Abstract: This paper examines the strength of CLEFIA block cipher against multiple bytes differential fault attack. It presents a principle of CLEFIA and differential fault analysis. According to inject faults into the rth, r-1th, r-2th round three conditions, it proposes a new fault analysis method on CLEFIA based on multiple bytes fault model, and verifies it through software simulation. Experimental result demonstrates that due to its Feistel structure and S-box feature, CLEFIA is vulnerable to multiple bytes fault attack, 6~8 faulty ciphertexts are needed to recover full 128 bit key.

Key words: block cipher, CLEFIA cipher, Feistel structure, multiple bytes faults, differential fault analysis

摘要： 研究CLEFIA分组密码对多字节差分故障分析的安全性，给出CLEFIA分组密码算法及故障分析原理。根据在第r轮、r-1轮、 r-2轮注入多字节故障的3种条件，提出一种新的针对CLEFIA的多字节故障模型及分析方法。通过仿真实验进行验证，结果表明，由于其Feistel结构和S盒特性，CLEFIA易遭受多字节故障攻击，6~8个错误密文可恢复128 bit的CLEFIA密钥。

关键词: 分组密码, CLEFIA密码, Feistel结构, 多字节故障, 差分故障分析

CLC Number: 

• TP309