## Comments on "Improved Efficient Remote User Authentication Schemes"

Das, Manik Lal
##### Description
Recently, Tian et al presented an article, in which they discussed some security weaknesses of Yoon et al's scheme and subsequently proposed two improved'' schemes. In this paper, we show that the Tian et al's schemes are insecure and vulnerable than the Yoon et al's scheme.
##### Keywords
Computer Science - Cryptography and Security