SILC was designed by Pekka Riikonen between 1996 and 1999 and first released in public in summer 2000. A client and a server were written. Protocol specifications were proposed, but ultimately request for publication was denied in June 2004 by IESG and no RFC has been published to date. 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 Pidgin instant messaging client. Other GUI clients are Silky and Colloquy. The Silky client was put on hold and abandoned on the 18th of July 2007, due to inactivity for several years. The latest news on the Silky website was that the client was to be completely rewritten. As of 2008, three SILC protocol implementations have been written. Most SILC clients use libsilc, part of the SILC Toolkit. The SILC Toolkit is dual-licensed and distributed under both the GNU General Public License (GPL) and the revised BSD license. Security As described in the SILC FAQ, chats are secured through the generation of symmetric encryption keys. These keys have to be generated somewhere, and this occurs on the server. This means that chats might be compromised, if the server itself is compromised. This is just a version of the man-in-the-middle attack. The solution offered is that chat members generate their own public-private keypair for asymmetric encryption. The private key is shared only by the chat members, and this is done out of band. The public key is used to encrypt messages into the channel. This approach is still open to compromise, if one of the members of the chat should have their private key compromised, or if they should share the key with another, without agreement of the group. Networks SILC uses a similar pattern to IRC, in that there is no global "SILC network" but many small independent networks consisting of one or several servers each, although it is claimed that SILC can scale better with many servers in a single network. The "original" network is called SILCNet, at the round-robin. However, as of May 2014, it has only one active (though unstable) server out of four. Most SILC networks have shut down due to declining popularity of SILC. See also Synchronous conferencing Comparison of instant messaging protocols Multiprotocol instant messaging application Public-key cryptography References External links The SILC Project Internet protocols Instant messaging