SIGINT

:''For other uses, see Sigint (disambiguation).''
'SIGINT' stands for 'SIG'nals 'INT'elligence, which is intelligence-gathering by interception of signals, whether by radio interception or other means. As sensitive information is often encrypted, SIGINT often involves the use of cryptanalysis. However, traffic analysis—the study of who is signalling whom and in what quantity—can often produce valuable information, even when the messages themselves cannot be decrypted.

Contents

Branches

COMINT

ELINT

FISINT

History

List of notable SIGINT projects

Further reading

See also

External links

Branches

Being a broad field, SIGINT has many sub-disciplines. The three main ones are 'COM'munications 'INT'elligence (COMINT), 'EL'ectronic 'INT'elligence (ELINT), and 'F'oreign 'I'nstrumentation 'S'ignals 'INT'elligence (FISINT).

COMINT

COMINT (Communications Intelligence) is a sub-category of SIGINT that engages in dealing with messages or voice information derived from the interception of foreign communications. It should be noted that COMINT is commonly referred to as SIGINT, which can cause confusion when talking about the broader intelligence disciplines.

ELINT

Main articles: ELINT

ELINT refers to intelligence-gathering by use of electronic sensors. In other words, ELINT is the interception and analysis of electromagnetic signals of other countries including radar, radio, telephony, and microwave transmissions. Its primary focus lies on non-communications signals intelligence. ELINT data is usually highly classified information, and is protected as such.

FISINT

Main articles: FISINT

FISINT (Foreign instrumentation signals intelligence) is a sub-category of SIGINT, monitoring primarily non-human communication. Foreign instrumentation signals include (but not limited to) telemetry, beaconry, electronic interrogators, tracking or firing command systems, and video data links.

History

SIGINT became far more central to military (and to some extent diplomatic) intelligence generally with the mechanisation of armies, development of blitzkrieg tactics, use of submarine and commerce raiders warfare, and the development of practicable radio communications. For example, failure to properly protect its communications fatally compromised the Russian Army in its advance early in World War I and led to their disastrous defeat by the Germans under Ludendorff and Hindenburg at the Battle of Tannenberg. Similarly, the interception and decryption of the Zimmerman telegram was an important factor in the US decision to enter the War. British commanders' lack of ability to take seriously traffic analysis information from intercepts was instrumental in the failure to achieve more than they did at the Battle of Jutland, thus losing what might have been a major opportunity.
The use of SIGINT had even greater implications during World War II. Early on, Admiralty dismissal of SIGINT information (also traffic analysis in this instance) contributed to the loss of HMS ''Glorious'' in 1940. The Allied ability to intercept and decrypt the German Enigma "E Traffic" and Japanese Purple (Magic) traffic proved to be a great military advantage. The combined effort of intercepts and cryptanalysis for the whole of the British forces in WWII came under the code name "Ultra" managed from Government Code and Cypher School (Bletchley Park). Perhaps most dramatically, intercepts of Japanese naval communications yielded information that gave Admiral Nimitz the upper hand in the ambush that resulted in the Japanese Navy's defeat at the Battle of Midway, six months after the Pearl Harbor attack.

List of notable SIGINT projects

★ Ultra - World War II

★ Magic (cryptography) - WW II

★ Purple code - WW II

★ VENONA Project - 1950s

★ ECHELON - ongoing

★ Frenchelon - ongoing

★ Room 641A - ongoing

★ NSA call database - ongoing

Further reading

★ Bamford, James, ''Body of Secrets: How America's NSA and Britain's GCHQ eavesdrop on the world'' (Century, London, 2001)

★ West, Nigel, ''The SIGINT Secrets: The Signals Intelligence War, 1900 to Today'' (William Morrow, New York, 1988)

See also

★ List of intelligence gathering disciplines

★ Canadian Forces Intelligence Branch

★ HUMINT: Human intelligence

★ Communications security (COMSEC)

★ ELINT: Electronic intelligence

★ IMINT: Imagery intelligence

★ GEOINT: Geospatial Intelligence

★ Narus: SIGINT hardware manufacturer referred to in Hepting vs. AT&T

★ OSINT: Open Source Intelligence

★ U.S. Marine Corps Radio Reconnaissance

★ RAF Intelligence: Royal Air Force Intelligence Branch

★ Traffic analysis

★ Historical Electronics Museum

External links

★ http://www.nsa.gov/sigint/ - SIGINT Overview

★ http://www.nsa.gov/sigint/sigin00003.cfm - SIGINT FAQ

★ http://www.fas.org/spp/military/program/sigint/overview.htm

★ http://groups-beta.google.com/group/sigint - SIGINT Google Group

★ David Alan Jordan, Decrypting the Fourth Amendment: Warrantless NSA Surveillance and the Enhanced Expectation of Privacy Provided by Encrypted Voice over Internet Protocol - Boston College Law Review, Vol. 47, 2006