Efficient Mobile Authentication Scheme Preserving User Privacy for Large-Scale Wireless Networks

Most recently, Chang and Tsai proposed an anonymous and self-verified mobile authentication with authenticated key agreement for large-scale wireless networks. In this paper, we point out their scheme cannot provide user unlinkability, which is important to protect user privacy. Moreover, we find that if the delegation key of a mobile user is compromised, the identity of the user cannot be used any more. In addition, we also find it is not practical enough due to high computational cost involved. Thereafter, we propose a novel lightweight authentication scheme with anonymity and unlinkability for roaming service in large-scale wireless networks to overcome the foresaid defects. Moreover, we formally analyze our proposed scheme with the BAN-logic and show that it can withstand the several possible attacks.