Abstract
This study will demonstrate both Juang's scheme and Shieh-Wang's scheme do not provide perfect forward secrecy and are vulnerable to a privileged insider's attack. Besides, their scheme has the problem of slow wrong password detection and user cannot change his password freely. To remedy these flaws, this study proposes an efficient remote mutual authenticated and key agreement scheme with perfect forward secrecy. The proposed scheme not only provides perfect forward secrecy but also satisfies all the security requirements needed in remote mutual authentication and key agreement scheme. © 2009 Asian Network for Scientific Information.