A SPA Countermeasure for Hardware Implementation of SM2 Algorithm

SM2 algorithm is widely used in financial IC cards. It has the advantages of fast operation speed and short signature, but it may also contain security vulnerabilities. Attackers can crack the secret key via Simple Power Analysis (SPA), which is the inexpensive and extremely effective method, causing a great threat to the security of SM2 algorithm. In order to improve the safety of SM2 algorithm, this paper introduces atomic algorithm to implement point addition and point doubling operation, and proposes precomputed Non Adjacent Form (NAF) random window algorithm to achieve scalar multiplication. Based on experimental analysis with SAKURA-G FPGA board, the improved SM2 algorithm can resist successfully SPA. Compared with the original algorithm, the time of computation is reduced by 67.5%, and the number of slice registers has increased by less than 5%. The security and speed of SM2 algorithm has been significantly improved.