14 Jul
1993
14 Jul
'93
5:52 p.m.
You can't even solve the problem with DH key exchange -- you are subject to "man in the middle" attacks. You must share SOME information via a secure channel in order to have both authentication and privacy on a channel. However, the information exchanged could be small and fairly one-time -- like the public key of a trusted entity that signs other public keys.
How do STU-III phones work then? Do they have some key in rom? Jim