Abstract: At present, due to the problem of computation，traditional side channel analysis attacks of SM4 algorithm both at home and abroad recover the key primarily by isolating S-boxes and breaking them one by one. This traditional method requires a large number of measured power consumption curves because it does not fully utilize the key-related information in the power consumption curve, resulting in waste of information. To overcome limitation of traditional method, a smart side channel analysis attack method for SM4 algorithm is proposed. This method regards the four S-boxes in SM4 algorithm as a whole, and uses the power of multiple S-boxes to reveal information. The key is quickly searched by a hybrid algorithm combining PSO and GA. Comparison experiments of key recovery between the two methods show significant decrease in the number of measured power curves required to recover the first round key of S-boxes of SM4 algorithm, from 1,670 in the traditional method to only 790 in the new method. It proves that the new method can reduce the number of measured power curved needed to recover SM4 algorithm key as well as improve the efficiency of side information trace analysis attack.

Key words: SM4, side channel analysis attacks, S-box, hybrid intelligent algorithms, power curve

摘要： 目前国内外针对SM4算法的传统侧信道分析攻击，由于计算量问题，采取将S盒隔离，逐个攻破的方式进行密钥恢复。该方式无法利用功耗曲线中与密钥相关的全部信息，造成信息浪费、所需实测功耗曲线数量多等问题。针对传统方式的局限性，提出一种针对SM4算法的混合智能侧信道分析攻击方法。该方法将SM4算法中的4个S盒视为一个整体，同时利用多个S盒的功耗泄露信息，通过PSO与GA相结合的混合算法快速搜索密钥。对传统和该方法进行密钥恢复对比实验，通过实验结果可知，恢复SM4算法S盒第一轮轮密钥传统分析方法需1 670条实测功耗曲线，而该方法仅需790条，验证该方法能够减少恢复SM4算法密钥所需实测功耗曲线数量，提高侧信道分析攻击效率。

关键词: SM4, 侧信道分析攻击, S盒, 混合智能算法, 功耗曲线