Power amount analysis: Another way to understand power traces in side channel attacks

Correlation power analysis, a method aiming to reveal the secrets of a cryptosystem, is based on one fixed time point of the captured power traces, which unveils the largest key dependent information leakage. In this paper, we propose a new power trace model based on communication theory to better understand and to efficiently exploit power traces in side channel attacks. Then, a new attack method denoted as Power Amount Analysis is proposed, which takes more time points into consideration compared to the correlation power analysis. Based on this trace model, we compare and discuss attack results produced by both methods at identical attack conditions. The superior efficiency of the Power Amount Analysis is demonstrated for an AES-128 encryption module. As an additional asset, this method features a high robustness in presence of randomly misaligned power traces.