Abstract or Summary:
Inspired from the Diffie-Hellman key distribution system and the ElGamal's digital signature scheme, we propose a password authentication scheme in this paper. By the implementation of smart cards, a user can originate a login request without revealing his possessed password in an insecure channel. Without any verification table, our scheme can verify users' login requests easily. A timestamp is also embedded in users' login requests against the potential attacks on replaying previously intercepted login requests.