The Big Brother on Menwith Hill
It started with Enigma
Germany had developed the first prototypes of Enigma encrypting machines since the end of the World War I. Initially meant for civilian purposes, they started to be developed for military applications since around 1925. To break German codes, a large team was put together of British cryptanalysts, mathematicians, crossword and chess enthusiasts and various others and assigned to the manor of Bletchley Park near London.
At the height of its days, it consisted of as much as about 10 000 people. According to the Daily Telegraph, in one instance, the ability to solve The Daily Telegraph crossword in under 12 minutes was used as a recruitment test. The newspaper was asked to organise a crossword competition, after which each of the successful participants was contacted and asked if they would be prepared to undertake "a particular type of work as a contribution to the war effort".
The team, led by the famous mathematician Alan Turing, succeeded in breaking the Enigma codes in 1943 (using a number of electromechanical devices - the best known of which is probably the Colossus - which were arguably among the first modern computers). The effort called ULTRA had a substantial influence on the war - it has been suggested that without breaking the German codes, the war in Europe had lasted for two more years.
Actually, while the effort of British cryptanalysts in Bletchley Park is well known, the work in Poland before the war is much less recognized. By 1939, the Poles led by mathematician Marian Rejewski were able to read most of the encrypted texts - sharing the information with Brits in 1939 (and 3 key persons escaping to the French resistance movement) played a large part in overall success. And the final key was salvaging the code books from German submarine U559 which was discovered and forced to surface in Eastern Mediterranean Sea.
At the end of the war, much of the equipment used and its blueprints were destroyed. Although thousands of people were involved in the decoding efforts, the participants remained silent for decades about what they had done during the war, and it was only in the 1970s that the work at Bletchley Park was revealed to the general public. The manor was opened to the public as a museum in 1993.
The Quadripartite Agreement of 1947
In 1947, four English-speaking countries - the United States, the United Kingdom, Australia (together with New Zealand) and Canada - signed a secret treaty (some sources suggest that even Prime Ministers were kept unaware) about sharing intelligence data. The treaty has also been known as UKUSA (UK plus USA). As such, it was beneficial for the smaller (in terms of intelligence resources) partners who did not have comparable intelligence systems with the UK and the US. The treaty allowed sharing of raw intelligence data, but analysis and conclusions were made separately by each state, which sometimes led to contradictory results based on the same data. Under the terms of the agreement, the five nations carved up the earth into five spheres of influence, and each country was assigned particular signals intelligence targets (e.g. Britain was responsible for intercepting the Chinese, through its Hong Kong listening post, while the US was given other responsibilities to cover from its listening posts in Taiwan, Japan and Korea).
While the details of the treaty remain largely unknown to the public, it has been suggested that the infamous bypass system for the gentlemanly ban on domestic spying (a state would not spy after its own subjects at home) was born already with this treaty. A former employee of Canadian CSE (Communication Security Establishment) Mike Frost wrote a book titled Spyworld in 1994 which also has an account of Canadian agents snooping after Brits (see a review of the book by Bob Leonard.
The ECHELON Project