I use Signal and think it's pretty good while achieving its goals. The only other protocol I know that might be better for privacy is Tox, but it drains your ba

I use Signal and think it's pretty good while achieving its goals. The only other protocol I know that might be better for privacy is Tox, but it drains your bandwidth and any mobile device battery since it's decentralized. My litmus test is simple on if Signal is good enough. It's banned in most totalitarian nations. It has to be more secure than iMessage, and it's not like I use it for criminal activity so I'm happy with it. If that's peoples idea, you'd want to avoid all-things-convenient (the internet) and use intermediaries, deal in cash only, etc. For simple messaging without the government cataloguing your every word, Signal works great. The biggest threat to privacy is probably every device sold today having a microphone in it. Misuse for passive listening. Not the actions purposefully taken for communication like a text message.