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| -rw-r--r-- | docs/megolm.rst | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/docs/megolm.rst b/docs/megolm.rst index 4929349..03ee426 100644 --- a/docs/megolm.rst +++ b/docs/megolm.rst @@ -274,6 +274,17 @@ bytes preceding the signature. Limitations ----------- +Message Replays +--------------- + +A message can be decrypted successfully multiple times. This means that an +attacker can re-send a copy of an old message, and the recipient will treat it +as a new message. + +To mitigate this it is recommended that applications track the ratchet indices +they have received and that they reject messages with a ratchet index that +they have already decrypted. + Lack of Transcript Consistency ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |