International Journal of Network Security
The user authentication scheme is a useful mechanism for verifying the legitimacy of a remote user over insecure network environments. Recently, smart card-based user authentication schemes have been used in a wide range of applications, such as Internet commerce, electronic mail system and voice over Internet protocol. However, most existing authentication schemes cannot protect the privacy of the user's identity. Therefore, the dynamic ID-based user authentication scheme is proposed to overcome this drawback. In this paper, the authors analyze some security properties for recent dynamic ID-based user authentications.