EMI Shielding for Use in Side-Channel Security: Analysis, Simulation, and Measurements

Considering side-channel analysis (SCA) security for cryptographic devices, the mitigation of electromagnetic (EM) leakage and EM interference (EMI) between modules poses significant challenges. This article presents a comprehensive review and deep analysis of the utilization of EMI shielding materials, devised for reliability purposes and standards such as EMI/EMC, as a countermeasure to enhance EM-SCA security. We survey the current landscape of EMI shields materials, including conductive polymers, metal-foams, carbon-based materials, and meta-materials, evaluating their effectiveness in attenuating emissions and preventing information leakage, a task done with security-centric metrics for such materials for the first time. Through a systematic examination of existing literature, experimental studies and a construction of fully simulatable EM environment in ANSYS-solver, we identify key factors influencing the performance of EMI shield materials, such as shielding-effectiveness (SE), bandwidth, thickness, and material properties, on security characteristics. We devise a connection between SE and cryptographic-SNR, and we demonstrate from real hardware measurements how and in what conditions can such materials provide very high security levels. By synthesizing insights from multidisciplinary research domains, this article aims to provide valuable two-way benefit and guidance for researchers, engineers, and practitioners in the design and deployment of robust side-channel security measures leveraging EMI shields, already in utilization devised by reliability standards.