Cracking the Code: Six of the Most Important Code Advances of the 20th Century
Cracking the Code: Six of the Most Important Code Advances of the 20th Century

Cracking the Code: Six of the Most Important Code Advances of the 20th Century

Michelle Powell-Smith - January 10, 2017

Cracking the Code: Six of the Most Important Code Advances of the 20th Century

Bletchley Park

Bletchley Park was the central site of the British government codebreakers in World War II. Run by the Government Code and Cipher School, Bletchley Park remained a government secret until relatively recently. Decoded materials from Bletchley Park are commonly identified as “Ultra”. Tr

Near the end of August 1938, there was, in terms of appearances, a small gathering of friends at a mansion in the Buckinghamshire countryside. The individuals gathered at Bletchley Park in 1938 were not ordinary people enjoying a late summer break, but members of the British MI6 intelligence service and the Government Code and Cipher School, seeking an ideal location for a classified center for code breaking. A year later, work on Axis codes began in earnest at Bletchley Park. Large, pre-fabricated wooden huts supplemented the mansion and buildings already on the property.

While the Polish Cipher Bureau had broken Enigma, it had done so when the Germans were only changing the code once every few months. With the beginning of World War II, the Germans changed the Enigma settings daily. There were more than 159 million million million possibilities each day in the Enigma code.

Academics of all sorts, including mathematicians and chess champions were recruited for Bletchley Park; at one point, a crossword competition was held. Mathematicians were especially critical to decode Enigma.

On January 23, 1940, the team working under Dilly Knox, including Alan Turing, cracked a German army administrative key, codenamed “The green”. They moved on to crack other German codes, including codes used for air support. The Axis Lorenz cipher was also broken by the staff at Bletchley Park.

The knowledge gained by cracking these codes was highly confidential, and was used for the remainder of the war with the greatest of care. Historians believe that the work done at Bletchley Park likely shortened the war by two to four years and played a key role in securing the Allied victory over the Axis powers.

The centralization of Bletchley Park provided key organizational advantages. Codebreakers could decrypt codes and pass them directly to intelligence staff in neighboring huts.

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