libotr is a library and toolkit which implements Off-the-Record (OTR)
Messaging.

OTR allows you to have private conversations over IM by providing:
- Encryption
- No one else can read your instant messages.
- Authentication
- You are assured the correspondent is who you think it is.
- Deniability
- The messages you send do _not_ have digital signatures that are
checkable by a third party. Anyone can forge messages after a
conversation to make them look like they came from you. However,
_during_ a conversation, your correspondent is assured the messages
he sees are authentic and unmodified.
- Perfect forward secrecy
- If you lose control of your private keys, no previous conversation
is compromised.