Pidgin-paranoia is a plugin for Pidgin (formerly known as Gaim) that provides information-theoretically secure encrypted conversations using one-time pads. Because the plugin uses a one-time pad where the secret key has the same length as the message and the key is only used once, the encryption is information-theoretically secure. This means that from the encrypted messages the contents of the messages are not revealed. In short: If you use truly random numbers to generate the key files, and if you keep them perfectly secret, one-time pads can not be broken.
The Off-the-Record (OTR) Messaging proxy is a multi- platform proxy that allows you to have private conversations using the AIM client of your choice. It provides encryption, which prevents someone who intercepts your instant messages from reading them, authentication, which ensures that the correspondent is who you think it is, and perfect forward secrecy, which ensures that no previous conversation is compromised if you lose control of your private keys.
Off-the-Record (OTR) Messaging is a gaim plugin which allows you to have private conversations over the instant messaging system of your choice. It provides encryption, which prevents someone who intercepts your instant messages from reading them; authentication, which ensures that the correspondent is who you think it is; and perfect forward secrecy, which ensures that no previous conversation is compromised if you lose control of your private keys.
KDX is a powerful cross-platform BBS-style encrypted Internet communications system that provides messaging, news, file and folder transfer, voice chat (Internet Telephone), text chat, remote access, trackers, and more. It uses strong encryption to protect communications for security and privacy. It is useful for groups that need to collaborate on a project via the Internet. It is also very useful for remote administration of a computer. It uses a client/server architecture.
WASTE is a mesh-based workgroup tool that allows for encrypted, private communication between distant parties on the Internet, independent of local network organization. It is RSA secured, and has been heralded as the most secure P2P connection protocol currently in development. WASTE functions as a both a server and a client under *nix, Mac OS X, and Windows, as well as a server only mode under *nix and Windows.
CAKE (Key Addressed Crypto Encapsulation) is a bunch of Python and C++ for implementing the CAKE protocol. The CAKE protocol is a protocol in which all messages have source and destination addresses that are public keys. This is in the same way that IP packets have a source and destination address that is an IP address.