Attacks to a lightweight RFID mutual authentication protocol

In this paper, we analyze the security of the lightweight RFID mutual authentication protocol called the GA protocol. It is claimed that the GA protocol provides data confidentiality, integrity, tag anonymity and untraceability of tags and also prevents replay attacks, man-in-the-middle attacks as well as impersonating the parties. We show that an adversary that does not know the internal state of the tag can easily impersonate a tag to the valid back-end. Furthermore, we present server impersonation attack against the GA protocol in which an adversary that does not know the internal state of the tag can easily impersonate the valid back-end to valid tag. These attacks also break synchronization between back-end and tag.