What is the unclassified term for investigations concerning compromising emanations from data processing equipment?

The term that specifically pertains to investigations concerning compromising emanations from data processing equipment is known as "Emission security." This unclassified term refers to the measures and protocols in place to protect against unauthorized interception and exploitation of signals emanating from equipment, which could potentially divulge sensitive information.

Emission security deals with the unintended leakage of data through electromagnetic emissions, ensuring that this information is safeguarded against being intercepted by adversaries. While the other options relate to different aspects of information security, such as communication security focusing broadly on safeguarding communications or computer security pertaining to the protection of computer systems from threats, they do not specifically address the issue of emanations in the sense that emission security does. Hence, Emission security is the most accurate and relevant term for the scenario described.