The part of signals intelligence (SIGINT) based on intercepting communications.
ODNI lists COMINT alongside ELINT and FISINT as components of SIGINT.1
The International Spy Museum defines COMINT as all intelligence gathered from intercepted communications. Conclusions can be drawn not only from the content: traffic analysis studies the patterns and volume of intercepted messages.2
Historical examples: the breaking of the Enigma cipher by the Polish Cipher Bureau and Britain's Ultra, and the American VENONA programme, in which, from February 1943, the Signal Intelligence Service examined Soviet diplomatic and intelligence correspondence. US–British cooperation in this field was formalised by the UKUSA agreement of March 1946, the nucleus of the Five Eyes alliance.3,4
Sources
- Office of the Director of National Intelligence (USA), What is Intelligence?
- International Spy Museum (Washington, DC), Language of Espionage (glossary)
- NSA, Declassified Documents: VENONA
- NSA/CSS, Declassified UKUSA Signals Intelligence Agreement Documents Available (press release), 24.06.2010
Checked: 4 November 2026