SILC (Secure Internet Live Conferencing) is a protocol which provides
secure conferencing services in the Internet over insecure channel.

SILC superficially resembles IRC, although they are very different
internally. SILC is much more than just about `encrypting the traffic'.
That is easy enough to do with IRC and SSL hybrids, but even then the
entire network cannot be secured, only part of it.

SILC provides security services, such as sending private messages entirely
secure; noone can see the message except you and the real receiver of the
message. SILC also provides same functionality for channels; noone except
those clients joined to the channel may see the messages destined to the
channel. Communication between client and server is also secured with
session keys and all commands, authentication data (such as passwords etc.)
and other traffic is entirely secured. The entire network, and all parts of
it, is secured.

SILC has secure key exchange protocol that is used to create the session keys
for each connection. SILC also provides strong authentication based on either
passwords or public key authentication. All authentication data is always
encrypted in the SILC network. Each connection has their own session keys,
all channels have channel specific keys, and all private messages can be
secured with private message specific keys.

Homepage:
http://www.silcnet.org/
