International Association
for Cryptologic Research

Template Attacks are widely accepted to be the most powerful side-channel attacks from an information theoretic point of view. For Template Attacks to be practical, one needs to choose some special samples as the interesting points in actual power traces. Up to now, many different approaches were introduced for choosing interesting points for Template Attacks. However, it is unknown that whether or not the pervious approaches of choosing interesting points will lead to the best classification performance of Template Attacks. In this work, we give a negative answer to this important question by introducing a practical new approach which has completely different basic principle compared with all the pervious approaches. Our new approach chooses the point whose distribution of samples approximates to a normal distribution as the interesting point. Evaluation results exhibit that Template Attacks based on the interesting points chosen by our new approach can achieve obvious better classification performance compared with Template Attacks based on the interesting points chosen by the pervious approaches. Therefore, our new approach of choosing interesting points should be used in practice to better understand the practical threats of Template Attacks.