Government Communications Headquarters

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(Redirected from GC&CS)

The Government Communications Headquarters (GCHQ) is a British intelligence agency responsible for providing signals intelligence (SIGINT) and information assurance. GCHQ provides the UK government and armed forces with signals intelligence as required under the guidance of the Joint Intelligence Committee in support of government policies. The Communications-Electronics Security Group (CESG) is the branch of GCHQ which works to secure the communications and information systems of government and critical parts of UK national infrastructure.

GCHQ was previously known as the Government Code and Cipher School (GC&CS) before 1946.

GCHQ is the responsibility of the UK Secretary of State for Foreign and Commonwealth Affairs.

1 Government Code and Cipher School (GC&CS)
2 After World War II
3 Post Cold War
4 ECHELON
5 Public Key Encryption
6 GCHQ and the constitution
7 Leadership
8 See also
9 References
10 External links

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Government Code and Cipher School (GC&CS)

In early 1919, twenty-five officers from the wartime signals intelligence organisations of the Navy (Room 40) and the Army (MI1b) were merged into a single agency, the Government Code and Cipher School (GC&CS) (a cover-name chosen by Victor Forbes of the Foreign Office <ref>Template:Cite book</ref> ). Alastair Denniston was appointed the operational head with the title of Deputy Director. Initially, GC&CS was under the control of the Admiralty, but later, with its focus on diplomatic traffic, was placed under the control of the Foreign Office in 1922.

In the 1920s, GC&CS was successfully reading Soviet Union diplomatic ciphers. However, the British government made details from the decrypts public prompting the Soviet to change their systems to more secure schemes, including the one-time pad, in 1927.

Before World War II, GC&CS was a relatively small department, and staff included Alastair Denniston, Oliver Strachey, Dilly Knox, John Tiltman, Edward Travis, Ernst Fetterlein, Josh Cooper and Hugh Foss.

During the Second World War, GC&CS was based largely at Bletchley Park, reading German Enigma machine ciphers amongst a large number of other systems. In 1940, GC&CS were working on the diplomatic codes and ciphers of 26 countries, tackling over 150 diplomatic cryptosystems.

GC&CS was renamed the "Government Communications Headquarters" in June 1946. <ref>Template:Cite book</ref>

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After World War II

GCHQ was at first based in London, but in 1953 Template:Fact moved to the outskirts of Cheltenham, setting up two sites there - Oakley and Benhall. It was not officially avowed until 1983. The following year GCHQ was the centre of a political row when the Conservative government of Margaret Thatcher prohibited its employees from joining a Trade Union. It was claimed that joining such a union would be in conflict with national security. The ban was eventually lifted by the incoming Labour government in 1997, with the Government Communications Group of the Public and Commercial Services (PCS) Union being formed to represent interested employees. <ref>Template:Cite web</ref> In 2000, a group of fourteen former GCHQ employees, who were sacked after refusing to give up their union memberships, were awarded £500,000 compensation from the government. <ref>Template:Cite news</ref>

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Post Cold War

Since 1994, GCHQ activities have been subject to scrutiny by Parliament's Intelligence and Security Committee.

Post-Cold War, the aims of GCHQ were set out by the Intelligence Services Act (1994).

At the end of 2003, GCHQ moved to a new 'doughnut' shaped HQ, at the time the second largest public sector building project in Europe with an estimated cost of £337 million. <ref>Template:Cite web</ref> The new building is the base for all of GCHQ's Cheltenham operations.

GCHQ gains its intelligence by monitoring a wide variety of communications and other electronic signals. For this a number of stations have been established in the UK and overseas which are run by the Composite Signals Organisation for GCHQ. The Composite Signals Organisation Station, at Morwenstow near Bude, Cornwall is directly subordinate to GCHQ. The listening stations are at Cheltenham itself, GCHQ CSO Morwenstow, GCHQ CSO Ascension Island, with the Americans at Menwith Hill, and the Columbia Annex (CANX).

In addition to SIGINT, GCHQ provides assistance to Government Departments on their own communications security. This task is given to the Communications-Electronics Security Group (CESG) of GCHQ. CESG is the UK national technical authority for information assurance, including cryptography. CESG does not manufacture security equipment, but works with industry to ensure the availability of suitable products and services, while GCHQ itself can fund research into such areas, for example to the Centre for Quantum Computing at Oxford University.

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ECHELON

GCHQ, in combination with the equivalent agencies in the United States (NSA), Canada (Communications Security Establishment) and Australia (Defence Signals Directorate) and otherwise known as the UKUSA group, is believed to be responsible for, among other things, the operation of the ECHELON system. Its capabilities are suspected to include the ability to monitor a large proportion of the world's transmitted civilian telephone, fax and data traffic.

The public spotlight fell on GCHQ in late 2003 and early 2004 following the sacking of Katharine Gun after she leaked a confidential email from agents at the American National Security Agency to GCHQ agents about the wire-tapping of UN delegates in the run-up to the 2003 Iraq war.

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Public Key Encryption

Early in the 1970s the asymmetric key algorithm was invented by a staff member Clifford Cocks, a mathematics graduate. This fact was kept secret until 1997.

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GCHQ and the constitution

GCHQ actually determined the scope of judicial review on prerogative (residual powers from common law) in a very controversial case. This occurred in "Council of Civil Service Unions v Minister for the Civil Service [1985] AC 347". In this case, a prerogative order in council was used by the Prime minister to ban trade union activities by civil servants working at GCHQ. This order was issued without consultation. The House of Lords had to decide whether this was reviewable by Judicial Review. It was held that executive action is not immune from Judicial Review because it is carried out in the pursuit of power derived from common law. (i.e. prerogative is reviewable). Controversially, they also held that though the failure to consult was unfair, it was overriden by concerns of national security.

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