International Association
for Cryptologic Research

The idea of balancing the side-channel leakage in software was proposed more than a decade ago. Just like with other hiding-based countermeasures, the goal is not to hide the leakage completely but to significantly increase the effort required for the attack. Previous approaches focused on two directions: either balancing the Hamming weight of the processed data or deriving the code by using stochastic leakage profiling.

In this brief, we build upon these results by proposing a novel approach that combines the two directions. We provide the theory behind our encoding scheme backed by experimental results on a 32-bit ARM Cortex-M4 microcontroller. Our results show that such a combination gives better side-channel resistance properties than each of the two methods separately.