SILC (Secure Internet Live Conferencing protocol) is a data.

The SILC Key Exchange protocol (SKE) is used to establish session key and other security parameters for protecting the SILC Packet protocol using algorithms based on symmetric cryptography. The SKE is based on Diffie-Hellman key exchange algorithm (asymmetric cryptography) and the exchange is protected with digital signatures. The SILC Authentication protocol is performed after successful SKE protocol execution to authenticate a client and/or a server. The authentication may be based on passphrase or on digital signatures, and if successful gives access to SILC network. The SILC Packet protocol is a secure binary packet protocol and assures that the content of the packet (packet header and packet payload) is secured and authenticated. The packets are secured using algorithms based on symmetric cryptography and authenticated by using Message Authentication Code algorithm, HMAC.

SILC channels (groups) are protected by using symmetric channel keys. It is optionally possible to digitally sign all channels messages. It is also possible to protect messages with privately generated channel key, that has been previously agreed on between channel members. Private messages between users in the SILC network are protected with session keys. It is however possible to execute SKE protocol between two users and use the generated key to protect private messages. Private messages may be optionally digitally signed. When messages are secured with key material generated with SKE protocol or key material previously agreed on (for example, passphrases) SILC provides security even when SILC server may be compromised.

=History=

SILC was designed by Pekka Riikonen between 1996 and 1999 and first released in public in summer 2000. A client and a server was written. Protocol specifications have been iterated through the IETF. At present time, there are several clients, the most advanced being the official SILC client and an irssi plugin. SILC protocol is also integrated to the popular Gaim client. Other GUI clients are Silky and Colloquy. All of the above are supported on several platforms.

= External links =