DeePar-SCA: Breaking Parallel Architectures of Lattice Cryptography via Learning Based Side-Channel Attacks

Abstract

This paper proposes the first deep-learning based side-channel attacks on post-quantum key-exchange protocols. We target hardware implementations of two lattice-based key-exchange protocols—Frodo and NewHope—and analyze power side-channels of the security-critical arithmetic functions. The challenge in applying side-channel attacks stems from the single-trace nature of the protocols: each new execution will use a fresh and unique key, limiting the adversary to a single power measurement. Although such single-trace attacks are known, they have been so far constrained to sequentialized designs running on simple micro-controllers. By using deep-learning and data augmentation techniques, we extend those attacks to break parallelized hardware designs, and we quantify the attack’s limitations. Specifically, we demonstrate single-trace deep-learning based attacks that outperform traditional attacks such as horizontal differential power analysis and template attacks by up to 900% and 25%, respectively. The developed attacks can therefore break implementations that are otherwise secure, motivating active countermeasures even on parallel architectures for key-exchange protocols.