中文摘要：

SMS4算法是用于无线局域网产品的分组密码算法，本文研究对SMS4密码算法的差分功耗分析攻击方法．通过对算法结构的分析，结合差分功耗分析技术的原理．提出一种面向轮密钥字节的攻击方法．在利用该方法获取最后四轮轮密钥的基础上，即可进一步推算出128bit加密密钥．仿真实验结果证明，该攻击方法对SMS4轮运算有效可行，SMS4算法对差分功耗分析攻击是脆弱的，密码硬件设备需要对此类攻击进行防护．

英文摘要：

SMS4 algorithm is a block cipher used in WLAN products. In this paper, the differential power analysis attack on SMS4 algorithm is discussed. Based on analyses of the algorithm structure and principles of differential power analysis technologies, an attack method on every byte of round keys is presented. Through this attack, the round keys of the last four rounds of SMS4 can be obtained, and then the 128bit encryption key can be found out. The results of simulation experiments indicate that this attack method is effective and practical on SMS4 round operation. SMS4 algorithm is vulnerable to differential power analysis attacks, and cryptographic devices should be protected to prevent this kind of attacks.