Security analysis of an RFID tag search protocol

• The security of the RFID tag search protocol proposed by Sundaresan et al. is analyzed.
• We challenge Sundaresan et al.'s claim about the robustness of their protocol against desynchronization and impersonation attacks.
• We also show that the protocol cannot preserve tag location privacy.

Over the past decade, tag search protocols have been suggested to efficiently acquire a specific RFID tag among a large group of tags by an RFID reader. For instance, in a warehouse, where there are thousands of packages each having an RFID tag attached, staffs may find specific packages using a reader that employs a tag search protocol. Although tag search protocols promise convenience, most of them can threaten the privacy of RFID tags in different ways. For instance, an attacker can impersonate a tag to replace it with another tag or can find the identity of a tag to track it. Recently, Sundaresan et al. have proposed an RFID tag search protocol based on 128-bit pseudo random number generators and exclusive-or operations which both can be easily implemented on low-cost RFID passive tags in EPC global Class-1 Gen-2 standard even for large-scale implementations. They claim that their protocol not only offers anonymity, location privacy and forward secrecy for the reader and the tag, but also resists against de-synchronization, replay and impersonation attacks. In this paper, we analyze the security of their proposed tag search protocol and show that the protocol is vulnerable to de-synchronization and impersonation attacks and also cannot provide location privacy for the tag.