Abstract:

Aiming at the deficiency of CROP protocol, an improved ownership transfer protocol is proposed in this paper. In order to resist the inner reader impersonation attack, the improved scheme adds new storage information to the cloud, which introduces the current reader’s shared key for Hash encryption to ensure the key confidentiality. In the tag authentication information, the random numbers generated by the current and new reader are added to perform the pseudo random function and the quadratic residue encryption to resist tag impersonation and reader tracing attacks. To solve the de-synchronization attack, the reader simultaneously stores the updated and un-updated key to ensure synchronization between the reader and the tag. Using the quadratic residue theorem to encrypt the index to ensure the current reader can use the index quickly retrieve the legal tag and improve the authentication efficiency. Based on the Vaudenay privacy model, this paper proves the improved scheme satisfies the privacy performance of strong forward as well as backward un-traceability and can resist inner reader impersonation, de-synchronization, tag impersonation attacks and other security risks. The experimental results show that the improved scheme effectively reduces the reader’s authentication time. Compared with the existing protocols, this paper improves the scalability of the protocol while satisfying the secure ownership transfer.

Key words: RFID, ownership transfer protocol, quadratic residue theorem, Vaudenay privacy model