针对随机时间片对抗的PA分析方法研究

Research of Power Analysis Against the Random Clock Countermeasure

在抗功耗分析的实际应用中,随机时间片作为一种常见的对抗方法,具有安全性高和开发成本低的优点.本文针对现有随机时间片下的攻击方法普遍具有的复杂度较高,以及通用性较低的问题,提出两种新型的PA(power analysis)攻击方法,即当量法和相关性法.这两种方法分别通过对不同单位周期的功耗以及相关性的比较对功耗曲线进行分析,以较小的代价确定目标轮次所在位置,并对曲线进行对齐操作,实现有效的功耗分析.与已有攻击方法的比较,以及实验结果均表明这两种攻击方法能以较低分析复杂度和较少分析样本,对工业级密码芯片中普遍采用的以时钟周期为插入单位的随机时间片对抗方法进行有效攻击.

Considering the balance between security and cost,the random delay countermeasure has been a common method in the application.In this paper,on the question of the high complexity and low generality of the existing methods,we propose two power analysis methods aimed at determining the location of the target round by comparing the value and correlation of one cycle with the others to achieve effective power analysis.Comparing with the existing methods,we show that the random delay countermeasure based on the clock period is unsafe,which can easily be attacked at lower complexity with fewer samples.