PRESENT密码算法的差分电磁攻击研究

Research on Different Electromagnetic Attack on PRESENT Algorithm

利用改进的电磁攻击方式,在搭建的物理平台上通过电磁线圈探寻密码芯片表面的最佳探测区域进行差分电磁攻击,并同时对S盒和异或输出部分产生的电磁功耗进行差分分析。两部分的分析结果可互相印证或补充,从而高效地恢复出80 bit密钥中的64 bit。攻击者只需再对剩下的16 bit进行穷举攻击,即可完全破译PRESENT算法的80 bit密钥。在分析过程中,从均值差的峰值位置还可以判断出密码芯片对内部子密钥运作处理的顺序。此外,针对PRESENT原文算法描述中的一个小问题,给予了纠正。

In this paper, the PRESENT algorithm is analyzed by the improved electromagnetic attack. The sensitive areas are found through magnetic coil over cipher chip on physical experiment platform. Differential electromagnetic analysis is implemented on the output of S-box and that of XOR. The results of analysis are mutually supported and complemented. In this way, 64 bits of the 80 bit original key can be recovered efficiently. The other 16 bits can be recovered through exhaustive attack and then the 80-bit original key could be recovered. In the analysis process, the peak value of the difference between mean values leaks the information of sub-key operating order in cipher chip. Furthermore, a flaw in the original PRESENT algorithm description is pointed out and corrected.