On: Building end-to-end security for Messenger

[evbogue]

If the keys are stored on the server, how is that a private message?

[zer0zzz → evbogue]

Protonmail holds your key encrypted on the server. The key could be encrypted+decrypted by pin or by password.

[Dah00n → zer0zzz]

Does Proton (or Meta) see that Pin or password, or is it client-side only (as far as we know)?

[pferde → Dah00n]

Client side. The client downloads the encrypted key backup and decrypts it using user-entered pin/password.