See http://silcnet.org/ for detailed information.
SILC provides common chat and conferencing services like private messages, instant messages, channels and groups, and video and audio conferencing. The main difference to other protocols is that SILC has been designed with security as its main feature.
All packets and messages sent in SILC network are always encrypted. Private messages are encrypted end-to-end, channel message are encrypted with channel-wide secret key and secure file...