https://github.com/amir734jj/symmetric-crypto-chat-room

I started working on this many years ago and incrementally improved this over-time. The idea is if two people choose a (channel + encryption key) then they should be able to communicate with each other (text, file, audio, video) fully encrypted all in your browser. The "server" just relays the data. It doesn't know what is being send/received.

If you join the channel with wrong encryption key, you will just receive garbage data.