We had a few readers suggest Signal as their favorite secure messaging system (in our item last week about Telegram). Security boasts that they have state-of-the-art end-to-end encryption (powered by the open source Signal Protocol) which will keep your conversations secure. They say they can’t read your messages or listen to your calls, and no one else can either. They have no ads and it’s an independent nonprofit. www.signal.org. How would you compare Telegram vs. Signal? What do you use?
This gives a great comparison of many messenger apps:
https://www.messenger-matrix.de/messenger-matrix-en.html
I use Signal, Threema and Wire. I would say Threema is the most secure of these but has not yet all the features of the others. Wire is great if you would like to use on up to five devices at the same time (computer, tablet and smartphones).
Signal is very secure. They are open source, which means that their source code can be audited by external people (and is, yearly). Messages are encrypted on your phone using a very high grade algorithm, and only decrypted on the reading device. So they can’t read your messages. They are (so far) not owned by any of the big social media companies. Our org (world-outreach.com) prefers this app.