Enhanced Side-Channel Analysis on ECDSA Employing Fixed-Base Comb Method

Table-based scalar multiplication provides practical security for ECDSA signature generation. However, a novel key recovery attack against this form of generation that exploits the collisions between entries was recently proposed at CHES 2021. This is possible even if table are unknown, such as with random permutated entry ordering. In paper, we enhance efficiency secure based on fixed-base comb multiplication. We significantly reduce required number traces by compressing collision information using mathematical relationship collisions. verify threat performing an experiment method window width $w=4$. Using our method, up to 27 needed, much fewer than 1,019 in publication. cluster real measured 32-bit STM32F4 microcontroller. experiment, provide selection points interest variance and unsupervised clustering-based leakage detection. With succeed clustering leakages into 16 classes 100% success rate MCU. represents first more MCU literature.