A ROBUST AUTHENTICATION SCHEME WITH USER ANONYMITY FOR WIRELESS ENVIRONMENTS

Due to the openness of data transmission over wireless environments, the wireless networks are susceptible to various security menaces. Authentication and key agreement become a basic and most important procedure before a mobile user cart obtain the desired services. Apart from the security threats, in a limited bandwidth and the openness wireless environment, low computation and communication cost with privacy should be taken into considerations. Recently, Zhu and Ma proposed art authentication scheme with user anonymity for wireless environments based on hash functions and smart cards. In their scheme, the communication and computation cost is very low. However, Lee et al. pointed out that Zhu and Ma's scheme is vulnerable to several security problems. The perfect backward secrecy and mutual authentication are not provided and the forgery attack cart work in Zhu and Ma's scheme. At the same time, Lee et al. proposed art improvement to solve the above weaknesses and to keep the efficiency. However, in this paper, we show that. Lee et al.'s scheme cannot provide the anonymity for a mobile user and the key agreement procedure is not correct. Also, if a smart card is stolen by art adversary, the adversary could launch the impersonation attack on Lee et al.'s scheme. We then propose a new authentication scheme. Our scheme not only provides more security criteria but, also requires low communication and computation cost. Finally, we use the logic analysis method to prove our scheme.