@Jenetrix I'll play devils advocate here and point two things. Encryption for public chatrooms doesn't provide any benefits, it's a public room already. Secondly, e2ee solutions if you don't verify identities/keys out of band provide no security either, you might be being mitm-ed and you won't know it unless you verify each other.

So it's important to note what your usecase is.

@erethon @Jenetrix I wouldn't necessarily characterize all multiuser chat platforms as "public;" there are plenty of use cases where you have a community chat, but you wouldn't want an uninvited third party intercepting the discussion — marginalized people living under oppressive regimes but wanting or needing to find community springs to mind.

(That said, keeping multiuser plaintext comms off the platform operator's system gets into complicated key management problems, as you touch upon.)

@jima I agree, not all multi-user rooms are meant to be public, my comment was specifically about public/open-for-everyone-to-join rooms where encryption doesn't provide any benefits.

Besides the key management problems, another common failure I've seen in various circles is people feeling they're in a safe environment because the chat is e2ee, while also having threat actors (i.e. cops) in the room that can read all messages. As the number of people in a room increases, things get harder.