In principle, you can solve this with gpg-signed messages (the message could be as simple as “yes, that’s me you’re talking to on the phone”). Anyone you give your public key to can verify anything you sign.
...the problem, of course, is persuading anyone else to use gpg. Good luck with that part. :-(
In principle, you can solve this with gpg-signed messages (the message could be as simple as “yes, that’s me you’re talking to on the phone”). Anyone you give your public key to can verify anything you sign.
...the problem, of course, is persuading anyone else to use gpg. Good luck with that part. :-(