中文摘要：

针对高级加密标准（AES ）S-盒优化，提出了一种新的多因子公共项消除（CSE ）优化算法．多因子CSE算法通过对组合逻辑表达式中所含因子最多的公共项优先消除，以简化逻辑表达式，从而有效地减少S-盒电路结构中的GF （2＾4）域乘法逆电路和映射矩阵电路的面积和时延．结果表明，多因子CSE算法具有计算速度快，优化效率高的特点．优化后的S-盒组合逻辑电路采用0.18μm CMOS工艺，设计出的S-盒面积-延时积比目前最小面积和最短延时的S-盒组合逻辑电路分别减少了10.32％和19.64％．

英文摘要：

Aiming at the optimization of advanced encryption standard （AES） S-box ,a novel multiple-term common subex-pression elimination （CSE ） algorithm was proposed .In order to simplify the combinational logic expressions ,the common subex-pressions containing the most factors took priority to be eliminated in the proposed approach ,thus effectively reduced the area and latency of the GF （2^4 ） multiplicative inverse circuit and the isomorphic mapping circuit in S-box .The results show that the multi-ple-term CSE algorithm achieves high computation and optimization efficiency .The optimized S-box is implemented in 0 .18μm CMOS technology .Compared with the smallest S-box and the shortest delay S-box in the existing work ,the optimized S-box saves about 10 .32% and 19 .64% of the area-delay product separately .