@inference I saw where you previously critiqued Matrix and said Signal is good enough. I agree that security could have been implemented better with Matrix. I remember using Riot years before Element, while the service implemented more and more advanced encryption, it was implemented worse than previous attempts.
I agree about Signal. It's a solid service and open enough.
What are your thoughts on Briar? I've found it quite usable and it seems secure enough. If you haven't tried it I hope you have two working phones to use.
@inference That's a fair assessment.
I will point out that Briar omits certain features but it does this to allow for deniability. Outside of a war zone, this can indeed cause problems. It is surprisingly feature rich for what it is and not difficult to use.
Signal is the best for now. It has the best encryption I've seen implemented and ease of use. There's not much reason to not use the service, even from a FLOSS viewpoint. (IE hypocritical to criticize a non Libre service that almost entirely relies on non free infrastructure.)
You do hide metadata with those services, but it's not worth the security risks of talking to someone who has compromised an account and make you believe you're talking to your real contact. There are no per-session keys like what Signal, XMPP, Matrix, and even WhatsApp, have; you are blindly trusting that you're talking to the real contact and their account has not been compromised.
Signal does the best job at hiding metadata without an onion service, and its security/encryption is what almost every other messenger today is based on, including XMPP, Matrix, and WhatsApp; you can't get any better.