Optimality and Efficiency of Higher-Order Rank-Based Side-Channel Attacks against Inner Product Masking Schemes
HO-ASPA (Higher-Order Adjusted Spearman Coefficient Analysis) is a rank-based, non-profiling side-channel distinguisher. The paper derives its optimal form against two-share Boolean masking and inner product masking under Hamming weight and LSB leakage. It finds no significant gap between higher and lower orders for HO-ASPA, unlike HO-CPA, and reports that it beats Kruskal-Wallis-based attacks in simulated and real-world experiments.
Hardware & RFΒ· Added 31 Oct 2026, published 29 Oct 2026

