It's using MLS for encryption and key exchange, which is based in part in Signal's encryption. I believe they'll probably be using TOFU like all the other popu

It's using MLS for encryption and key exchange, which is based in part in Signal's encryption. I believe they'll probably be using TOFU like all the other popular encrypted messenger apps. Google's messenger (the encryption of which already uses MLS) has a verification feature where you can match key fingerprints by comparing numbers, but who knows how Apple will implement this.