基于复合域的SM4算法的设计与实现
Design and Implementation of SM4 Block Cipher Based on Composite Field
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摘要: 从S盒优化角度入手,提出一种基于复合域的S盒实现方式,通过同构映射矩阵,将GF(28)的有限域求逆运算变到GF(((22)2)2)的复合域上进行,从而降低了计算的难度,比查找表方式面积减小约27%.在此基础上,设计实现了整个SM4算法,基于smic0.13 μm的CMOS工艺综合显示,整个IP核面积仅为7 612门.本设计非常适用于智能IC卡等面积约束较严格的场合.Abstract: In this paper, a new method based on composite field is proposed. Through isomorphism bit matrices, the calculation by changing finite field inversion from GF(28) to GF(((22)2)2) is simplified to reduce the computational difficulty and a more compact S-box is realized. The area decreases by 27% than Look-up Table. On the basis of that, the SM4 algorithm is implemented. The area of this IP core is only 7 612 gates synthesized under the smic0.13 μmCMOS process. Therefore this improved design is very helpful for area-limited condition such as IC cards.