New Study Quantifies Timing Side-Channel Risks in Lattice-Based Post-Quantum Schemes

Global: New Study Quantifies Timing Side-Channel Risks in Lattice-Based Post-Quantum Schemes

A research team has introduced a scenario-based statistical risk model to evaluate timing side-channel leakage in post‑quantum cryptographic implementations. The study, posted to arXiv in December 2025, focuses on lattice‑based key‑encapsulation mechanisms (KEMs) such as Kyber, Saber and Frodo, and assesses how environmental noise influences distinguishability of secret‑dependent execution times.

Methodology Overview

The authors treat timing leakage as a problem of distributional distinguishability under controlled execution conditions. Synthetic traces are generated for two secret classes across three operational scenarios—idle, jitter‑induced, and loaded—and across multiple leakage models to simulate realistic measurement noise.

Statistical Metrics Employed

Leakage is quantified using Welch’s t‑test, Kolmogorov‑Smirnov (KS) distance, Cliff’s delta, mutual information, and distribution overlap. These indicators are combined in a TLRI‑like scoring framework to produce a consistent risk score that enables ranking of scenarios.

Scenario‑Based Results

Across the examined KEM families, idle conditions generally yield the highest distinguishability between secret classes. In contrast, jitter and loaded conditions increase variance and overlap among trace distributions, thereby reducing the effectiveness of statistical tests.

Leakage Sources and Risk Signals

The analysis identifies cache‑index and branch‑style leakage as the most pronounced risk contributors, producing the strongest signals in the employed metrics.

Performance‑Risk Relationship

Faster cryptographic schemes can exhibit higher peak risk under comparable leakage assumptions, suggesting that execution speed may amplify timing‑related vulnerabilities.

Design Implications

The proposed model enables reproducible early‑stage comparisons of post‑quantum implementations before platform‑specific validation, offering designers a quantitative tool to assess timing‑side‑channel exposure.

This report is based on information from arXiv, licensed under Academic Preprint / Open Access. Based on the abstract of the research paper. Full text available via ArXiv.