Marking a safety code as trusted in signal is not different in any way to adding a self-signed TLS certificate to the trust store on your computer. You can perf

Marking a safety code as trusted in signal is not different in any way to adding a self-signed TLS certificate to the trust store on your computer. You can perform exactly the same out of band verification of the self-signed cert. Signal does not have a single feature that verifies the identity of your contacts, they don’t pretend to have such a feature, and frankly I’d say it’s dangerous to assert that they do. How you do that is 100% your own problem to solve. The only thing it does is provide you with a trust store to use to keep track of which contacts you have personally decided to trust.