All Your Instant Messages, Encrypted with OTR

Off-The-Record Messaging Protocol is a custom tailored encryption scheme for instant messaging based on public key encryption. In addition to the standard benefits of Public Key encryption, such as proving your identity, and encrypting your communication, OTR also offers plausible deniability. The best part of OTR Messaging Protocol is that its not just a white paper: It has support for most open IM clients. This is the standard for Instant Messaging encryption.