Cryptanalysis of EC-RAC, a RFID identification protocol

Abstract

At RFID'08, Lee et al. have proposed a RFID scheme based on elliptic curve cryptography. This scheme, called Elliptic Curve Random Access Control (EC-RAC) has been conceived in order to be implemented on an efficient security processor designed for RFID tags. The aim of this scheme is to enable a fast, secure and private identification scheme. Security arguments are given to prove that RFID tags implementing this scheme are neither traceable nor cloneable. We here show how tags can be tracked if one has eavesdropped the same tag twice and we show that a tag can be impersonated if it has been passively eavesdropped three times. We propose a new scheme based on a modification of the Schnorr scheme as efficient as the initial scheme. We prove that this scheme is zero-knowledge, sound against active adversaries. Moreover, our proposal is private under the Decisional Diffie-Hellman assumption. © 2008 Springer Berlin Heidelberg.