Improvement on Peyravian-Zunic's password authentication schemes

Peyravian and Zunic (2000) presented two schemes for protecting password transmission and password change respectively. Like the traditional authentication scheme using passwords, the two new schemes are also vulnerable to attacks like guessing attacks, server spoofing, and server data eavesdropping. This paper will give demonstrations on what have caused to these drawbacks, and more of that, two improved schemes are also proposed which are free from worries of those possible attacks.