对流密码Helix的代数故障攻击

Algebraic fault attack on Helix

对Helix流密码算法首次提出一种代数故障攻击方法。将代数攻击和差分故障攻击结合,对Helix算法中的模加运算结构提出了一种通用的代数故障攻击模型,通过选择明文和故障注入,构建了Helix在该模型下的代数方程组,使用CryptoMiniSAT解析器求解方程组系统恢复密钥信息。实验结果表明,580次故障注入即可恢复Helix工作密钥除最高位外的248比特信息,剩余8比特密钥信息可以通过穷举得到。针对模2n加运算所提出代数故障攻击模型可以为其他流密码安全性分析提供一定的参考。

An algebraic fault attack method on Helix is first proposed. The attack combines algebraic attack with differential fault attack, firstly a general model to attack the differential equations of addition is proposed. Secondly, the algebraic equation system of Helix under the model is built by choosing different plaintexts and inserting random faults. Finally, the key is recov- ered by solving the equation system with the CryptoMiniSAT solver. Experimental results show that it can recover the 248 bits of the working keys and the rest 8 bits can recovered by exhaustive research. The model can is applied to other stream ciphers with its versatility and solving conveniently.