There's pretty wide consensus that Signal is the most secure for now (minus the phone-number requirement, but whatever, not going there). Signal will likely con

There's pretty wide consensus that Signal is the most secure for now (minus the phone-number requirement, but whatever, not going there). Signal will likely continue to be the most secure platform for the short-to-medium future, and potentially longer. I disagree with Moxie on many things, but he really understands how to write secure code, and I trust him on security in a way that I don't trust many other people. Matrix is significantly less proven, leaks a bit more metadata (at the moment) and has had a few incidents that make people cautious about trusting it for real activism -- but it's a more future-proof investment if you're not currently an activist, and some of the stuff they're working on (most recently around P2P and mesh networks) may be really valuable in the future. Matrix is taking an explicit stance that concepts like federation and custom clients are not antithetical to privacy. It's yet to be seen whether they're right about that, but a lot of us want them to be right. We'd prefer to live in the world that they describe. Apps like WhatsApp and Telegram also exist, and I guess some people like them, but I don't see any reason to bring them to the table since Signal already exists and is already the gold standard for privacy. The only reason Matrix is on the table is because Matrix is fundamentally different from Signal in ways that are worth caring about. So in short: - If you really need to make sure nobody reads your messages, use Signal. Hands down, not even a contest. - If you're invested in the future of apps like this, and you have auxiliary concerns around federation, openness, and bridges that might outweigh your worries about potential vulnerabilities, then consider using Matrix. Nearly all of these apps are better than doing something like encrypting an email. Email encryption is a minefield of insecure clients and foot-guns.