On security of a remote user authentication scheme without using smart cards

He Debiao*, Chen Jianhua, Hu Jin School of Mathematics and Statistics, Wuhan University, Wuhan, Hubei 430072, China Abstract: The security of a password authentication scheme using smart cards proposed by Rhee et al. is analyzed. A kind of impersonation attack is presented. The analyses show that the scheme is insecure for practical application. In order to eliminate the security vulnerability, an efficient countermeasure is proposed.