Seil Kim, Ji Young Chun, Dong-Hoon Lee. Cryptanalysis of Two Improved Remote User Authentication Schemes Preserving User Anonymity. In Proceedings of the 9th International Conference for Young Computer Scientists, ICYCS 2008, Zhang Jia Jie, Hunan, China, November 18-21, 2008. pages 2235-2239, IEEE Computer Society, 2008. [doi]