Authentication and Key Agreement Protocols Preserving Anonymity

Abstract

Anonymity is a very important security feature in addition to authentication and key agreement features in communication protocols. In this paper, we propose two authentication and key agreement (AKA) protocols: the AKA protocol with user anonymity (UAP) and the AKA protocol with user and server anonymity (USAP). The proposed protocols have the following advantages: first of all, they preserve anonymity, which is a security feature that was ignored in most of the previously proposed AKA protocols; secondly, they exploit the difference in capabilities between resource constrained clients and highly resourceful servers and thus are suitable for wireless applications; thirdly, they resist known attacks; and finally, they perform better in terms of the number of messages and bits exchanged and computing time as compared to the previously proposed AKA protocols. For example, USAP preserves user and server anonymity, exchanges 3 messages with 1920 bits in total, and requires only 280 msec of processing time on the user side when implemented on Mitsubishis M16C microprocessor. Similarly, the UAP is scalable, preserves user anonymity, requires 440 msec, and exchanges 2560 bits.