Information Theoretic Evaluation of Side-Channel Resistant Logic Styles

Abstract. We propose to apply an information theoretic metric to the evaluation of side-channel resistant logic styles. Due to the long design and development time required for the physical evaluation of such hard-ware countermeasures, our analysis is based on simulations. Although they do not aim to replace the need of actual measurements, we show that simulations can be used as a meaningful first step in the validation chain of a cryptographic product. For illustration purposes, we apply our methodology to gate-level simulations of different logic styles and stress that it allows a significant improvement of the previously consid-ered evaluation methods. In particular, our results allow putting forward the respective strengths and weaknesses of actual countermeasures and determining to which extent they can practically lead to secure imple-mentations (with respect to a noise parameter), if adversaries were pro-vided with simulation-based side-channel traces. Most importantly, the proposed methodology can be straightforwardly adapted to adversaries provided with any other kind of leakage traces (including physical ones).