[SIP Beyond VoIP] New Python OTR library

Adrian Georgescu ag at ag-projects.com
Tue Jan 19 01:06:54 CET 2016

We made available a new Python library that implements versions 2 and 3 of the OTR protocol



This package implements the Off-The-Record Messaging protocol in pure python.

Off-The-Record Messaging (OTR) is a cryptographic protocol that provides
encryption for instant messaging conversations. OTR uses a combination of
AES symmetric-key algorithm with 128 bits key length, the Diffieb at SHellman
key exchange with 1536 bits group size, and the SHA-1/SHA-256 hash functions.

Features of the OTR protocol:

1. End-to-end encryption: No one else can read your messages.
2. Authentication: The correspondent's identity can be verified.
3. Deniability: The messages you send do not have digital signatures that can
   be checked by a third party. Anyone can forge messages after a conversation
   to make them look like they came from you, however during the conversation
   your correspondent is assured that the messages he sees coming from you are
   authentic and unmodified.
4. Perfect forward secrecy: If you lose control of your private keys, you are
   assured that no previous conversation is compromised.

The software can be downloaded from:



More information about the SIPBeyondVoIP mailing list