Answer
Bletchley Park was the birthplace of the communications revolution, the cradle of the knowledge age. It was a community that changed the future, near London and mid-way between Oxford and Cambridge, UK, it was the secret centre for Allied codebreaking and intelligence during the Second World War. The codebreakers began to arrive in the summer of 1939.
Their mission: to crack the Nazi Enigma cypher.
The odds against them were a staggering 150,000,000,000,000,000,000 to 1.
Their success in breaking this seemingly ‘unbreakable’ code was one of the greatest intellectual achievements of the twentieth century, providing the Allied forces with a wealth of information about the enemy’s plans.
The world’s first computer, Colossus 1, was one of the technologies developed at Bletchley Park to speed up the process of analysis.
Post office engineers built Colossus for the code-breakers at Bletchley Park in 1943. The computer was as big as a room – 5 metres long, 3 metres deep and 2.5 metres high – and was made mainly from parts used for post office telephone and telegraph systems.
It was a development from the mechanical Bombes. Bombes were huge, noisy electro-mechanical machines, which could check through combinations of letters far quicker than a human being could. Sometimes messages began with the same words, such as a weather report. This gave clues (called a CRIB) about how the rest of the message had been encoded.
When the code-breakers eventually worked out what the CRIB letters might be, they tested them on the BOMBE. When the Bombe stopped, this meant that the code-breakers’ guesses were right. All that days U-boat messages could then be decoded.
Colossus worked by ‘reading’, through a photoelectric system, a teleprinter tape containing the letters of the coded message. It read 5,000 letters a second.
All possible combinations of the coded message were checked with the cypher key generated by Colossus. A teleprinter typed out the results of Colossus’s search, revealing the settings that had been used by the Germans to send their messages.
For many years it was believed that the American ENIAK was the first electronic digital calculator, this was due to the fact that Colossus was kept secret until the 1970s.
Bletchley Park’s contribution probably shortened WW2 by two years.
Keywords:bletchley park, enigma, world war 2, colossus, bombe