[ History of GCHQ ]
Today’s GCHQ is the product of over a century of organic
development. Modern Signals Intelligence (SIGNIT) began in two small
organisations at the start of the First World War and has evolved into an
integrated intelligence and security organisation with a responsibility for
defending UK interests worldwide.
Beginnings
What is now often referred to as “lawful interception” has been a feature of British life for centuries. As early as 1324, Edward II issued a writ demanding that couriers entering the kingdom carrying letters be imprisoned and their letters forwarded to the King. Queen Elizabeth I’s Secretary, Sir Francis Walsingham employed a cryptanalyst, Thomas Phellipes, who was responsible for decrypting intercepted messages. It was his decryption of messages sent by Mary, Queen of Scots, which led to her execution.
Cromwell established the first effective postal monopoly in the UK, and after the Restoration a further Act of Parliament confirmed the monopoly and authorised the opening of selected items of mail under warrant "to discover and prevent many dangerous and wicked Designs . . . the Intelligence whereof cannot well be Communicated but by Letter”.
This practice continued until 1844, when a scandal over the forwarding to the Austrian Ambassador of the contents of the intercepted letters of an Italian exile in London caused the existing “Secret Offices” to be closed down. As Britain's unchallenged naval superiority and its growing material prosperity grew, Victorian statesmen became able to dispense with the need for intercepted information for intelligence purposes, though the military, both in the UK and in India, began to glimpse the possibilities offered by interception and decryption from the time of the Boer War onwards.
Beginnings
What is now often referred to as “lawful interception” has been a feature of British life for centuries. As early as 1324, Edward II issued a writ demanding that couriers entering the kingdom carrying letters be imprisoned and their letters forwarded to the King. Queen Elizabeth I’s Secretary, Sir Francis Walsingham employed a cryptanalyst, Thomas Phellipes, who was responsible for decrypting intercepted messages. It was his decryption of messages sent by Mary, Queen of Scots, which led to her execution.
Cromwell established the first effective postal monopoly in the UK, and after the Restoration a further Act of Parliament confirmed the monopoly and authorised the opening of selected items of mail under warrant "to discover and prevent many dangerous and wicked Designs . . . the Intelligence whereof cannot well be Communicated but by Letter”.
This practice continued until 1844, when a scandal over the forwarding to the Austrian Ambassador of the contents of the intercepted letters of an Italian exile in London caused the existing “Secret Offices” to be closed down. As Britain's unchallenged naval superiority and its growing material prosperity grew, Victorian statesmen became able to dispense with the need for intercepted information for intelligence purposes, though the military, both in the UK and in India, began to glimpse the possibilities offered by interception and decryption from the time of the Boer War onwards.
The First World War
Starting almost from scratch, Britain built up a considerable Signals Intelligence effort during World War I. Alastair Denniston, who was to become the post-war Director of the organisation, later wrote that in 1914 "Cryptographers did not exist as far as we knew".
A number of radio intercept stations were created, and an increasing number of cryptanalysts, linguists and radio traffic analysts enjoyed considerable success not only in decrypting messages sent by Germany and its allies, but in disseminating the intelligence produced in a timely to where it was. needed, and integrating it with other sources of information.
The most famous Sigint report of WWI came from the decryption of a telegram sent by the German Foreign Minister, Count Zimmermann, in early 1917. It stated that as Germany was to undertake unrestricted submarine warfare against vessels (including neutral American ones) trading with the British, which might bring the USA into the War on the British side, Mexico would be rewarded with the recovery of its territories of Arizona, New Mexico and Texas if it joined the conflict. Release of the Zimmerman Telegram to the US authorities was one of the deciding factors in the USA joining the War on the side of the Allies.
Starting almost from scratch, Britain built up a considerable Signals Intelligence effort during World War I. Alastair Denniston, who was to become the post-war Director of the organisation, later wrote that in 1914 "Cryptographers did not exist as far as we knew".
A number of radio intercept stations were created, and an increasing number of cryptanalysts, linguists and radio traffic analysts enjoyed considerable success not only in decrypting messages sent by Germany and its allies, but in disseminating the intelligence produced in a timely to where it was. needed, and integrating it with other sources of information.
The most famous Sigint report of WWI came from the decryption of a telegram sent by the German Foreign Minister, Count Zimmermann, in early 1917. It stated that as Germany was to undertake unrestricted submarine warfare against vessels (including neutral American ones) trading with the British, which might bring the USA into the War on the British side, Mexico would be rewarded with the recovery of its territories of Arizona, New Mexico and Texas if it joined the conflict. Release of the Zimmerman Telegram to the US authorities was one of the deciding factors in the USA joining the War on the side of the Allies.
Inter-War
Sigint’s success in WWI and the interest of politicians such as Lloyd George, Lord Curzon, and Winston Churchill in Sigint reporting, led to the creation of a peacetime organisation in the Admiralty called the Government Code and Cypher School (GC&CS). It was initially a small organisation of 30 cryptanalysts and a similar number of support staff. Its job was “Construction, Destruction and Instruction”: providing advice on the security of British governmental codes and ciphers; the study of the methods of encryption used by foreign powers; and the training of British officials in the use of secure communications.
In 1922, the School was transferred from Admiralty control to the Foreign Office. It came under the administrative control of ‘C’, the Chief of the Secret Intelligence Service (SIS), though it remained completely autonomous of SIS in terms of what it collected and reported, and how it developed its capabilities. Naval, Military and Air Sections were added in the following years, and, after the Italian invasion of Abyssinia in 1935 and the start of the Spanish Civil War in 1936, GC&CS began to expand as the slide towards war began, and developed closer cooperation with naval and military collection sites worldwide, and, from 1938 onwards, with the Dominions.
Sigint’s success in WWI and the interest of politicians such as Lloyd George, Lord Curzon, and Winston Churchill in Sigint reporting, led to the creation of a peacetime organisation in the Admiralty called the Government Code and Cypher School (GC&CS). It was initially a small organisation of 30 cryptanalysts and a similar number of support staff. Its job was “Construction, Destruction and Instruction”: providing advice on the security of British governmental codes and ciphers; the study of the methods of encryption used by foreign powers; and the training of British officials in the use of secure communications.
In 1922, the School was transferred from Admiralty control to the Foreign Office. It came under the administrative control of ‘C’, the Chief of the Secret Intelligence Service (SIS), though it remained completely autonomous of SIS in terms of what it collected and reported, and how it developed its capabilities. Naval, Military and Air Sections were added in the following years, and, after the Italian invasion of Abyssinia in 1935 and the start of the Spanish Civil War in 1936, GC&CS began to expand as the slide towards war began, and developed closer cooperation with naval and military collection sites worldwide, and, from 1938 onwards, with the Dominions.
Second World War - Bletchley Park
Bletchley Park, a country house in Buckinghamshire, was bought by SIS in 1938 as a site to which GC&CS and SIS could be evacuated when war came: it was widely expected that London would be the target of a massive aerial assault at the very start of any war. During the Munich Crisis in the autumn of 1938 the Service sections were moved to BP. They returned to London after the crisis had passed, but BP was fitted out over the next few months with communications and power and the first wooden huts were erected in its grounds to cope with the size of the ever expanding GC&CS.
On 15 August 1939 about 180 GC&CS people moved from London to BP while about 20, who produced Communications Security materials (cipher keys, code books, one time pads etc.), moved to Mansfield College Oxford to be nearer their main printers, the Oxford University Press. By the end of 1944, some 10,000 people were employed at BP itself, with a larger number engaged on Sigint collection and dissemination tasks around the world.
BP’s great success was due to the mechanisation of the decryption process keeping pace with the mechanisation of encryption. Although the decryption of Enigma is the best known of BP’s exploits, other successes, such as the decryption of Luftwaffe hand ciphers, and the development of COLOSSUS, the world’s first computer, to solve enciphered German telecipher, made a significant contribution to allied victory.
In parallel with the growth of decryption, WWII saw the development of a handling system for Sigint reports which was designed to protect the source of the intelligence and restrict knowledge of it. This meant that the reporting could continue to provide uniquely valuable intelligence to allied commanders throughout the war.
Bletchley Park, a country house in Buckinghamshire, was bought by SIS in 1938 as a site to which GC&CS and SIS could be evacuated when war came: it was widely expected that London would be the target of a massive aerial assault at the very start of any war. During the Munich Crisis in the autumn of 1938 the Service sections were moved to BP. They returned to London after the crisis had passed, but BP was fitted out over the next few months with communications and power and the first wooden huts were erected in its grounds to cope with the size of the ever expanding GC&CS.
On 15 August 1939 about 180 GC&CS people moved from London to BP while about 20, who produced Communications Security materials (cipher keys, code books, one time pads etc.), moved to Mansfield College Oxford to be nearer their main printers, the Oxford University Press. By the end of 1944, some 10,000 people were employed at BP itself, with a larger number engaged on Sigint collection and dissemination tasks around the world.
BP’s great success was due to the mechanisation of the decryption process keeping pace with the mechanisation of encryption. Although the decryption of Enigma is the best known of BP’s exploits, other successes, such as the decryption of Luftwaffe hand ciphers, and the development of COLOSSUS, the world’s first computer, to solve enciphered German telecipher, made a significant contribution to allied victory.
In parallel with the growth of decryption, WWII saw the development of a handling system for Sigint reports which was designed to protect the source of the intelligence and restrict knowledge of it. This meant that the reporting could continue to provide uniquely valuable intelligence to allied commanders throughout the war.
Post-War
After the war GC&CS changed its name officially to Government Communications Headquarters (GCHQ) and moved its Headquarters to Eastcote in Middlesex (1946) and later to Cheltenham (1950s). But the Central Training School stayed at Bletchley Park until 1987, when it moved to Culmhead (near Taunton in Somerset).
From VJ day 1945 until the collapse of the Warsaw Pact in 1991 the dominant military threat to the United Kingdom was the military forces of the Soviet Bloc. These were therefore, unsurprisingly, the main focus of GCHQ's Sigint efforts; while adequate defence against the perceived current and likely future Sigint capabilities of the USSR was the standard to which CESG –designed Comsec devices, designs and doctrine aspired.
Starting in November 2007 GCHQ has been releasing to The National Archives at Kew copies of its intelligence reports on Soviet Bloc military and paramilitary activities up to 1950 and there are plans to begin release later reports as well. Since 1946 GCHQ has always provided intelligence and Information Assurance support to military, diplomatic and law enforcement Departments of the UK Government and its Allies. (Information Assurance subsumes traditional Comsec and, more recently, Computer Security and secure data handling advice and products.)
One of the enduring legacies of WWII is the Sigint relationship between the UK and the US, to which the Sigint agencies of Canada, Australia and New Zealand have also signed up. Details of the UKUSA Agreement and its development were released to the National Archives in 2009.
With the launch of Communications Satellites starting in the 1960s many communications disappeared from the traditional media of High Frequency (Short Wave) Morse and teleprinter; although neither has disappeared altogether, nor seems likely to. These changes enabled a dramatic reduction, from the 1970s, in the numbers of intercept stations owned or directed by GCHQ, required the opening of some new ones, and result in the much changed appearance and technology of those that remain.
GCHQ made a major breakthrough in the field of secure communications in 1973 when it developed what is now known as public-key encryption and in 1983, GCHQ gained a national profile when its function was avowed to Parliament. In 1984, GCHQ was thrust into the public eye when trade union rights were removed from its staff. In May 1999, the Foreign Secretary announced that he had chosen the site of GCHQ's new accommodation. The two existing sites made way for a single site at Benhall by means of a major new construction project of a design which is well suited to support GCHQ in meeting the challenges the future will bring.
After the war GC&CS changed its name officially to Government Communications Headquarters (GCHQ) and moved its Headquarters to Eastcote in Middlesex (1946) and later to Cheltenham (1950s). But the Central Training School stayed at Bletchley Park until 1987, when it moved to Culmhead (near Taunton in Somerset).
From VJ day 1945 until the collapse of the Warsaw Pact in 1991 the dominant military threat to the United Kingdom was the military forces of the Soviet Bloc. These were therefore, unsurprisingly, the main focus of GCHQ's Sigint efforts; while adequate defence against the perceived current and likely future Sigint capabilities of the USSR was the standard to which CESG –designed Comsec devices, designs and doctrine aspired.
Starting in November 2007 GCHQ has been releasing to The National Archives at Kew copies of its intelligence reports on Soviet Bloc military and paramilitary activities up to 1950 and there are plans to begin release later reports as well. Since 1946 GCHQ has always provided intelligence and Information Assurance support to military, diplomatic and law enforcement Departments of the UK Government and its Allies. (Information Assurance subsumes traditional Comsec and, more recently, Computer Security and secure data handling advice and products.)
One of the enduring legacies of WWII is the Sigint relationship between the UK and the US, to which the Sigint agencies of Canada, Australia and New Zealand have also signed up. Details of the UKUSA Agreement and its development were released to the National Archives in 2009.
With the launch of Communications Satellites starting in the 1960s many communications disappeared from the traditional media of High Frequency (Short Wave) Morse and teleprinter; although neither has disappeared altogether, nor seems likely to. These changes enabled a dramatic reduction, from the 1970s, in the numbers of intercept stations owned or directed by GCHQ, required the opening of some new ones, and result in the much changed appearance and technology of those that remain.
GCHQ made a major breakthrough in the field of secure communications in 1973 when it developed what is now known as public-key encryption and in 1983, GCHQ gained a national profile when its function was avowed to Parliament. In 1984, GCHQ was thrust into the public eye when trade union rights were removed from its staff. In May 1999, the Foreign Secretary announced that he had chosen the site of GCHQ's new accommodation. The two existing sites made way for a single site at Benhall by means of a major new construction project of a design which is well suited to support GCHQ in meeting the challenges the future will bring.
All information taken from GCHQ.gov.uk. No copyright infringement intended.