I went to Bletchley Park last week for a fascinating day trip. Bletchley Park was the location where the British code breakers were based during World War II. It was from here that Alan Turing and many other incredibly gifted mathematicians, statisticians, and translators worked tirelessly throughout the war to continuously crack and decrypt the messages sent by the Germans.
During the war the Germans used several variants of an electro-mechanical rotatory cipher machine known as the Enigma machine. The Germans believed the encryption generated by these machine to be unbreakable. Theoretically there were in the order of 1.07 x 10²³ possible combinations for the Wehrmacht (Army) version of the machine. Fortunately (for the Allied forces) a weakness in the encryption method could be exploited and using a clever technique, alongside a custom build electro-mechanical device known as the Bombe, the message could be decrypted.
To learn a bit more about how the Enigma machine worked I decided to make an Enigma Machine Emulator in C.
When I have more time I will update this page with lots more information about how the Enigma Machine works.