Electromagnetic spying – TEMPEST Risks, analysis, validation and standards

The TEMPEST risk concerns the problem of electromagnetic anti-compromission, i.e. the electromagnetic leakage of confidential information and the capture of compromising signals associated with this information by ill-intentioned people.

The victims of this electromagnetic espionage are the users of confidential information processed in a civil or military operational system via electrical or electronic equipment. This information is transformed into compromising electrical signals in the equipment. Then, through the phenomena of electrical and electromagnetic coupling, these transformed signals leak outside a secure perimeter, and can be intercepted by hostile individuals.

After Part 1, which introduces the TEMPEST domain, Part 2 presents concrete examples of the risk of TEMPEST interception of confidential information.

Part 3 then describes the phenomenology of the TEMPEST risk in terms of the coupling topologies between confidential signals and leaks outside the security perimeter. Definitions of TEMPEST risk terms shared by experts in the field and in TEMPEST standards are given.

To reduce or eliminate these risks, parts 4 and 5 present the conduct of theoretical risk analyses and performance validations at system, subsystem and equipment level. These two parts present the TEMPEST engineering processes, methods and resources for study (calculations/simulations) and validation (tests/measurements).

Part 6 deals with the French and international standards that frame and guide the TEMPEST field.

Part 7 provides a comparative description of TEMPEST risks/activities and EMC risks/activities. This comparison shows that the TEMPEST field is part of the EMC field in the broadest sense; some of the TEMPEST resources, methods and standards are borrowed from the EMC world. In particular, TEMPEST skills and expertise mainly require qualifications and experience in EMC, as well as knowledge of radio and signal processing.

The acronyms used are listed at the end of the article.