针对AES分组密码S盒的差分故障分析

Differential Fault Analysis of AES Block Cipher Base on S-box

研究了AES分组密码对差分故障攻击的安全性,攻击采用面向字节的随机故障模型,结合差分分析技术,通过在AES第8轮列混淆操作前导入随机单字节故障,一次故障导入可将AES密钥搜索空间由2128降低到232.3,在93.6%的概率下,两次故障导入无需暴力破解可直接恢复128位AES密钥.数学分析和实验结果表明:分组密码差分S盒取值的不完全覆盖性为差分故障分析提供了可能性,而AES密码列混淆操作良好的扩散特性极大的提高了密钥恢复效率,另外,本文提出的故障分析模型可适用于其它使用S盒的分组密码算法.

This paper examines the strength of AES block cipher against the differential fault attack. The attack applies the byte-oriented fault model and combines the differential analysis method, after injecting one byte single fault into the 8th round of AES encryption before the MixColumns function, one faulty ciphertext is able to reduce AES key searching space from 2128 to 232.3, two faulty ciphertexts can extract the full 128-bit AES key without any brute-force search with about 93.6% probabilities. Mathematical analysis and experiments demonstrate that： the non-full coverage feature of the block cipher differential S box provides the probabilities of differential fault analysis, and the great diffusion property of AES MixColumns function greatly improves the attack efficiency of key recovering, meanwhile, the fault analysis model proposed in this paper can be applied into the fault analysis of other block ciphers with S-box.