基于抵抗故障引入攻击的RC4算法的改进

由Adi Shamir提出的故障引入攻击是目前破解RC4算法的非常有效的方法,其攻击的目标是RC4的伪随机生成阶段。为了抵抗这种攻击,增加伪随机生成阶段的安全性是十分有效的解决方案。本文提出了两种改进方案,其思想是在原算法的伪随机生成阶段中加入行移位和列移位过程,使其非线性变换更复杂。在对改进算法的正确性、安全性以及使用故障引入攻击破解改进算法的效率进行分析之后,证明了攻击者用故障引入攻击破解RC4算法的效率低于穷举攻击,可以抵抗故障引入攻击。对两种改进算法的效率和安全性进行比较,改进算法1更有效率,改进算法2更安全。

Improvements against fault induction attack for RC4 algorithm

The Fault Induction Attack(FIA) proposed by Adi Shamir is an effective method in cracking RC4 algorithm.The target of the FIA is the Pseudo-Random Generation(PGR) phase of the RC4 algorithm.To resist this attack,it is necessary to enhance the security of the PGR phase.This paper presents two improvements that make the nonlinear transformation more complex by adding the row shift and column shift to the PGR phase.After analyzing the validity,security and the efficiency of the FIA,it is demonstrated that the efficiency of using FIA is lower than using exhaustive attack,which means that the improvements could resist FIA.Comparison of the two improvements shows that the first improvement is more efficient and the second improvement is more secure.