SIMECK密码代数故障攻击研究

On algebraic fault attack against SIMECK cipher

针对SIMECK密码给出一种代数故障攻击方法。首先给出SIMECK加密轮函数和密钥生成策略等效代数方程创建方法;分别设定故障已知模型和故障未知模型,并在故障未知模型下提出基于故障注入差分和基于正确/故障密文差分确定故障索引值两种策略创建故障信息方程;利用基于SAT问题求解方程组。结果表明,在SIMECK32/64第24轮注入单比特翻转故障,故障已知模型和基于故障注入差分的故障未知模型均仅需两次注入即可恢复完整64bit主密钥;在第27轮注入故障,基于密文差分的未知模型需九次注入可恢复完整主密钥。与已有研究相比,该攻击密钥搜索复杂度更低,所需故障注入样本量更少。

This paper evaluated the security of SIMECK using the algebraic fault analysis. Firstly, it gave the method of creating equivalent algebraic equations of SIMECK encryption round function and key generation strategy. Secondly, it designed the known fault model and stochastic fault model respectively, and proposed two strategies based on the differential value of fault injected and the fault index determined by differential value of ciphertext to create equivalent equations of fault information under the unknown model. Finally, it solved equations based on the SAT problem. Experimental results show that after injecting single-bit fault to the 24th round of SIMECK32/64, the fault known model and the fault unknown model based on differential value of the fault injection, only 2 injections can recover the full 64 bit master keys. And 9 injections needed for the fault unknown model based on the differential value of ciphertext after injecting single-bit fault to the 27th round. The method's complexity of searching key is simpler and its fault injection sample required is less compared with the previous research.