SM4算法门限掩码方案设计与实现

侧信道分析已严重威胁到密码算法应用安全，为提高SM4算法抵御侧信道分析的能力，提出一种门限掩码方案。首先，完成对SM4算法S盒的复合域分解；其次，基于二共享设计门限掩码方案，使用随机数将S盒输入进行二共享拆分，通过复合域运算和S盒门限掩码进行电路重构，并基于S盒复用降低硬件开销；最后进行线性层操作后将两个输出结果通过异或完成去掩码操作。对SM4算法门限掩码方案的FPGA实现仿真结果和安全性测试结果表明，本掩码方案能够有效抵抗CPA攻击，实现面积相对较低。

Design and implementation of threshold masking schema on SM4 algorithm

Side channel analysis has seriously threatened the application security of cryptographic algorithms. In order to improve the ability of SM4 algorithm to resist side channel analysis, this paper proposed a threshold masking scheme for SM4 algorithm. Firstly, it decomposed the S-box of SM4 algorithm. Then this paper designed the threshold masking method based on two sharing pattern for SM4. According to the method, the schema split the S-box input into two shares by using random number, and rebuilt the circuit by S-box composite field operation and the S-box threshold masking, and reduced the hardware cost by reusing S-boxes. After the linear layer operation, the schema carried out unmasked operation by XOR the two output results. The simulation results and security test results of FPGA implementation for SM4 threshold masking schema show that the masking scheme can effectively resist CPA attack, and its implementation area is lower.