What type of filters are NOT required for TEMPEST purposes unless specifically recommended?

• A. Telephone line filters
• B. Power filters
• C. Non-conductive disconnects
• D. All of the above

Answer: (D)

In the context of TEMPEST (Telecommunications Electronics Material Protected from Emanating Spurious Transmissions), certain types of filters are generally not required unless there are specific recommendations for their use. This is based on the understanding that the primary focus is on shielding and safeguarding sensitive information from electronic surveillance and emanations.

Telephone line filters, power filters, and non-conductive disconnects are all types of filters that can serve protective purposes in different contexts. However, for standard TEMPEST compliance, the need for these filters may be contingent on specific risk assessments or recommendations rather than a blanket requirement.

For instance, telephone line filters might be useful in some situations where classified communications are conducted over phone lines, but they are not universally required for all TEMPEST environments. Similarly, power filters can address particular vulnerabilities in electrical systems, yet they too are not mandated in every case. Non-conductive disconnects play a role in ensuring that electrical connections do not compromise electromagnetic security, but again, their necessity often depends on the specifics of the situation being assessed.

In summary, the choice indicating that all three types of filters are not universally required aligns with TEMPEST principles, which prioritize specific assessments over general mandates for various protective measures. This