A Novel SPA Attack on SM2 with Regular Point Multiplication

Compared with the RSA, the shorter key length is needed in the same security strength, so SM2 is more suitable for the application to the resource limited smart card. For the security of application of SM2, people study the variety point multiplication algorithms with countermeasures to resist the side channel attacks. This paper proposes a new simple side-channel analysis (SPA) method based conditional subtraction to attack two usual SM2 algorithms with countermeasures. Experimental results show that this method only needs a power trace, which can be used to break the SM2 key in a few seconds. At the same time, this paper also demonstrates some countermeasures to resist the attack.