Which of the following is NOT considered a TEMPEST countermeasure recommended by CTTA?

• A. The use of shielded enclosures
• B. The use of TEMPEST profiles for equipment
• C. The use of non-conductive disconnects for telephone lines
• D. RED and BLACK separation installation guidance

Answer: (C)

The correct choice refers to “non-conductive disconnects for telephone lines,” which is not recognized as a TEMPEST countermeasure recommended by the Committee on Technical and Tactical Assistance (CTTA). TEMPEST is concerned with protecting sensitive information from being compromised through electromagnetic emanations, and the measures typically involve shielding and separation of different types of data.

Shielded enclosures serve to block or reduce emissions that could be intercepted by unauthorized entities, making them a fundamental TEMPEST countermeasure. Similarly, TEMPEST profiles that guide the specification of equipment help ensure that devices meet necessary security standards to minimize emissions. RED and BLACK separation is a crucial principle in signal transmission, where RED refers to unencrypted signals and BLACK refers to encrypted signals, preventing leakage of sensitive data.

In contrast, using non-conductive disconnects does not directly address the concerns related to electromagnetic emissions. This approach is more applicable to electrical safety or basic communication continuity rather than to safeguarding against data interception, which is the primary focus of TEMPEST countermeasures.