When I read an account of how the enigma decoder turned up in the hands of the English I was very suprised. The story doesn't seem to come to light often. Here is how it was presented in the Time-Life book series on WWII.(condensed by me) Polish customs officials noticed a crate being delivered to the German consulate in the 1930's (don't remember exact year). The reason they noticed it was because the German embassy made a huge stink about it being hung up in customs. Someone with a level head realized that anything worth making that big a stink about must be worth looking at. The Germans were put off over the weekend with claims of red tape and the Polish Intelligence agency was called in. Over the weekend the crate was opened and the contents examined photographed and studied extensively enough to allow the Polish to create a replica. What they had was a version of the Enigma code machine that was being used by the Germans to foil industrial espionage. The Polish used this device to decrypt German transmissions up until the time of the invasion of Poland. Members of the Polish intelligence took the machine to France to keep it from being discovered by the Germans. When France was invaded it was taken to the British(I don't remember if it was still in the custody of the Polish or not). The British Intelligence services utilized this device for a template to create a decryption device that was basically 100 enigma machines linked together so that the number of code permutations could be advanced through more rapidly. Using this device and making changes to it as intelligence became available made a tremendous difference in the ability of the allies to carry the war to the Germans. It was particularly useful in intercepting the U-boat packs. There was even a chart showing how the shipping losses and U-boat losses changed every time the Kreigsmarine changed their codes. All of that being said, what contribution do the forum members believe the posession of the enigma device played in the counterintelligence war in Europe?