Comments on the SM2 key exchange protocol

Abstract

SM2 key exchange protocol is one part of the public key cryptographic algorithm SM2 which has been standardized by Chinese state cryptography administration for commercial applications. It became publicly available in 2010 and since then it was neither attacked nor proved to be secure. In this paper, we show that the SM2 key exchange protocol is insecure by presenting realistic attacks in the Canetti-Krawczyk model. The demonstrated attack breaks session-key security against an adversary who can only reveal session states. We also propose a simple modification method to solve this problem. © 2011 Springer-Verlag.