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The Rise of the NSA | 199 Europe, President Franklin D. Roosevelt reactivated the operation as the Signal Security Agency. It proved its value in breaking the Japanese machine-generated cipher “Purple.” In June 1942, using deciphered Japanese messages to pinpoint the location of the Japa- nese fleet at Midway, America won a decisive naval victory in the Pacific. Germany’s Enigma encoding machines, with three encoding wheels, proved more of a challenge. Initially, British cryptanalysts led by the brilliant mathematician Alan Turing succeeded in build- ing a rudimentary computer to decipher Germany’s messages to its submarines and bombers, but in 1942 Germany added a fourth set of encoding wheels, escalating what was essentially a battle of machine intelligence. The U.S. Navy then contracted with the National Cash Register Company to build a computing machine capable of break- ing the improved Enigma, and in May 1943 it succeeded. By the time the war ended in 1945, the United States had over one hundred giant decryption machines in operation. This unrivaled capability to read the communications of foreign nations, which remained one of America’s most closely guarded secrets, was trans- ) ferred to the Army Security Agency based at Fort Meade, Mary- © land. Then, on October 24, 1952, President Harry S. Truman greatly expanded its purview and changed its name to the National Security Agency. The NSA was given two missions. The first one was protecting the communications of the U.S. government. The main risk was that the Soviets would find a way of breaching U.S. government chan- nels of communications. The second mission was intercepting all the relevant communications and signals of foreign governments. This latter mandate included the governments of allies as well as enemies. The president, the other intelligence services, and the Department of Defense deemed what was relevant for national security. Even though the NSA remained part of the Department of Defense, its job went far beyond providing military intelligence. It also acted as a service agency to other American intelligence services. They pre- pared shopping lists of foreign communications intelligence targets for the NSA to pursue. As the Cold War heated up in the 1960s, the NSA provided intel- ligence not only to the Pentagon but to the Department of State, the | | Epst_9780451494566_2p_all_r1.indd 199 ® 9/3016 8:13AM | | HOUSE_OVERSIGHT_019687