Paper 2019/094

CHES 2018 Side Channel Contest CTF - Solution of the AES Challenges

Aron Gohr and Sven Jacob and Werner Schindler

Abstract

Alongside CHES 2018 the side channel contest 'Deep learning vs. classic profiling' was held. Our team won both AES challenges (masked AES implementation), working under the handle AGSJWS. Here we describe and analyse our attack. We can solve the more difficult of the two challenges with $2$ to $5$ power traces, which is much less than was available in the contest. Our attack combines techniques from machine learning with classical techniques. The attack was superior to all classical and deep learning based attacks which we have tried. Moreover, it provides some insights on the implementation.