It will be open source, end to end encrypted using Signal’s double ratchet encryption protocol, and he plans to make it easy for fediverse platforms to integrate it. The beta will release later this month.
He’s also the creator of https://fedidb.org btw
You’re right, Signal is not P2P. The way Signals messaging pipeline works is like this - note I’m oversimplifying it for accessibility.
Sending a message to
Bob
Send
.Bob
.Bob
- this means Signal’s server can see its a unique user, but not what their name is.See their blog post about Private Contact Discovery, they’ve spent a long time figuring out how to engineer a method to know as little as possible about you.