View source for Government Communications Headquarters

{{distinguish|Her Majesty's Government Communications Centre}}
{{Use dmy dates|date=April 2012}}
{{Use British English|date=April 2012}}
{{Infobox Government agency
|agency_name = Government Communications Headquarters
|nativename = 
|nativename_a =
|nativename_r =
|logo = Government Communications Headquarters logo.svg
|logo_width = 296px
|logo_caption = 
|seal = 
|seal_width = 
|seal_caption =
|formed = 1919 as the [[#Government Code and Cypher School (GC&CS)|GC&CS]]
|preceding1 = [[MI1b]]<small> (Army)</small>
|preceding2 = [[NID25]]<small> (Royal Navy)</small>
|dissolved =
|superseding =
|jurisdiction = [[Her Majesty's Government]]
|headquarters = [[The Doughnut]], [[Cheltenham]], [[UK]]<br/>{{Coord|51|53|58|N|2|07|28|W|display=inline}}
|employees = {{formatnum:6132}}<small> (fy 2012–13)</small><ref name=ISC_2012-2013>{{cite book|url=http://www.official-documents.gov.uk/document/hc1314/hc05/0547/0547.pdf|title=Intelligence and Security Committee of Parliament Annual Report 2012–2013|year=2013|accessdate=29 December 2013|isbn=978-0-10-298652-5|page=40}}</ref>
|budget = [[Single Intelligence Account (United Kingdom)|Single Intelligence Account]]
|minister1_name = [[Philip Hammond]]
|minister1_pfo = [[Secretary of State for Foreign and Commonwealth Affairs|Foreign Secretary]]
|minister2_name =
|minister2_pfo =
|chief1_name = [[Robert Hannigan]]
|chief1_position = [[Director of the Government Communications Headquarters|Director of GCHQ]]
|chief2_name =
|chief2_position =
|child1_agency =
|child2_agency =
|website = {{url|www.gchq.gov.uk}}
|footnotes =
}}
[[File:GCHQ-aerial.jpg|thumb|301px|"[[The Doughnut]]", the headquarters of the GCHQ.]]
The '''Government Communications Headquarters''' ('''GCHQ''') is a British [[intelligence agency|intelligence]] and [[security agency|security]] organisation responsible for providing [[signals intelligence]] (SIGINT) and [[information assurance]] to the [[Her Majesty's Government|British government]] and [[British Armed Forces|armed forces]].<ref>[http://www.gchq.gov.uk/who_we_are/Pages/Welcome-to-GCHQ.aspx GCHQ – Welcome to GCHQ], gchq.gov.uk. Retrieved 7 July 2014.</ref> Based in "[[The Doughnut]]", in the suburbs of [[Cheltenham]], it operates under the formal direction of the [[Joint Intelligence Committee (United Kingdom)|Joint Intelligence Committee]] (JIC) alongside the [[MI5|Security Service]] (MI5), the [[Secret Intelligence Service]] (MI6) and [[Defence Intelligence]] (DI). GCHQ is the responsibility of the UK [[Secretary of State for Foreign and Commonwealth Affairs]], but it is not a part of the [[Foreign Office]] and its Director ranks as a [[Permanent Secretary]].

GCHQ was originally established after the First World War as the ''Government Code and Cypher School'' (GC&CS) and was known under that name until 1946. During the Second World War it was located at [[Bletchley Park]], where it was famed for its role in the breaking of the German [[Enigma machine|Enigma codes]]. Currently there are two main components of the GCHQ, the Composite Signals Organisation (CSO), which is responsible for gathering information, and the CESG, which is responsible for securing the UK's own communications. The Joint Technical Language Service (JTLS) is a small department and cross-government resource responsible for mainly technical language support and translation and interpreting services across government departments. It is co-located with GCHQ for administrative purposes.

In 2013, GCHQ received considerable media attention when the former [[National Security Agency]] contractor [[Edward Snowden]] revealed that the agency was in the process of collecting all online and telephone data in the UK via the [[Tempora]] programme.<ref>{{Cite web|url = http://www.wired.co.uk/news/archive/2013-06/24/gchq-tempora-101|title = A simple guide to GCHQ's internet surveillance programme Tempora|date = |accessdate = |website = |publisher = |last = |first = }}</ref> Snowden's revelations began a spate of ongoing [[Global surveillance disclosures (2013–present)|disclosures of global surveillance]].

==Structure==
GCHQ is led by the Director of GCHQ, currently [[Robert Hannigan]], and a Corporate Board, made up of Executive and Non-Executive Directors. Reporting to the Corporate Board is:<ref>Aldrich, 2010, p. 565</ref><ref name="Leong">(secondary) {{cite book |url=http://books.google.com/?id=bnEk6zmoR0MC&pg=PA87&dq=Government+Communications+Headquarters#v=onepage&q=Government%20Communications%20Headquarters&f=false |first=Angela |last=Leong |title=The Disruption of International Organised Crime: An Analysis of Legal and Non-Legal Strategies |year=2007 |publisher=Ashgate Publishing |accessdate=19 April 2012|isbn=0-7546-7066-X }}</ref> 
:
*Sigint missions: comprising maths and [[cryptanalysis]], IT and computer systems, linguistics and translation, and the intelligence analysis unit
*Enterprise: comprising applied research and emerging technologies, corporate knowledge and information systems, commercial supplier relationships, and [[biometrics]]
*Corporate management: enterprise resource planning, [[human resources]], internal audit, and architecture
*Communications-Electronics Security Group

==History==
{{anchor|Government Code and Cypher School}}

===Government Code and Cypher School (GC&CS)===
During the First World War, the United Kingdom's [[British Army|Army]] and [[Royal Navy|Navy]] had separate signals intelligence agencies, [[MI1b]] and [[Room 40|NID25]] (initially known as Room 40) respectively.<ref>{{cite book |first=Paul |last=Gannon |title=Inside Room 40: The Codebreakers of World War I |publisher=Ian Allen Publishing |year=2011 |isbn=978-0-7110-3408-2}}</ref><ref>Johnson, 1997, p. 27</ref> In 1919, the Cabinet's Secret Service Committee, chaired by [[Lord Curzon]], recommended that a peace-time codebreaking agency should be created, a task given to the then-[[Naval Intelligence Division (UK)|Director of Naval Intelligence]], [[Hugh Sinclair]].<ref name="johnson44">Johnson, 1997, p. 44</ref> Sinclair merged staff from NID25 and MI1b into the new organisation, which initially consisted of around 25–30 officers and a similar number of clerical staff.<ref>Johnson, 1997, p. 45 and Kahn, 1991, p. 82; these sources give different numbers for the initial size of the GC&CS staff</ref> It was titled the "Government Code and Cypher School", a cover-name chosen by Victor Forbes of the [[Foreign Office]].<ref>{{Cite book|last=Macksey|first=Kenneth|title=The Searchers: How Radio Interception Changed the Course of Both World Wars|year=2003| publisher=Cassell Military|isbn=0-304-36545-9|page=58}}</ref> [[Alastair Denniston]], who had been a member of NID25, was appointed as its operational head.<ref name="johnson44"/> It was initially under the control of the [[Admiralty]], and located in Watergate House, Adelphi, London.<ref name= "johnson44"/> Its public function was "to advise as to the security of codes and cyphers used by all Government departments and to assist in their provision", but also had a secret directive to "study the methods of cypher communications used by foreign powers".<ref>Smith, 2001, pp. 16–17</ref> GC&CS officially formed on 1 November 1919,<ref>Kahn, 1991, p. 82</ref> and produced its first decrypt on 19 October.<ref name="johnson44"/>

[[Image:Allidina-Visram.jpg|thumbnail|left|200px|Allidina Visram school in Mombasa, pictured above in 2006, was the location of the British "Kilindini" codebreaking outpost during World War II]]

Before the Second World War, GC&CS was a relatively small department. By 1922, the main focus of GC&CS was on diplomatic traffic, with "no service traffic ever worth circulating"<ref name="agd">{{cite journal |first=Alastair G. |last=Denniston |title=The Government Code and Cypher School Between the Wars |journal=Intelligence and National Security |volume=1 |issue=1 |pages=48–70 |year=1986 |doi=10.1080/02684528608431841 }}</ref> and so, at the initiative of Lord Curzon, it was transferred from the Admiralty to the [[Foreign Office]].<ref>Smith, 2001, pp. 20–21</ref> GC&CS came under the supervision of Hugh Sinclair, who by 1923 was both the Chief of [[Secret Intelligence Service|SIS]] and Director of GC&CS.<ref name="johnson44"/> In 1925, both organisations were co-located on different floors of Broadway Buildings, opposite [[St. James's Park]].<ref name= "johnson44"/> Messages decrypted by GC&CS were distributed in blue-jacketed files that became known as "BJs".<ref>Smith, 2001, pp. 18–19</ref>

In the 1920s, GC&CS was successfully reading Soviet Union diplomatic ciphers. However, in May 1927, during a row over clandestine Soviet support for the [[1926 United Kingdom general strike|General Strike]] and the distribution of subversive propaganda, Prime Minister [[Stanley Baldwin]] made details from the decrypts public.<ref>Aldrich, 2010, p. 18</ref>

{{Main|Ultra (cryptography)}}

During the Second World War, GC&CS was based largely at [[Bletchley Park]] in present-day [[Milton Keynes]] working on, most famously, the German [[Enigma machine]] and [[Lorenz cipher]]s,<ref>{{cite book |first=Paul |last=Gannon |title=Colossus: Bletchley Park’s Greatest Secret |publisher=Atlantic Books |year=2006 |isbn=978-1-84354-331-2}}</ref> but also a large number of other systems. In 1940, GC&CS was working on the diplomatic codes and ciphers of 26 countries, tackling over 150 diplomatic cryptosystems.<ref>{{cite book |first=David |last=Alvarez |chapter=Most Helpful and Cooperative: GC&CS and the Development of American Diplomatic Cryptanalysis, 1941-1942 |title=Action This Day: Bletchley Park from the Breaking of the Enigma Code to the Birth of the Modern Computer |editor1-first=Michael |editor1-last=Smith |editor2-first=Ralph| editor2-last=Erskine |publisher=Bantam Press |year=2001 |isbn=978-0593049105}}</ref> Senior staff included [[Alastair Denniston]], [[Oliver Strachey]], [[Dilly Knox]], [[John Tiltman]], [[Edward Travis]], [[Ernst Fetterlein]], [[Josh Cooper (cryptographer)|Josh Cooper]], [[Donald Michie]], [[Alan Turing]], [[Max Newman]], [[William Tutte]], [[I. J. Good|I. J. (Jack) Good]], [[Peter Calvocoressi]] and [[Hugh Foss]].

An outstation in the Far East, the [[Far East Combined Bureau]] was set up in Hong Kong in 1935, and moved to Singapore in 1939. Subsequently with the Japanese advance down the Malay Peninsula, the Army and RAF codebreakers went to the [[Wireless Experimental Centre]] in Delhi, India. The Navy codebreakers in FECB went to [[Colombo]], Ceylon, then to [[Kilindini]], near [[Mombasa]], Kenya.

GC&CS was renamed the "Government Communications Headquarters" in June 1946.<ref>{{Cite book|last= Smith|first=Michael|title=Station X|year=1998|publisher=Channel 4 books|isbn=0-330-41929-3|page= 176}}</ref>

===Post Second World War===
GCHQ was at first based in [[RAF Eastcote|Eastcote]], but in 1951<ref>{{Cite web|url=http://www.gchq.gov.uk/about/moving5.html|title=History of GCHQ Cheltenham|work=GCHQ website 'About Us' pages|accessdate=29 June 2006 |archiveurl = http://web.archive.org/web/20061005175413/http://www.gchq.gov.uk/about/moving5.html <!-- Bot retrieved archive --> |archivedate = 5 October 2006}}</ref> moved to the outskirts of [[Cheltenham]], setting up two sites there – Oakley and Benhall. GCHQ had a very low profile in the media until 1983 when the trial of [[Geoffrey Prime]], a [[KGB]] mole within GCHQ, created considerable media interest.<ref>Aldrich, 2010, p. 382</ref>

Since the days of the Second World War, US and British intelligence have shared information. For the GCHQ this means that it shares information with, and gets information from, the [[National Security Agency]] (NSA) in the United States.<ref>{{cite book |title=Dirty Diplomacy |first=Craig |last=Murray |date=16 October 2007 |publisher=Scribner |page=332 |isbn=978-1416548010}}</ref>

====Public key encryption====
Early in the 1970s, the concept for public key encryption was developed and proven by [[James H. Ellis]], a GCHQ staff member since 1952, who lacked the necessary number theory expertise necessary to build a workable system.  Subsequently a feasible implementation scheme via an [[asymmetric key algorithm]] was invented by another staff member [[Clifford Cocks]], a mathematics graduate. This fact was kept secret until 1997.<ref>{{cite web |first=Simon |last=Singh |authorlink=Simon Singh |url=http://simonsingh.net/media/articles/maths-and-science/unsung-heroes-of-cryptography/ |title=Unsung Heroes of Cryptography |accessdate=}} (originally published in [[The Sunday Telegraph]])</ref>

====Trade union disputes====
[[File:NUCPS banner.jpg|thumb|left|[[NUCPS]] banner on march in [[Cheltenham]] 1992]]
{{main|Council of Civil Service Unions v Minister for the Civil Service}}
In 1984, GCHQ was the centre of a political row when the [[Conservative Party (UK)|Conservative]] government of [[Margaret Thatcher]] prohibited its employees from belonging to a trade union. It was claimed that joining a union would be in conflict with [[national security]]. A number of mass national one-day strikes were held to protest this decision, seen as a first step to wider bans on trade unions. Appeals to British Courts and [[European Commission of Human Rights]]<ref>{{cite web |url=http://cmiskp.echr.coe.int/tkp197/view.asp?action=html&documentId=664551&portal=hbkm&source=externalbydocnumber&table=F69A27FD8FB86142BF01C1166DEA398649 |title=EComHR Inadmissibility decision of EComHR on application no. 11603/85 |year=1987}}</ref> were unsuccessful. The government offered a sum of money to each employee who agreed to give up their union membership. Appeal to the [[ILO]] resulted in a decision that government's actions were in violation of [[ILO Convention 87|Freedom of Association and Protection of the Right to Organise Convention]].<ref>{{cite web |url=http://cmiskp.echr.coe.int/tkp197/view.asp?action=html&documentId=664551&portal=hbkm&source=externalbydocnumber&table=F69A27FD8FB86142BF01C1166DEA398649 |title=EComHR Inadmissibility decision of EComHR on application no. 11603/85 — The Facts}} para. IV</ref> The ban was eventually lifted by the incoming [[Labour Party (UK)|Labour]] government in 1997, with the Government Communications Group of the Public and Commercial Services (PCS) Union being formed to represent interested employees at all grades.<ref>{{Cite web|url=http://www.gchq.gov.uk/recruitment/union.html|title=Union representation|work=GCHQ website|accessdate=12 April 2006}}</ref> In 2000, a group of 14 former GCHQ employees, who had been dismissed after refusing to give up their union membership, were offered re-employment, which three of them accepted.<ref>{{Cite news|url= http://news.bbc.co.uk/1/hi/uk/627574.stm|title=Sacked GCHQ workers win compensation|publisher=BBC News|date=1 February 2000|accessdate=12 April 2006}}</ref>

===Post Cold War ===

====1990s: Post-Cold War restructuring====
The [[Intelligence Services Act 1994]] placed the activities of the intelligence agencies on a legal footing for the first time, defining their purpose, and the British Parliament's [[Intelligence and Security Committee]] was given a remit to examine the expenditure, administration and policy of the three intelligence agencies.<ref name='ISC'>{{cite web|title=ISC - About|url=http://isc.independent.gov.uk/|work=The Intelligence and Security Committee of Parliament - About the Committee|publisher=Intelligence and Security Committee of Parliament|accessdate=1 December 2013}}</ref> The objectives of GCHQ were defined as working as "in the interests of national security, with particular reference to the defence and foreign policies of Her Majesty's government; in the interests of the economic wellbeing of the United Kingdom; and in support of the prevention and the detection of serious crime".<ref name='InTel94'>{{cite web|title=Intelligence Services Act 1994|url=http://www.legislation.gov.uk/ukpga/1994/13/section/3|work=Intelligence Services Act 1994|publisher=The National Archives|accessdate=1 December 2013}}</ref> During the introduction of the Intelligence Agency Act in late 1993, the former Prime Minister [[Jim Callaghan]] had described GCHQ as a "full blown bureaucracy", adding that future bodies created to provide oversight of the intelligence agencies should "investigate whether all the functions that GCHQ carries out today are still necessary."<ref name="Dec93Hans">{{cite web|title=Hansard: December 1993 Intelligence Services Bill|work=Hansard|date=9 December 1993|url=http://hansard.millbanksystems.com/lords/1993/dec/09/intelligence-services-bill-hl}}</ref>

In 1993, in the wake of the "[[Squidgygate]]" affair, GCHQ denied "intercepting, recording or disclosing" the telephone calls of the British Royal family.<ref name="Aldrich, 2010, 483" >{{harvnb|Aldrich|2010|p=483}}</ref>

In late 1993 civil servant [[Michael Quinlan (civil servant)|Michael Quinlan]] advised a deep review of the work of GCHQ following the conclusion of his "Review of Intelligence Requirements and Resources", which had imposed a 3% cut on the agency.<ref name="Aldrich, 2010, 493" >{{harvnb|Aldrich|2010|p=493}}</ref> The [[Chief Secretary to the Treasury]], [[Jonathan Aitken]], subsequently held face to face discussions with the intelligence agency directors to assess further savings in the wake of Quinlan's review. Aldrich (2010) suggests that Sir [[John Adye]], the then Director of GCHQ performed badly in meetings with Aitken, leading Aitken to conclude that GCHQ was "suffering from out-of-date methods of management and out-of-date methods for assessing priorities".<ref name="Aldrich, 2010, 494" >{{harvnb|Aldrich|2010|p=494}}</ref>  GCHQ's budget was £850 million in 1993, (£{{Formatprice|{{Inflation|UK|850000000|1993|{{CURRENTYEAR}}|r=0}}}}) as of {{CURRENTYEAR}}){{Inflation-fn|UK}} compared to £125 million for MI5 and SIS. In December 1994 the businessman Roger Hurn was commissioned to begin a review of GCHQ, which was concluded in March 1995.<ref name="Aldrich, 2010, 495" >{{harvnb|Aldrich|2010|p=495}}</ref>  Hurn's report recommended a cut of £100 million in GCHQ's budget, such a large reduction had not been suffered by any British intelligence agency since the end of World War II.<ref name="Aldrich, 2010, 495"/> The J Division of GCHQ, which had collected SIGINT on Russia, disappeared as result of the cuts.<ref name="Aldrich, 2010, 495"/> The cuts had been mostly reversed by 2000 in the wake of threats from [[violent non-state actor]]s, and risks from increased terrorism, organised crime and illegal access to nuclear, chemical and biological weapons.<ref name="Aldrich, 2010, 505" >{{harvnb|Aldrich|2010|p=505}}</ref>

[[David Omand]] became the Director of GCHQ in 1996, and greatly restructured the agency in the face of new and changing targets and rapid technological change.<ref name="Aldrich, 2010, 496" >{{harvnb|Aldrich|2010|p=496}}</ref> Omand introduced the concept of "Sinews" (or "SIGINT New Systems") which allowed more flexible working methods, avoiding overlaps in work by creating fourteen domains, each with a well-defined working scope.<ref name="Aldrich, 2010, 496"/> The tenure of Omand also saw the planning and the creation of [[The Doughnut]], GCHQ's modern headquarters.<ref name="Aldrich, 2010, 496"/> Located on a 176-acre site in Benhall, near Cheltenham, The Doughnut would be the largest building constructed for secret intelligence operations outside the United States.<ref name="Aldrich, 2010, 9" >{{harvnb|Aldrich|2010|p=9}}</ref>

Operations at GCHQ’s Chum Hom Kwok listening station in Hong Kong ended in 1994.<ref name="Aldrich, 2010, 475" >{{harvnb|Aldrich|2010|p=475}}</ref> GCHQ's Hong Kong operations were extremely important to their relationship with the NSA, who contributed investment and equipment to the station. In anticipation of the [[Transfer of sovereignty over Hong Kong|transfer of Hong Kong to the Chinese government]] in 1997, the Hong Kong stations operations were moved to [[Geraldton]] in Australia.<ref name="West2012">{{cite book|author=Nigel West|title=Historical Dictionary of Signals Intelligence|url=http://books.google.com/books?id=maJbZGwK4BAC&pg=PR27|date=31 August 2012|publisher=Scarecrow Press|isbn=978-0-8108-7391-9|pages=27–}}</ref>

Operations that utilised GCHQ's intelligence-gathering capabilities in the 1990s included the monitoring of communications of Iraqi soldiers in the [[Gulf War]], of [[dissident republican]] terrorists and the [[Real IRA]], of the various factions involved in the [[Yugoslav Wars]], and of the criminal [[Kenneth Noye]].<ref name="Aldrich, 2010, 505"/><ref name="West2012"/><ref name="Aldrich, 2010, 473" >{{harvnb|Aldrich|2010|p=473}}</ref> In the mid 1990s GCHQ began to assist in the investigation of [[Computer crime|cybercrime]].<ref name="Aldrich, 2010, 489" >{{harvnb|Aldrich|2010|p=489}}</ref>

====2000s: Coping with the internet ====
{{See also|Global surveillance|Global surveillance disclosures (2013–present)}}
At the end of 2003, GCHQ moved to a new circular HQ (popularly known as "The Doughnut"): at the time, it was the second-largest public-sector building project in Europe, with an estimated cost of £337 million. The new building, which was designed by [[Gensler]] and constructed by [[Carillion]],<ref>{{cite news |url=http://news.bbc.co.uk/1/hi/business/931773.stm |title=Carillion set for growth |publisher=BBC News |date=19 September 2000 |accessdate=}}</ref> is the base for all of GCHQ's [[Cheltenham]] operations.

The public spotlight fell on GCHQ in late 2003 and early 2004 following the sacking of [[Katharine Gun]] after she leaked to ''[[The Observer]]'' a confidential email from agents at the United States' [[National Security Agency]] addressed to GCHQ agents about the wiretapping of UN delegates in the run-up to the [[2003 invasion of Iraq|2003 Iraq war]].<ref>Aldrich, 2010, p. 521</ref>

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. The listening stations are at Cheltenham itself, [[GCHQ Bude|Bude]], [[GCHQ Scarborough|Scarborough]], [[Ascension Island]], and with the United States at [[Menwith Hill]].<ref>{{cite journal |last=Campbell |first=Duncan |authorlink=Duncan Campbell (journalist) |title=Phone tappers and the state |magazine=New Statesman |year=1981 |page=54}}</ref> [[Ayios Nikolaos Station]] in Cyprus is run by the [[British Armed Forces]] for GCHQ.<ref>Aldrich, 2010, p. 471</ref>

In March 2010, GCHQ was criticised by the [[Intelligence and Security Committee]] for problems with its IT security practices and failing to meet its targets for work targeted against cyber attacks.<ref>{{Cite web|url= http://www.computerworlduk.com/management/government-law/public-sector/news/index.cfm?newsid=19344 |title=‘Cavalier’ GCHQ online spy centre loses 35 laptops|publisher=Computerworld UK|date= 12 March 2010 |accessdate=}}</ref>

As revealed by [[Edward Snowden]] in ''[[The Guardian]]'', GCHQ spied on foreign politicians visiting the [[2009 G-20 London Summit]] by eavesdropping phonecalls, emails and monitoring their computers, and in some cases even ongoing after the summit via [[keylogger]]s that had been installed during the summit.<ref>The Guardian: [http://www.guardian.co.uk/uk/2013/jun/16/gchq-intercepted-communications-g20-summits GCHQ intercepted foreign politicians' communications at G20 summits], 16 June 2013</ref> Some of the information gained has been passed on to British politicians.

According to Edward Snowden, GCHQ has two principal umbrella programs for collecting communications: 
* "[[Mastering the Internet]]" (MTI) for internet traffic, which is extracted from fiber-optic cables and can be searched by using the [[Tempora]] computer system.
* "[[Global Telecoms Exploitation]]" (GTE) for telephone traffic.<ref name=bump>{{cite web | url=http://www.theatlanticwire.com/national/2013/06/uk-tempora-program/66490/  |author=Philip Bump  |title=The UK Tempora Program Captures Vast Amounts of Data – and Shares with NSA |publisher=The Atlantic Wire |date=21 June 2013 |accessdate=23 June 2013}}</ref>

GCHQ also has had access to the US internet monitoring programme [[PRISM (surveillance program)|PRISM]] since at least June 2010.<ref>{{cite web|title=Statement on GCHQ’s Alleged Interception of Communications under the US PRISM Programme|url=https://b1cba9b3-a-5e6631fd-s-sites.googlegroups.com/a/independent.gov.uk/isc/files/20130717_ISC_statement_GCHQ.pdf|publisher=Intelligence and Security Committee of Parliament|accessdate=17 December 2013|date=17 July 2013}}</ref> PRISM is said to give the National Security Agency and FBI easy access to the systems of nine of the world's top internet companies, including Google, Facebook, Microsoft, Apple, Yahoo, and Skype.<ref>{{Cite web|url= http://www.bbc.co.uk/news/world-22860964 |title=Scale and significance of NSA snooping claims|publisher=BBC |date= 11 June 2013 |accessdate=}}</ref>

In February 2014, The Guardian, based on documents provided by Snowden, revealed that GCHQ had indiscriminately collected 1.8 million private Yahoo webcam images from users across the world.<ref>{{cite web|url=http://www.theguardian.com/world/2014/feb/27/gchq-nsa-webcam-images-internet-yahoo|title=Optic Nerve: millions of Yahoo webcam images intercepted by GCHQ|date=28 February 2014|accessdate=2 March 2014}}</ref>

Soon after becoming Director of GCHQ in 2014, [[Robert Hannigan]] wrote an article in the [[Financial Times]] on the topic of [[internet surveillance]], stating that "however much [large US technology companies] may dislike it, they have become the command and control networks of choice for terrorists and criminals" and that GCHQ and its sister agencies "cannot tackle these challenges at scale without greater support from the private sector", arguing that most internet users "would be comfortable with a better and more sustainable relationship between the [intelligence] agencies and the tech companies". Since the [[Global surveillance disclosures (2013–present)|2013 global surveillance disclosures]], large US technology companies have improved security and become less co-operative with foreign intelligence agencies, including those of the UK, generally requiring a US court order before disclosing data.<ref name=ft-20141103rh>{{cite news |url=http://www.ft.com/cms/s/2/c89b6c58-6342-11e4-8a63-00144feabdc0.html |title=The web is a terrorist's command-and-control network of choice |author=Robert Hannigan |newspaper=Financial Times |date=3 November 2014 |accessdate=3 November 2014}}</ref><ref name=ft-20141103>{{cite news |url=http://www.ft.com/cms/s/2/4a35c0b2-636e-11e4-9a79-00144feabdc0.html |title=Tech groups aid terror, says UK spy chief |author=Sam Jones and Murad Ahmed |newspaper=Financial Times |date=3 November 2014 |accessdate=3 November 2014}}</ref> However the head of the UK technology industry group [[techUK]] rejected these claims, stating that they understood the issues but that disclosure obligations "must be based upon a clear and transparent legal framework and effective oversight rather than, as suggested, a deal between the industry and government".<ref name=telegraph-20141104>{{cite news |url=http://www.telegraph.co.uk/technology/11208999/Tech-giants-reject-GCHQ-boss-Robert-Hannigans-call-for-deal-with-government.html |title=Tech giants reject GCHQ boss Robert Hannigan's call for deal with government |author=David Barrett |newspaper=Daily Telegraph |date=4 November 2014 |accessdate=5 November 2014}}</ref>

==CESG==
CESG (originally Communications-Electronics Security Group) is the group within GCHQ which provides assistance to government departments on their own communications security: 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]] and the Heilbronn Institute at the [[University of Bristol]].<ref>{{Cite web|url=http://www.maths.bristol.ac.uk/research/heilbronn_institute/|title=Heilbronn Institute for Mathematical Research |publisher=[[University of Bristol]] |accessdate=30 August 2008}}</ref>

CESG runs a number of schemes such as CHECK, [[CESG Listed Adviser Scheme|CLAS]], [[Commercial Product Assurance]], and [[CESG Claims Tested Mark]] and CAPS.<ref>{{cite web|url=http://www.cesg.gov.uk/products_services/iacs/index.shtml|accessdate=2 November 2010|title=Information Assurance & Consultancy Services (IACS)}}</ref>

==Joint Technical Language Service==
The Joint Technical Language Service (JTLS) was established in 1955,<ref>{{cite book |url=http://books.google.com/?id=8usCJVZY1vkC&pg=PA40&lpg=PA40&dq=%22Joint+Technical+Language+Service%22#v=onepage&q=%22Joint%20Technical%20Language%20Service%22&f=false |title=About Translation |first=Peter |last=Newmark |year=1991 |isbn=1-85359-118-1 |publisher=Multilingual Matters |page=40}}</ref> drawing on members of the small Ministry of Defence technical language team and others, initially to provide standard English translations for organisational expressions in any foreign language, discover the correct English equivalents of technical terms in foreign languages and discover the correct expansions of abbreviations in any language. The remit of the JTLS has expanded in the ensuing years to cover technical language support and interpreting and translation services across the UK Government and to local public sector services in [[Gloucestershire]] and surrounding counties. The JTLS also produces and publishes foreign language working aids under crown copyright and conducts research into machine translation and on-line dictionaries and glossaries.

The JTLS is co-located with GCHQ for administrative purposes.

==International relationships==
GCHQ operates in partnership with equivalent agencies worldwide in a number of bi-lateral and multi-lateral relationships. The principal of these is with the United States ([[National Security Agency]]), Canada ([[Communications Security Establishment]]), Australia ([[Australian Signals Directorate]]) and New Zealand ([[New Zealand Government Communications Security Bureau|Government Communications Security Bureau]]), through the mechanism of the [[UK-US Security Agreement]], a broad intelligence-sharing agreement encompassing a range of intelligence collection methods.

Relationships are alleged to include shared collection methods, such as the system described in the popular media as [[ECHELON]], as well as analysed product.<ref name=EP>{{Cite web|url=http://www.fas.org/irp/program/process/rapport_echelon_en.pdf|title=On the existence of a global system for the interception of private and commercial communications (ECHELON interception system) – Temporary Committee on the ECHELON Interception System, (2001/2098(INI))|last=Schmid|first=Gerhard|date=11 July 2001|format=pdf |pages=194 |publisher=European Parliament: Temporary Committee on the ECHELON Interception System| accessdate=27 March 2008}}</ref>

== Legal basis ==

{{Main|Intelligence Services Act 1994}}

GCHQ's legal basis is enshrined in the [[Intelligence Services Act 1994]] Section 3 as follows:

{{Blockquote|(1) There shall continue to be a Government Communications Headquarters under the authority of the Secretary of State; and, subject to subsection (2) below, its functions shall be—
:(a) to monitor or interfere with electromagnetic, acoustic and other emissions and any equipment producing such emissions and to obtain and provide information derived from or related to such emissions or equipment and from encrypted material; and
:(b) to provide advice and assistance about—
::(i) languages, including terminology used for technical matters, and
::(ii) cryptography and other matters relating to the protection of information and other material, to the armed forces of the Crown, to Her Majesty's Government in the United Kingdom or to a Northern Ireland Department or to any other organisation which is determined for the purposes of this section in such manner as may be specified by the Prime Minister. 
(2) The functions referred to in subsection (1)(a) above shall be exercisable only— 
:(a) in the interests of national security, with particular reference to the defence and foreign policies of Her Majesty's Government in the United Kingdom; or
:(b) in the interests of the economic well-being of the United Kingdom in relation to the actions or intentions of persons outside the British Islands; or 
:(c) in support of the prevention or detection of serious crime. 
(3) In this Act the expression "GCHQ" refers to the Government Communications Headquarters and to any unit or part of a unit of the armed forces of the Crown which is for the time being required by the Secretary of State to assist the Government Communications Headquarters in carrying out its functions.<ref>[http://www.legislation.gov.uk/ukpga/1994/13/section/3 Copy of section 3] of the [[Intelligence Services Act 1994]], from [[Legislation.gov.uk]]</ref>}}

Interception of communications operations are authorised under the [[Regulation of Investigatory Powers Act 2000]]. Warrants authorising such interception can only be issued by a [[Secretary of State (United Kingdom)|Secretary of State]]. The [[Human Rights Act 1998]] requires public bodies, like GCHQ, to protect citizens' rights under the [[European Convention on Human Rights]].<ref name=GCHQlaw>{{cite web|title=The Law|url=http://www.gchq.gov.uk/how_we_work/running_the_business/oversight/Pages/The-law.aspx|publisher=GCHQ|accessdate=17 December 2013}}</ref><ref name=refBBC20141205>{{cite news|title=GCHQ does not breach human rights, judges rule|url=http://www.bbc.co.uk/news/uk-30345801|accessdate=6 December 2014|publisher=BBC|date=5 December 2014}}</ref><ref>{{cite news|title=The Andrew Marr Show Interview: Theresa May, MP Home Secretary|url=http://news.bbc.co.uk/1/shared/bsp/hi/pdfs/2311201402.pdf|accessdate=6 December 2014|publisher=BBC|date=23 November 2014|quote=Well I guess what he’s talking about is the fact that for certain aspects and certain of the more intrusive measures that our security service and police have available to them – i.e. Intercept, intercepting people’s telephones and some other intrusive measures – the decision is taken by the Secretary of State, predominantly me. A significant part of my job is looking at these warrants and signing these warrants. I think it’s ... Some people argue that should be to judges....I think it’s very important that actually those decisions are being taken by somebody who is democratically accountable to the public. I think that’s an important part of our system. I think it’s a strength of our system.}}</ref>

=== Oversight ===

The [[Parliament of the United Kingdom]] appoints an [[Intelligence and Security Committee]]. The remit of the Committee includes oversight of intelligence and security activities and reports are made directly to Parliament.<ref>{{cite web|url=http://isc.independent.gov.uk/|title=The Intelligence and Security Committee of Parliament|accessdate=14 December 2013}}</ref> Its functions were increased under the [[Justice and Security Act 2013]] to provide for further access and investigatory powers.

Judicial oversight of GCHQ's conduct is exercised by the [[Investigatory Powers Tribunal]].<ref>{{cite web|title=Functions - Key role|url=http://www.ipt-uk.com/section.aspx?pageid=1|publisher=The Investigatory Powers Tribunal|accessdate=6 February 2015}}</ref> The UK also has an independent [[Intelligence Services Commissioner]] and Interception of Communications Commissioner, both of whom are former senior judges.<ref>{{cite web|url=http://www.intelligencecommissioners.com/|title=Intelligence Commissioners|accessdate=14 December 2013}}</ref>

The Investigatory Powers Tribunal ruled in December 2014 that GCHQ does not breach the [[European Convention of Human Rights]], and that its activities are compliant with Articles 8 (right to privacy) and 10 (freedom of expression) of the European Convention of Human Rights.<ref name=refBBC20141205 /> However, the Tribunal stated in February 2015 that one particular aspect, the data-sharing arrangement that allowed UK Intelligence services to request data from the US surveillance programmes [[PRISM (surveillance program)|Prism]] and [[Upstream collection|Upstream]], had been in contravention of human rights law prior to this until two paragraphs of additional information, providing details about the procedures and safeguards, were disclosed to the public in December 2014.<ref>{{cite web|title=IPT Ruling on Interception|url=http://www.gchq.gov.uk/press_and_media/news_and_features/Pages/IPT-Ruling-on-Interception-Feb-2014.aspx|publisher=GCHQ|accessdate=6 February 2015}}</ref><ref>{{cite news|title=GCHQ censured over sharing of internet surveillance data with US|url=http://www.bbc.com/news/uk-31164451|accessdate=6 February 2015|publisher=BBC|date=6 February 2015}}</ref><ref>{{cite news|title=UK-US surveillance regime was unlawful ‘for seven years’|url=http://www.theguardian.com/uk-news/2015/feb/06/gchq-mass-internet-surveillance-unlawful-court-nsa|accessdate=6 February 2015|publisher=The Guardian|date=6 February 2015}}</ref>

Furthermore, the IPT ruled that the legislative framework in the United Kingdom does not permit mass surveillance and that GCHQ does not practice mass surveillance.<ref name=refBBC20141205 /><ref>{{cite web|title=IPT rejects assertions of mass surveillance|url=http://www.gchq.gov.uk/press_and_media/news_and_features/Pages/IPT-rejects-assertions-of-mass-surveillance.aspx|publisher=GCHQ|accessdate=7 February 2015|date=5 December 2014}}</ref><ref>{{cite web|title=List of judgments|url=http://www.ipt-uk.com/section.aspx?pageid=8|publisher=Investigatory Powers Tribunal|accessdate=7 February 2015|date=5 December 2014|quote=1. A declaration that the regime governing the soliciting, receiving, storing and transmitting by UK authorities of private communications of individuals located in the UK which have been obtained by US authorities pursuant to Prism and/or Upstream does not contravene Articles 8 or 10 ECHR. 2. A declaration that the regime in respect of interception under ss8(4), 15 and 16 of the Regulation of investigatory Powers Act 2000 does not contravene Articles 8 or 10 ECHR and does not give rise to unlawful discrimination contrary to Article 14, read together with Articles 8 and/or 10 of the ECHR.}}</ref> This complements independent reports by the Interception of Communications Commissioner,<ref>{{cite web|title=Annual report 2013|url=https://www.gov.uk/government/publications/interception-of-communications-commissioner-annual-report-2013|publisher=Interception of Communications Commissioner|accessdate=7 February 2015}}</ref> and statements made by the [[Intelligence and Security Committee of Parliament]].<ref>{{cite web|url=https://b1cba9b3-a-5e6631fd-s-sites.googlegroups.com/a/independent.gov.uk/isc/files/20130717_ISC_statement_GCHQ.pdf?attachauth=ANoY7cqTsvkP1s9cldkJgvSkZY4Cl18vQQNCHXT0lytbZQY6zjDhG29JmnO_UdDhbBV1U7WGiXHQxmZH3Q1_QxNhA0Ek8_zoLaVfzQpAT4vy2ltXZPb6RRkU4LJjCAI7GcNhXXeT7bMstiiEdKgZtgx3QqNiNXVuNyYvFY4CmU8Gw5Fb5JMTlcWkAv31JYtnYf7qATGz-Ia1nEnzKf-iq3wtNHnnSqmBG98FC2XhFX2annOSP6eywzU%3D&attredirects=0|title=Statement on GCHQ’s Alleged Interception of Communications under the US PRISM Programme|publisher=House of Commons|date=17 July 2013|accessdate=7 February 2015}}</ref>

==Constitutional legal case==
A controversial GCHQ case determined the scope of judicial review of prerogative powers (the Crown's residual powers under common law). This was ''[[Council of Civil Service Unions v Minister for the Civil Service]]'' [1985] AC 374 (often known simply as the "GCHQ case"). In this case, a prerogative Order in Council had been used by the prime minister (who is the [[Minister for the Civil Service]]) 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 simply because it uses powers derived from common law rather than statute (thus the prerogative is reviewable). Controversially, they also held that although the failure to consult was unfair, this was overridden by concerns of national security.

==Leadership==
{{Main|Director of the Government Communications Headquarters}}
The following is a list of the heads of the operational heads of GCHQ and GC&CS:

*[[Alastair Denniston]] <small>[[Companion of the Order of St Michael and St George|CMG]] [[Commander of the Order of the British Empire|CBE]]</small> (1921 – February 1942) (continued as Deputy Director (Diplomatic and Commercial) until 1945).
*Sir [[Edward Travis]] <small>[[Knight Commander of the Order of St Michael and St George|KCMG]] CBE</small> (February 1942 – 1952)
*Sir [[Eric Malcolm Jones|Eric Jones]] <small>KCMG [[Companion of the Order of the Bath|CB]] [[Order of the British Empire|CBE]]</small> (April 1952 – 1960)
*Sir [[Clive Loehnis]] <small>KCMG</small> (1960–1964)
*Sir [[Leonard James Hooper|Leonard Hooper]] <small>KCMG CBE</small> (1965–1973)
*Sir [[Arthur Bonsall]] <small>KCMG CBE </small> (1973–1978)
*Sir [[Brian Tovey|Brian John Maynard Tovey]] <small>KCMG</small> (1978–1983)
*Sir [[Peter Marychurch]] <small>KCMG</small> (1983–1989)
*Sir [[John Adye|John Anthony Adye]] <small>KCMG</small> (1989–1996)
*Sir [[David Omand]] <small>[[Knight Grand Cross of the Order of the Bath|GCB]]</small> (1996 –1997)
*Sir [[Kevin Tebbit]] <small>[[Knight Commander of the Order of the Bath|KCB]] CMG</small> (1998)
*Sir [[Francis Richards (diplomat)|Francis Richards]] <small>KCMG [[Commander of the Royal Victorian Order|CVO]] [[Deputy Lieutenant|DL]]</small> (1998–2003)
*Sir [[David Pepper]] <small>KCMG</small> (2003–2008)
*Sir [[Iain Lobban]] <small>KCMG CB</small> (2008–2014)
*[[Robert Hannigan]] <small>CMG</small> (2014–present)

==Stations and former stations==
The following are the stations and former stations that continued to operate through the [[Cold War]]:<ref>{{cite web|url=https://books.google.co.uk/books?id=2jCbW82ABTkC&pg=PA8&lpg=PA8&dq=GCHQ+Stations&source=bl&ots=BiIkh-v7rC&sig=TKuq603T4gLUgQMs9lKtInvi7_Q&hl=en&sa=X&ei=rnCLVIrsFo_laMmbgrgD&ved=0CFMQ6AEwCDgK#v=onepage&q=GCHQ%20Stations&f=false|title=How Cheltenham entered America's backyard|publisher=New Scientist|date=5 April 1984|accessdate=12 December 2014}}</ref>
* Current stations
** [[Ascension Island|GCHQ Ascension Island]]
** [[GCHQ Bude]]
** [[GCHQ Scarborough]]
* Former stations
** [[Brora Y Station|GCHQ Brora]]
** [[Woodhead Hall|GCHQ Cheadle]]
** [[RAF Culmhead|GCHQ Culmhead]]
** [[Hawklaw Y Station|GCHQ Hawklaw]]
** [[RAF Little Sai Wan|GCHQ Hong Kong]]

==In popular culture==
The historical drama ''[[The Imitation Game]]'' featured [[Benedict Cumberbatch]] portraying [[Alan Turing]]'s efforts to break the Enigma code as part of the Government Code and Cypher School, the forerunner of GCHQ.<ref>{{cite news|title=Benedict Cumberbatch to inspire the next generation of codebreakers|url=http://www.theguardian.com/film/2014/nov/15/benedict-cumberbatch-imitation-game-bletchley-park|accessdate=6 December 2014|publisher=The Observer|date=15 November 2014}}</ref>

==See also==
{{Portal|United Kingdom|Mass surveillance|Intelligence}}
* [[Capenhurst]]
* [[Conel Hugh O'Donel Alexander|Hugh Alexander]] – head of the cryptanalysis division at GCHQ from 1949–1971
* [[Joint Threat Research Intelligence Group]]
* [[Mass surveillance in the United Kingdom]]
* [[RAF Digby]]
* [[RAF Intelligence]]
* [[UK Cyber Security Community]]
* [[UKUSA Agreement]]
* [[Zircon (satellite)|Zircon]], the cancelled GCHQ satellite project
* [[Operation Socialist]]

==Notes and references==
{{Reflist|30em}}

==Bibliography==
* {{cite book |first=Richard J. |last=Aldrich |title=GCHQ: The Uncensored Story of Britain's Most Secret Intelligence Agency |publisher=HarperCollins |year=2010 |isbn=978-0007278473}}
*{{cite book |first=John |last=Johnson |title=The Evolution of British Sigint: 1653–1939 |year=1997 |publisher=HMSO |asin=B002ALSXTC}}
*{{cite book |first=David |last=Kahn |title=Seizing the Enigma: The Race to Break the German U-Boats Codes, 1939–1943 |publisher=Houghton Mifflin |year=1991 |isbn=978-0395427392}}
*{{cite book |first=Michael |last=Smith |chapter=GC&CS and the First Cold War |title=Action This Day: Bletchley Park from the Breaking of the Enigma Code to the Birth of the Modern Computer |editor1-first=Michael |editor1-last=Smith |editor2-first=Ralph| editor2-last=Erskine |publisher=Bantam Press |year=2001 |isbn=978-0593049105}}

==External links==
{{Commons category|Government Communications Headquarters}}
* {{Official website|1=http://www.gchq.gov.uk}}
* [http://www.hmgcc.gov.uk Her Majesty's Government Communications Centre]
* [http://www.cesg.gov.uk CESG]
* [http://www.govcertuk.gov.uk GovCertUK]
* [http://www2.warwick.ac.uk/fac/soc/pais/staff/aldrich/vigilant/lectures/gchq GCHQ: Britain's Most Secret Intelligence Agency]
* [http://www.bbc.co.uk/news/uk-england-gloucestershire-16290383 BBC: A final look at GCHQ's top secret Oakley site in Cheltenham]
* [http://electrospaces.blogspot.com/2014/11/incenser-or-how-nsa-and-gchq-are.html INCENSER, or how NSA and GCHQ are tapping internet cables]

{{Signals intelligence agencies}}
{{UK Intelligence Agencies}}
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{{Use dmy dates|date=April 2012}}

[[Category:Government Communications Headquarters|*]]
[[Category:1919 establishments in the United Kingdom]]
[[Category:British intelligence agencies]]
[[Category:Computer security organizations]]
[[Category:Cryptography organizations]]
[[Category:Foreign relations of the United Kingdom]]
[[Category:Government agencies established in 1919]]
[[Category:Organisations based in Cheltenham]]
[[Category:Signals intelligence agencies]]