The beginnings of public/private key authentication are in the code! We are using libsodium to do it, deriving signing and encryption keys off of a common seed much like bitcoin. Very primitive though. This stuff isn't appropriate for end-to-end encryption for sure. No forward secrecy or anything.
I'm not sure how far I want to go with that anyway. Encryption might disappear altogether from the base protocol. Perhaps smarter people than I can figure out how to do messaging layer security with this model?