An Efficient Anonymous Authentication Protocol for RFID Systems Using Dynamic Tokens

Radio frequency identification (RFID) technologies are widely used in many applications. The widespread use of tags in traditional ways of deployment raises a privacy concern: They make their carriers trackable. This paper studies the problem of anonymous authentication. Due to resource constraints of low-cost tags, we develop a new technique to generate dynamic tokens for anonymous authentication by following an asymmetric design principle that pushes most complexity to more powerful RFID readers. Instead of implementing complicated cryptographic hash functions, our authentication protocol only requires tags to perform several simple hardware-efficient operations such as bitwise XOR, one-bit left circular shift and bit flip. Moreover, our protocol reduces the communication overhead and online computation overhead to O(1) per authentication for both tags and readers, which compares favorably with the prior art.