Reference-Free Spectral Analysis of EM Side-Channels for Always-on Hardware Trojan Detection

TL;DR

This paper introduces a reference-free spectral analysis method using EM side-channel signals and Gaussian Mixture Models to detect hardware Trojans in microelectronics, eliminating the need for trusted reference signals.

Contribution

The paper proposes a novel reference-free spectral analysis technique combining time-frequency EM analysis with GMMs for hardware Trojan detection.

Findings

Effective detection of HTs without reference models.

Persistent footprints of HTs identified through spectral analysis.

Feasibility demonstrated on AES-128 hardware.

Abstract

Always-on hardware Trojans (HTs) pose a critical risk to trusted microelectronics, yet most side-channel detection methods rely on unavailable golden references. We present a reference-free approach that combines time-frequency EM analysis with Gaussian Mixture Models (GMMs). By applying Short-Time Fourier Transform (STFT) at multiple window sizes, we show that HT-free circuits exhibit fluctuating statistical structure, while always-on HTs leave persistent footprints with fewer, more consistent mixture components. Results on AES-128 demonstrate feasibility without requiring reference models.