Enhanced Tower Field Mask Scheme with Affine Transformation-based Dynamic S-box

Masking countermeasures are robust solutions applied to cryptographic devices to improve their side-channel analysis resistance. Implementing substitution boxes (S-boxes) and using an efficient mask scheme are essential for improving security in modern ciphers. Consequently, this paper proposes an improved tower field mask scheme with an affine transformation-based dynamic S-box. The approach resists both Correlation Power Analysis attacks with Hamming Weight and Hamming Distance models, even when employing up to two million power traces. The measurement-to-disclosure improvement for the extracted key byte is at least 158× higher than the previous scheme, while our hardware overhead is around 1.04×. Furthermore, the proposal enhances the devices’ resistance to recent Deep-Learning Side-Channel Analyses.