Years ago I read the book "Silk and Cyanide" which was a very good book about Bletchley Park and code breaking during WWII. If you have not read it, I recommend it, though the beginning of the book is a little slow read, once you get into the details later in the book you learn a lot about how things happened back then. When I heard a review on TV today about a movie called "The Imitation Game" it reminded my of the book "Silk and Cyanide" and I had to find out if it was available on my cable, and it was for free. While there were some topics in the movie that I do not care for, in general it is a very good movie that shows what went on with the British and code breaking during WWII, and how important a secret it was, and the extremes they went through to keep it a secret to get the most use out of it to win the war. If you are into understanding the strategies the Allies and in-particular the British had to use back then I recommend you watch it.