Title: Physical Side-Channel Vulnerability Assessment of Traditional and Post-Quantum Cryptographic Schemes

Committee: 

Dr. Arijit Raychowdhury, Advisor

Dr. Justin Romberg, Chair

Dr. Suman Datta

Abstract: 

The objective of the proposed research is to better analyze physical side-channel vulnerabilities, with a specific focus on power and electromagnetic (EM) side-channels of the software and hardware implementations of traditional and Post-Quantum Cryptographic (PQC) schemes. While performing side-channel analysis (SCA) of such implementations, the recent body of works focused on proposing better Neural Network (NN) models to achieve higher accuracy at recovering the secret information (i.e., key or message), which is why, portability (profiling and attacking different devices running the same implementation) and interpretability (how the leakages are learned) issues of the NN models were largely overlooked. In the first part of the proposal, we demonstrate how this portability issue manifests itself in the NN-based power/EM SCA on a software implementation of Advanced Encryption Standard (AES)-128, and we propose an efficient cross-device attack using Multi-Device Training and Principal Component Analysis (PCA)-based pre-processing of traces under practical settings, as well as show how we can mitigate the effect of location-dependent Signal-to-Noise Ratio (SNR) of EM traces by automated probe positioning. In the second part of this proposal,  interpretability of NN models used in SCA is investigated to gain insight into which trace samples contribute the most to the classification decision, by validating the relevance scores of features (i.e., points or samples) derived from the NN models using gradient-based post-hoc explanation methods to the ones obtained by traditional Points-of-Interest (PoI) selection methods. In the last part of the proposal, we present preliminary studies conducted on a software implementation of a PQC Public Key Encryption (PKE)/Key Encapsulation Mechanism (KEM) scheme, namely, SABER, using correlation analysis and Test-Vector Leakage Assessment (TVLA) techniques, as well as, an ASIC design of a common compute block used in many Lattice-based PQC schemes and Fully Homomorphic Encryption (FHE) schemes, namely, Number Theoretic Transform (NTT) in a 65-nm technology. We propose to utilize the aforementioned techniques to perform SCA on implementations of these schemes and apply interpretability of NN models to the case of portability issue and novel vulnerability identification.