Complete Coherent Demodulation and Recovery of Spread Spectrum Clocking-Based Electromagnetic Information Leakage: Theory and Demonstration

Analyzing unintentional electromagnetic (EM) emissions from contemporary devices remains a significant challenge due to the difficulty of identifying potential sources of vulnerability within modern integrated circuit design and the limited research on critical leakage points. These challenges are particularly pressing in today’s information-driven society, where such emissions pose substantial security risks. To address this issue, this paper focuses on spread spectrum clocking (SSC) schemes employed in information visualization devices (IVDs), offering an in-depth analysis of the diverse characteristics of EM leakage and highlighting their associated risks. To convey our contributions, we introduce a novel model based on a modified Fourier series that accurately captures SSC-induced EM waves, enhancing the understanding of emissions from SSC-based devices. Additionally, we propose complete coherent demodulation (CCD), an advancement of the periodic nonuniform sampling (PNS) framework that resolves byproduct-phase terms. Our work further integrates parameterized demodulation with singular value decomposition (PD-SVD) to refine the analysis of modulated instantaneous frequency terms within EM leakage observed over significant distances. These contributions advance security assessments and strengthen electromagnetic resilience.