if the operation fails.
+ * @param aSerializedData the session serialisation buffer
+ * @param aKey the key used to encrypt the serialized account data
+ * @return the deserialized session
+ **/
+JNIEXPORT jlong OLM_SESSION_FUNC_DEF(deserializeJni)(JNIEnv *env, jobject thiz, jbyteArray aSerializedDataBuffer, jbyteArray aKeyBuffer)
+{
+    const char* errorMessage = NULL;
+    OlmSession* sessionPtr = initializeSessionMemory();
+    jbyte* keyPtr = NULL;
+    jbyte* pickledPtr = NULL;
+
+    LOGD("## deserializeJni(): IN");
+
+    if (!sessionPtr)
+    {
+        LOGE(" ## deserializeJni(): failure - session failure OOM");
+        errorMessage = "session failure OOM";
+    }
+    else if (!aKeyBuffer)
+    {
+        LOGE(" ## deserializeJni(): failure - invalid key");
+        errorMessage = "invalid key";
+    }
+    else if (!aSerializedDataBuffer)
+    {
+        LOGE(" ## deserializeJni(): failure - serialized data");
+        errorMessage = "serialized data";
+    }
+    else if (!(keyPtr = env->GetByteArrayElements(aKeyBuffer, 0)))
+    {
+        LOGE(" ## deserializeJni(): failure - keyPtr JNI allocation OOM");
+        errorMessage = "keyPtr JNI allocation OOM";
+    }
+    else if (!(pickledPtr = env->GetByteArrayElements(aSerializedDataBuffer, 0)))
+    {
+        LOGE(" ## deserializeJni(): failure - pickledPtr JNI allocation OOM");
+        errorMessage = "pickledPtr JNI allocation OOM";
+    }
+    else
+    {
+        size_t pickledLength = (size_t)env->GetArrayLength(aSerializedDataBuffer);
+        size_t keyLength = (size_t)env->GetArrayLength(aKeyBuffer);
+        LOGD(" ## deserializeJni(): pickledLength=%lu keyLength=%lu",static_cast<long unsigned int>(pickledLength), static_cast<long unsigned int>(keyLength));
+        LOGD(" ## deserializeJni(): pickled=%.*s",static_cast<int>(pickledLength), (char const *)pickledPtr);
+
+        size_t result = olm_unpickle_session(sessionPtr,
+                                             (void const *)keyPtr,
+                                             keyLength,
+                                             (void*)pickledPtr,
+                                             pickledLength);
+        if (result == olm_error())
+        {
+            errorMessage = olm_session_last_error(sessionPtr);
+            LOGE(" ## deserializeJni(): failure - olm_unpickle_account() Msg=%s", errorMessage);
+        }
+        else
+        {
+            LOGD(" ## initJni(): success - result=%lu ", static_cast<long unsigned int>(result));
+        }
+    }
+
+    // free alloc
+    if (keyPtr)
+    {
+        env->ReleaseByteArrayElements(aKeyBuffer, keyPtr, JNI_ABORT);
+    }
+
+    if (pickledPtr)
+    {
+        env->ReleaseByteArrayElements(aSerializedDataBuffer, pickledPtr, JNI_ABORT);
+    }
+
+    if (errorMessage)
+    {
+        if (sessionPtr)
+        {
+            olm_clear_session(sessionPtr);
+            free(sessionPtr);
+        }
+        env->ThrowNew(env->FindClass("java/lang/Exception"), errorMessage);
+    }
+
+    return (jlong)(intptr_t)sessionPtr;
+}
\ No newline at end of file
diff --git a/android/olm-sdk/src/main/jni/olm_session.h b/android/olm-sdk/src/main/jni/olm_session.h
new file mode 100644
index 0000000..b8cdd2f
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_session.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _OMLSESSION_H
+#define _OMLSESSION_H
+
+#include "olm_jni.h"
+#include "olm/olm.h"
+
+#define OLM_SESSION_FUNC_DEF(func_name) FUNC_DEF(OlmSession,func_name)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// session creation/destruction
+JNIEXPORT void OLM_SESSION_FUNC_DEF(releaseSessionJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jlong OLM_SESSION_FUNC_DEF(createNewSessionJni)(JNIEnv *env, jobject thiz);
+
+// outbound session
+JNIEXPORT void OLM_SESSION_FUNC_DEF(initOutboundSessionJni)(JNIEnv *env, jobject thiz, jlong aOlmAccountId, jbyteArray aTheirIdentityKey, jbyteArray aTheirOneTimeKey);
+
+// inbound sessions: establishment based on PRE KEY message
+JNIEXPORT void OLM_SESSION_FUNC_DEF(initInboundSessionJni)(JNIEnv *env, jobject thiz, jlong aOlmAccountId, jbyteArray aOneTimeKeyMsg);
+JNIEXPORT void OLM_SESSION_FUNC_DEF(initInboundSessionFromIdKeyJni)(JNIEnv *env, jobject thiz, jlong aOlmAccountId, jbyteArray aTheirIdentityKey, jbyteArray aOneTimeKeyMsg);
+
+// match inbound sessions: based on PRE KEY message
+JNIEXPORT jboolean OLM_SESSION_FUNC_DEF(matchesInboundSessionJni)(JNIEnv *env, jobject thiz, jbyteArray aOneTimeKeyMsg);
+JNIEXPORT jboolean OLM_SESSION_FUNC_DEF(matchesInboundSessionFromIdKeyJni)(JNIEnv *env, jobject thiz, jbyteArray aTheirIdentityKey, jbyteArray aOneTimeKeyMsg);
+
+// encrypt/decrypt
+JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(encryptMessageJni)(JNIEnv *env, jobject thiz, jbyteArray aClearMsg, jobject aEncryptedMsg);
+JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(decryptMessageJni)(JNIEnv *env, jobject thiz, jobject aEncryptedMsg);
+
+JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(getSessionIdentifierJni)(JNIEnv *env, jobject thiz);
+
+// serialization
+JNIEXPORT jbyteArray OLM_SESSION_FUNC_DEF(serializeJni)(JNIEnv *env, jobject thiz, jbyteArray aKey);
+JNIEXPORT jlong OLM_SESSION_FUNC_DEF(deserializeJni)(JNIEnv *env, jobject thiz, jbyteArray aSerializedData, jbyteArray aKey);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/android/olm-sdk/src/main/jni/olm_utility.cpp b/android/olm-sdk/src/main/jni/olm_utility.cpp
new file mode 100644
index 0000000..f6fe719
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_utility.cpp
@@ -0,0 +1,228 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "olm_utility.h"
+
+using namespace AndroidOlmSdk;
+
+OlmUtility* initializeUtilityMemory()
+{
+    size_t utilitySize = olm_utility_size();
+    OlmUtility* utilityPtr = (OlmUtility*)malloc(utilitySize);
+
+    if (utilityPtr)
+    {
+        utilityPtr = olm_utility(utilityPtr);
+        LOGD("## initializeUtilityMemory(): success - OLM utility size=%lu",static_cast<long unsigned int>(utilitySize));
+    }
+    else
+    {
+        LOGE("## initializeUtilityMemory(): failure - OOM");
+    }
+
+    return utilityPtr;
+}
+
+JNIEXPORT jlong OLM_UTILITY_FUNC_DEF(createUtilityJni)(JNIEnv *env, jobject thiz)
+{
+    OlmUtility* utilityPtr = initializeUtilityMemory();
+
+    LOGD("## createUtilityJni(): IN");
+
+    // init account memory allocation
+    if (!utilityPtr)
+    {
+        LOGE(" ## createUtilityJni(): failure - init OOM");
+        env->ThrowNew(env->FindClass("java/lang/Exception"), "init OOM");
+    }
+    else
+    {
+       LOGD(" ## createUtilityJni(): success");
+    }
+
+    return (jlong)(intptr_t)utilityPtr;
+}
+
+
+JNIEXPORT void OLM_UTILITY_FUNC_DEF(releaseUtilityJni)(JNIEnv *env, jobject thiz)
+{
+    OlmUtility* utilityPtr = getUtilityInstanceId(env, thiz);
+
+    LOGD("## releaseUtilityJni(): IN");
+
+    if (!utilityPtr)
+    {
+        LOGE("## releaseUtilityJni(): failure - utility ptr=NULL");
+    }
+    else
+    {
+        olm_clear_utility(utilityPtr);
+        free(utilityPtr);
+    }
+}
+
+
+/**
+ * Verify an ed25519 signature.
+ * @param aSignature the base64-encoded message signature to be checked.
+ * @param aKey the ed25519 key (fingerprint key)
+ * @param aMessage the message which was signed
+ * @return 0 if validation succeed, an error message string if operation failed
+ */
+JNIEXPORT jstring OLM_UTILITY_FUNC_DEF(verifyEd25519SignatureJni)(JNIEnv *env, jobject thiz, jbyteArray aSignatureBuffer, jbyteArray aKeyBuffer, jbyteArray aMessageBuffer)
+{
+    jstring errorMessageRetValue = 0;
+    OlmUtility* utilityPtr = getUtilityInstanceId(env, thiz);
+    jbyte* signaturePtr = NULL;
+    jbyte* keyPtr = NULL;
+    jbyte* messagePtr = NULL;
+
+    LOGD("## verifyEd25519SignatureJni(): IN");
+
+    if (!utilityPtr)
+    {
+        LOGE(" ## verifyEd25519SignatureJni(): failure - invalid utility ptr=NULL");
+    }
+    else if (!aSignatureBuffer || !aKeyBuffer || !aMessageBuffer)
+    {
+        LOGE(" ## verifyEd25519SignatureJni(): failure - invalid input parameters ");
+    }
+    else if (!(signaturePtr = env->GetByteArrayElements(aSignatureBuffer, 0)))
+    {
+        LOGE(" ## verifyEd25519SignatureJni(): failure - signature JNI allocation OOM");
+    }
+    else if (!(keyPtr = env->GetByteArrayElements(aKeyBuffer, 0)))
+    {
+        LOGE(" ## verifyEd25519SignatureJni(): failure - key JNI allocation OOM");
+    }
+    else if (!(messagePtr = env->GetByteArrayElements(aMessageBuffer, 0)))
+    {
+        LOGE(" ## verifyEd25519SignatureJni(): failure - message JNI allocation OOM");
+    }
+    else
+    {
+        size_t signatureLength = (size_t)env->GetArrayLength(aSignatureBuffer);
+        size_t keyLength = (size_t)env->GetArrayLength(aKeyBuffer);
+        size_t messageLength = (size_t)env->GetArrayLength(aMessageBuffer);
+        LOGD(" ## verifyEd25519SignatureJni(): signatureLength=%lu keyLength=%lu messageLength=%lu",static_cast<long unsigned int>(signatureLength),static_cast<long unsigned int>(keyLength),static_cast<long unsigned int>(messageLength));
+        LOGD(" ## verifyEd25519SignatureJni(): key=%.*s", static_cast<int>(keyLength), keyPtr);
+
+        size_t result = olm_ed25519_verify(utilityPtr,
+                                           (void const *)keyPtr,
+                                           keyLength,
+                                           (void const *)messagePtr,
+                                           messageLength,
+                                           (void*)signaturePtr,
+                                           signatureLength);
+        if (result == olm_error()) {
+            const char *errorMsgPtr = olm_utility_last_error(utilityPtr);
+            errorMessageRetValue = env->NewStringUTF(errorMsgPtr);
+            LOGE("## verifyEd25519SignatureJni(): failure - olm_ed25519_verify Msg=%s",errorMsgPtr);
+        }
+        else
+        {
+            LOGD("## verifyEd25519SignatureJni(): success - result=%lu", static_cast<long unsigned int>(result));
+        }
+    }
+
+    // free alloc
+    if (signaturePtr)
+    {
+        env->ReleaseByteArrayElements(aSignatureBuffer, signaturePtr, JNI_ABORT);
+    }
+
+    if (keyPtr)
+    {
+        env->ReleaseByteArrayElements(aKeyBuffer, keyPtr, JNI_ABORT);
+    }
+
+    if (messagePtr)
+    {
+        env->ReleaseByteArrayElements(aMessageBuffer, messagePtr, JNI_ABORT);
+    }
+
+    return errorMessageRetValue;
+}
+
+/**
+ * Compute the digest (SHA 256) for the message passed in parameter.<br>
+ * The digest value is the function return value.
+ * An exception is thrown if the operation fails.
+ * @param aMessage the message
+ * @return digest of the message.
+ **/
+JNIEXPORT jbyteArray OLM_UTILITY_FUNC_DEF(sha256Jni)(JNIEnv *env, jobject thiz, jbyteArray aMessageToHashBuffer)
+{
+    jbyteArray sha256Ret = 0;
+
+    OlmUtility* utilityPtr = getUtilityInstanceId(env, thiz);
+    jbyte* messagePtr = NULL;
+
+    LOGD("## sha256Jni(): IN");
+
+    if (!utilityPtr)
+    {
+        LOGE(" ## sha256Jni(): failure - invalid utility ptr=NULL");
+    }
+    else if(!aMessageToHashBuffer)
+    {
+        LOGE(" ## sha256Jni(): failure - invalid message parameters ");
+    }
+    else if(!(messagePtr = env->GetByteArrayElements(aMessageToHashBuffer, 0)))
+    {
+        LOGE(" ## sha256Jni(): failure - message JNI allocation OOM");
+    }
+    else
+    {
+        // get lengths
+        size_t messageLength = (size_t)env->GetArrayLength(aMessageToHashBuffer);
+        size_t hashLength = olm_sha256_length(utilityPtr);
+        void* hashValuePtr = malloc((hashLength)*sizeof(uint8_t));
+
+        if (!hashValuePtr)
+        {
+            LOGE("## sha256Jni(): failure - hash value allocation OOM");
+        }
+        else
+        {
+            size_t result = olm_sha256(utilityPtr,
+                                       (void const *)messagePtr,
+                                       messageLength,
+                                       (void *)hashValuePtr,
+                                       hashLength);
+            if (result == olm_error())
+            {
+                LOGE("## sha256Jni(): failure - hash creation Msg=%s",(const char *)olm_utility_last_error(utilityPtr));
+            }
+            else
+            {
+                LOGD("## sha256Jni(): success - result=%lu hashValue=%.*s",static_cast<long unsigned int>(result), static_cast<int>(result), (char*)hashValuePtr);
+                sha256Ret = env->NewByteArray(result);
+                env->SetByteArrayRegion(sha256Ret, 0 , result, (jbyte*)hashValuePtr);
+            }
+
+            free(hashValuePtr);
+        }
+    }
+
+    if (messagePtr)
+    {
+        env->ReleaseByteArrayElements(aMessageToHashBuffer, messagePtr, JNI_ABORT);
+    }
+
+    return sha256Ret;
+}
\ No newline at end of file
diff --git a/android/olm-sdk/src/main/jni/olm_utility.h b/android/olm-sdk/src/main/jni/olm_utility.h
new file mode 100644
index 0000000..de4b290
--- /dev/null
+++ b/android/olm-sdk/src/main/jni/olm_utility.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2016 OpenMarket Ltd
+ * Copyright 2016 Vector Creations Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _OMLUTILITY_H
+#define _OMLUTILITY_H
+
+#include "olm_jni.h"
+#include "olm/olm.h"
+
+#define OLM_UTILITY_FUNC_DEF(func_name) FUNC_DEF(OlmUtility,func_name)
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+JNIEXPORT jlong   OLM_UTILITY_FUNC_DEF(createUtilityJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT void    OLM_UTILITY_FUNC_DEF(releaseUtilityJni)(JNIEnv *env, jobject thiz);
+JNIEXPORT jstring OLM_UTILITY_FUNC_DEF(verifyEd25519SignatureJni)(JNIEnv *env, jobject thiz, jbyteArray aSignature, jbyteArray aKey, jbyteArray aMessage);
+JNIEXPORT jbyteArray OLM_UTILITY_FUNC_DEF(sha256Jni)(JNIEnv *env, jobject thiz, jbyteArray aMessageToHash);
+#ifdef __cplusplus
+}
+#endif
+
+
+
+#endif
diff --git a/android/olm-sdk/src/main/res/values/strings.xml b/android/olm-sdk/src/main/res/values/strings.xml
new file mode 100644
index 0000000..93bea1d
--- /dev/null
+++ b/android/olm-sdk/src/main/res/values/strings.xml
@@ -0,0 +1,3 @@
+<resources>
+    <string name="app_name">OlmSdk</string>
+</resources>