Can you guys suggest some reliable and secure selfhosted IM service? I’m kinda in a very bad spot right now, so any centralized messaging wouldn’t really work. And yeah, state sponsored mass surveillance is a question of concern. Sorry for odd phrasing, just really at a loss.
I heard of matrix, XMPP (heard good things about snikket.org), SimpleX and even some IRC wizardry over TOR. And I actually tried matrix (synapse server), but found it not reliable enough - sometimes skips a notification, periodic troubles with logging in, weird lack of voice calls on mobile client, and some other irritating, tiny hiccups. I’m open to any suggestion, really, even open to trying matrix once again. Just, please, describe why you think one option is better than the other.
And just FYI, use case is simply texting with friends and family, while avoiding state monitoring. Nothing nefarious
Huh - you’re right. I went back to Signal’s X3DH spec because I was sure I was right, but it seems I misremembered how the “prekey bundles” work: Users publish these to the server, allowing (in my original assumption) for the server to just swap them out for a server/attacker-controlled key bundle for each Alice and Bob.
However, when Alice wants to send Bob an initial message and she gets a forged prekey bundle, Bob will simply not be able to derive the same key and communication will fail, because Bob knows what his SPK private key is, while the server only knows the public key.