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 https:/

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 https://en.wikipedia.org/wiki/SILC_%28protocol%29 (see "security" section, and technical details in http://www.silcnet.org/support/faq/crypto/ http://www.silcnet.org/support/faq/crypto/ )