A Set of Efficient Privacy Protection Enforcing Lightweight Authentication Protocols for Low-Cost RFID Tags

Providing security and privacy protection in Radio Frequency IDentification (RFID) tags is a challenging task due to their highly constrained resources. Because tags cannot support strong cryptography, security must rely on low-computational solutions. Privacy protection is often an additional requirement for acceptance of the technology by end-users. Thus, dedicated lightweight algorithms and protocols need to be designed. In this paper, we propose a set of extremely lightweight (optionally mutual) authentication protocols between a tag and a database (sharing a secret value) which protect the identity of the tag. However, if, for some practical reasons, the identity of the tag needs to be revealed to the reader, an additional optional last step can be added at the end of our protocols to satisfy this requirement. Our proposals are inspired by a protocol of Chien et al. but they are more efficient, since they operate in O(1) at database side, whilst covering security flaws and enforcing privacy protection. We examine the adequacy of our solutions regarding the chosen security requirements and their strengths against some well-known and more exotic attacks.