Correlation Power Analysis Distinguisher Based on the Correlation Trace Derivative

Correlation power analysis (CPA) is one of the most common side channel attacks today, posing a threat to many modern ciphers, including AES. The simplest method to extract the correct key guess is selecting the guess with the maximum Pearson correlation coefficient. We propose another distinguisher based on a significant change in the correlation trace rather than on the absolute value of the coefficient. Our approach performs better than the standard CPA, especially in the noisy environment.