Using HB Family of Protocols for Privacy-Preserving Authentication of RFID Tags in a Population

Abstract. In this paper, we propose an HB-like protocol for privacy-preserving authentication of RFID tags, whereby a tag can remain anonymous and untrace- able to an adversary during the authentication process. Previous proposals of such protocols were based on PRF computations. Our protocol can instead be used on low-cost tags that may be incapable of computing standard PRFs. Moreover, since the underlying computations in HB protocols are very e‐cient, our protocol also reduces reader load compared,to PRF-based protocols. We suggest a tree-based approach that replaces the PRF-based authentication from prior work with a procedure such as HB+ or HB#. We optimize the tree- traversal stage through usage of a \light version" of the underlying protocol and shared random,challenges across all levels of the tree. This provides signiflcant re- duction of the communication resources, resulting in a privacy-preserving protocol almost as e‐cient as the underlying HB+ or HB#.