Research on the Relationship between the Effect of DPA and Differential Sample Frequency

As present, Differential Power Analysis (DPA) attack sample the power consumption information of chips using an oscilloscope which sample frequency is much larger than system global clock speed. Through the simulation of the S-box circuit in Advanced Encryption Standard (AES) and differential analysis of power consumption data, we find that, when reached an amount, the sample frequency´s increasing has slight influence on the DPA. Yet when the sample frequency decreases, the cost data collected by the collection points tends to be random, which results in the correlation between the measurements of the power and the data being processed is not well revealed. Under the precondition of not impacting the effect of DPA, proper reduction in the sample frequency will not only compress the data but also increase the number of power trace. Thus the effect of the DPA is strengthened. Meanwhile, the cost of design the sampling system is reduced, which leaves more space for the improvement of the accuracy of the sampling system.