Communications security

communications security (COMSEC): Measures and controls taken to deny unauthorized persons information derived from telecommunications and ensure the authenticity of such telecommunications.

Note: Communications security includes cryptosecurity, transmission security, emission security, and physical security of COMSEC material. (a) cryptosecurity: [The] component of communications security that results from the provision of technically sound cryptosystems and their proper use. (b) emission security: Protection resulting from all measures taken to deny unauthorized persons information of value which might be derived from intercept and analysis of compromising emanations from crypto-equipment, AIS, and telecommunications systems. (c) physical security: The component of communications security that results from all physical measures necessary to safeguard classified equipment, material, and documents from access thereto or observation thereof by unauthorized persons. (d) transmission security: [The] component of communications security that results from the application of measures designed to protect transmissions from interception and exploitation by means other than cryptanalysis.

Source: from Federal Standard 1037C and from MIL-STD-188 and from the National Information Systems Security Glossary and from the Department of Defense Dictionary of Military and Associated Terms