There's a great story that Tommy Flowers tells in the book about COLOSSUS, which is that when COLOSSUS was declassified and published (sometime in the 80s) almo

There's a great story that Tommy Flowers tells in the book about COLOSSUS, which is that when COLOSSUS was declassified and published (sometime in the 80s) almost nobody cared, because history had already been written describing what the first "real" computer was. COLOSSUS used big networks of vacuum switches to break the Lorenz SZ-40 ("Tunny") teletype crypto machine used for high-level Nazi communications. Bletchley Park was very skeptical that COLOSSUS would ever work, so Flowers (who worked at the post office research lab) self-funded the work and told Churchill he could have the machine finished in a year. One person did care, though, and wrote to Flowers after reading about COLOSSUS's design. He was a former Nazi, German Army crypto specialist that told Flowers he had had basically the same idea for a code-breaking machine. However, when this German crypto specialist tried to sell the project to Hitler, he told Hitler it would take two years. Hitler vetoed the plan because he thought the war would be over by then.