[gizmo686]

I haven't looked at the code itself, but based on the usage section it seems like everyone in the room shares a secret key. I think the concept is that in order to get the secret key, you have to explicitly be given it by someone in the room.

[idupree]

By the way, there's an already-existing secure group chat software, SILC, that does something similar: https://en.wikipedia.org/wiki/SILC_%28protocol%29 (see "security" section, and technical details in http://www.silcnet.org/support/faq/crypto/ )