Cryptanalysis of a modified remote user authentication scheme using smart cards
Kai-Chi Leung, L.M. Cheng, Anthony S. Fong, Chi-Kwong Chan · IEEE Transactions on Consumer Electronics · 2003
In this paper, the security of a modified remote user authentication scheme proposed by Shen, Lin, and Hwang is analyzed. We show that the modified scheme is still vulnerable to the attack proposed by Chan and Cheng. Moreover, the extended attack proposed by Chang and Hwang in 2003 also works well.