Polynomial multiplication algorithms such as Toom-Cook and the Number Theoretic Transform are fundamental building blocks for lattice-based post-quantum cryptography. In this work we present correlation power-analysis-based side-channel analysis methodologies targeting every polynomial multiplication strategy for all lattice-based post-quantum key encapsulation mechanisms in the final round of the NIST post-quantum standardization procedure. We perform practical experiments on real side-channel measurements, demonstrating that our method allows to extract the secret key from all lattice-based post-quantum key encapsulation mechanisms. Our analysis shows that the used polynomial multiplication strategy can significantly impact the time complexity of the attack.

Faults occur naturally and are responsible for reliability concerns. Faults are also an interesting tool for attackers to extract sensitive information from secure chips. In particular, non-invasive fault attacks have received a fair amount of attention. One easy way to perturb a chip without altering it is the so-called Electromagnetic Fault Injection (EMFI). Such attack has been studied in great depth, and nowadays, it is part and parcel of the state-of-the-art. Indeed, new capabilities have emerged where EM experimental benches are used to cryptanalyze chips. The progress of this “field” is fast, in terms ofreproducibility,accuracy, andnumber of use-cases. However, there is too little awareness about such advances. In this paper, we aim to expose the true harmfulness of EMFI (including reproducibility) to enable reasonable security quotations. We also analyze protections (at hardware/firmware/system levels) in light of their efficiency. We characterize the specificity of EM fault injection compared to other injection means (laser, glitch, probing).

This paper is the first to present an implementation of a cryptographic circuit in 28nm FD-SOI using near-threshold design. The implemented cipher, Ketje Jr, is a lightweight authenticated encryption algorithm. The energy consumption of representative authenticated encryption operations as well as the information leakage through the power consumption side-channel are evaluated. The results show that an ultra-low energy implementation can be achieved, and that the near-threshold design has little influence on the Signal to Noise Ratio in the power measurements of our chip.