AES加密算法的S-box设计分析及其改进

S-box Design and Analysis of AES Encryption Algorithm and Its Improvement

在AES密码设计中,S-box作为实现数据非线性置换的组件有重要地位,其安全性直接影响整个密码的安全性。分析了AES加密算法中S-box的设计原理及其循环迭代周期。指出S-box循环迭代周期都远远小于256的短周期,使AES存在着差分攻击的可能。提出了改进方案,并得到新的S-box。改进的S-box循环迭代周期扩大到256整个空间,提高了算法的安全性。

As a component to realize data nonlinear replacement,S-box plays an important role in the design of AES cipher,and its safety directly affects the safety of the whole cipher.This paper analyzed the design theory of S-box in the AES encryption algorithm and its iteration cycle.It was pointed out that the cycle iterative cycle of S-box,which was far less than 256,was short and defected.Such a defect made the AES subj ect to differential attacks.This paper presented an im-proved scheme and a new S-box whose iteration cycle was expanded to 256 of the entire space with better algorithm security.