Delusions of Intelligence: Enigma, Ultra, and the End of Secure Ciphers

In 1974, the British government admitted that its WWII secret intelligence organization had read Germany’s ciphers on a massive scale. The intelligence from these decrypts influenced the Atlantic, the Eastern Front and Normandy. Why did the Germans never realize the Allies had so thoroughly penetrated their communications? As German intelligence experts conducted numerous internal investigations that all certified their ciphers’ security, the Allies continued to break more ciphers and plugg...