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This inconspicous building housed some of the greatest minds of the 20th century.

Bletchley Park
Milton Keynes, UK

developer Captain Hubert Faulkner to sell the land, the GC&CS moved here from London in 1938, finding it a safer place for its work.

Photo courtesy of Flickr user Draco2008

The school’s main activity was breaking the Enigma ciphers. The Enigma cipher was the backbone of German military and intelligence communications and it was thought to be unbreakable since the probability to break the code without knowing its settings was about 150 million million million to one. The first break into Enigma came in 1940 after the school’s members took advantage of a fundamental design flaw and errors in messages sent by lazy German operators. Polish mathematicians had also broken Enigma during trials in 1932, providing priceless information toward the final break.

After World War II GC&CS operations stopped. Moreover, since the Cold War was approaching, Winston Churchill ordered the destruction of all evidence that could help the USSR in the war. Ex-employees departed, some of them continuing to break ciphers working under a new name, the Government Communications Headquarters. Bletchley Park hosted a number of training schools and kept its code-breaking activities secret until the mid-1970s when wartime information was declassified. Today it is home to the National Museum of Computing of the United Kingdom.

Perhaps some of the first code- breaking activities happened inside the walls of Bletchley Park during the World War II.
The United Kingdom’s main decryp-
tion establishment, known as the
Government Code and Cypher School
(GC&CS), significantly assisted the
Allied war effort. GC&CS produced
wartime signals intelligence under
the code-name “Ultra,” obtained by
breaking encrypted enemy radio and
teleprinter communications. Many of
the ciphers and codes generated by the
Enigma and Lorenz machines were
decrypted at Bletchley Park just 50
miles northwest of London, revealing
dangerous secrets of the Axis coun-
tries during the war.

HISTORY

In the 1880s Bletchley Park was originally the home of the Leon family, a wealthy financier family from London. After the death of its owners and an unsuccessful attempt by property

TURING AND THE PARK During the Second World War, Turing was one of the famous mathematicians and cryptanalysts who worked at Britain’s code-breaking center in Bletchley Park. As a member of the GC&CS he served as the head of Hut 8, the section responsible for German naval cryptanalysis. Turing managed to develop a number of techniques for breaking German ciphers, including the method of the Bombe, an electro-