摘要
S盒是分组密码中重要的非线性部件,S盒的密码性质直接影响了密码算法的安全性,一个好的S盒要求有较高的非线性度。William Millan曾给出一个能改善双射S盒非线性度的Hill Climbing算法,它通过交换S盒的两个输出向量来提高S盒的非线性度直到非线性度达到一个局部最优值,本文在此基础上研究了如何同时改变S盒的四个输出向量的位置来更大程度的提高S盒的非线性度。
A S-box is the important nonlinear conponent of block cipher, its cryptographic properties will affect the security of an algorithm, and a good S-box must be highly nonlinear. William Millian provided the Hill Climbing algorithm for improving the nonlinearity of bijective S-boxes, which can increase the nonlinearity of a bijective S-box by swapping two output vectors. By doing this, the nonlinearity will reach a local maximum. Based on Hill Climbing algorithm, we discuss a method which can improve the nonlin- earity of bijective S-boxes by changing the positions of four output vectors simultaneously.
出处
《微计算机信息》
北大核心
2007年第18期29-30,共2页
Control & Automation
基金
北京市自然科学基金资助项目(4063040)
北京电子科技学院科研基金项目(YZG200507)
