Yesterday me and Mr S went to visit Bletchley Park in Buckinghamshire. Bletchley was purchased in 1938 for the government, by Admiral Sir Hugh Sinclair for £6,500. He paid, out of his own pocket by writing a cheque for the full amount. As far as we know Sinclair was never reimbursed for this expense and the estate is now the property of the Government, and maintained as a museum by the Bletchley Park Trust. It was purchased before the beginning of the Second world war, when the search begun for a home for the Government Code and Cipher school. No one except the Prime minister Neville Chamberlain, believed Hitler would keep his word and we would see ‘Peace in our time’. So the hunt was on for a property about 50 miles outside of London to house the code breaking teams as they believed, quite rightly that London would be bombed when war broke out. Bletchley, as you all know was the home of the crack code breaking team who broke the codes on the German Enigma, and Lorenz cipher machines saving thousands of lives and shortening the war by at least two years. The best and the brightest mathematicians, scientists and university undergraduates were called to Bletchley during the war, including Alan Turing who is the father of modern computing and Artificial intelligence and George Welchman who worked with Turing to design the Bombe, a technological wonder of the day.
The bombe (named after the favourite ice cream of the three Polish cryptologists who originally designed the machine to decipher German code) computed the correct Enigma machine setting for that day. The Enigma machine’s weakness is that no letter can be coded as itself, and that the German codes often started with the same call signals. Using this they could create a menu of the letters that matched up by pairing the gobbledygook coded message against the known call signals at the start of German coded messages. Since each letter could not be coded as itself it mean they could create a crib – a very educated guess if you like – of paired letters. It was these letters that were paired via the wiring on the back of the Bombe machine so the crib could be tested to see if the crib was correct. This did result in false stops, but once the bombe had a positive stop, it could be decrypted, translated and the intelligence used to our defence and aid our defeat of fascism. The dedication and sacrifice of the almost 10,000 people who worked at Bletchley during the war, assured our freedom now.
It wasn’t until 1975, that the residents of the village of Bletchley found out what important work had been carried out at Bletchley Park. To paraphrase Churchill it was ‘a riddle wrapped in a mystery inside an enigma’, everyone knew that it was important war work and knew not to ask. I guess the posters of ‘keep mum’, and this ‘tittle tattle’ poster worked