I am looking for a way to backup my private key for the Signal messenger application. Nothing has worked so far, and I am curious whether anyone can confirm or deny that Titanium backup will save and restore the private key of a Signal install.
Signal 4.17.0 introduced encrypted backups. This is the preferred migration path. Also the Titanium Backup route does not work in current releases.
I just tried this and it worked flawlessly.
After restoring Signal on your new Phone you should re-activated your connection by unregistering and re-registering to the Signal servers. As of now you can do this in the Signal Settings > Advanced tab by toggleing Signal messages to de-activate then re-activate . In this Process you will have to re-verify your phone number and you'll have to reconnect your Signal-Desktop clients afterwards.
You won't loose your Private key or your Signal-Desktop messages though.