Security Analysis and Strengthening of an RFID Lightweight Authentication Protocol Suitable for VANETs

Abstract

Due to the storage capacity and computational power restrictions of low-cost RFID tags based on the EPC-C1G2 standard, most of the existing authentication protocols seem too complicated to be appropriate for these tags; thus the design of authentication protocols compliant with the EPC-C1G2 standard is a big challenge. Recently, a lightweight mutual authentication protocol for RFID conforming to the EPC-C1G2 standard was proposed by Caballero-Gil et al. aiming to be used in VANETs. This scheme does not rely on RFID readers as they are portable. Instead, it bases security on trust in the server because all shared secrets are stored only by the tag and the server with no possible access by the reader at any time. In this paper, we prove that this scheme is vulnerable to de-synchronization attack and suffers from the information leakage with a complexity of about 216 offline PRNG evaluations which is completely affordable by a conventional adversary. In addition, we present a simple tag impersonation attack against this protocol. To counteract such flaws, we improve the Caballero-Gil et al. scheme to present a new RFID authentication protocol, entitled CG+, so that it provides the claimed security properties. © 2015, Springer Science+Business Media New York.