Abstract
Compromising electromagnetic emanations (CEME) represent a practical side-channel through which information processed by electronic equipment may be inferred from unintended radiated or conducted emissions. Modern digital systems—characterized by dense interconnections, switching power converters, and high-speed I/O—create a broad spectrum of emission mechanisms that are difficult to predict and control late in the design cycle. This paper provides an engineering review of the TEMPEST threat model, the standards and certification ecosystem used in governmental environments, and countermeasures spanning architecture, layout, shielding, bonding and grounding, and filtering. Emphasis is placed on mapping mitigation strategies to dominant coupling paths through zoning, RED/BLACK separation, and interface hardening. A practical verification workflow is proposed to link early design decisions to test evidence.