A Formal Security Analysis of the Signal Messaging Protocol
https://eprint.iacr.org/2016/1013 [eprint.iacr.org]
2016-11-08 22:09
Formerly Axolotl and now used by WhatsApp, Facebook Messenger, and Google Allo, besides the Signal (TextSecure) client.
The Signal protocol, and in particular its ratcheting construction, has a relatively complex history.