technical surveillance countermeasures

Techniques and measures to detect and neutralize a wide variety of hostile penetration technologies that are used to obtain unauthorized access to classified and sensitive information. Technical penetrations include the employment of optical, electro-optical, electromagnetic, fluidic, and acoustic means as the sensor and transmission medium, or the use of various types of stimulation or modification to equipment or building components for the direct or indirect transmission of information meant to be protected. Also called TSCM. See also counterintelligence.