He was part of a team instrumental in breaking Japanese naval codes.
The Japanese were unaware that the United States had broken their naval code.
The B-Dienst, created in the early 1930s, had broken the most widely used British naval code by 1935.
By the end of the war, the Allies were regularly breaking and reading German naval codes.
John Walker walked into the same embassy to sell United States naval codes.
He allegedly lacked the necessary naval codes, however, and was finally forced to engage Sydney.
Wasn't that the text she had just read in what she had suggested might be made into a secret naval code?
Roosevelt, for instance, failed to give priority to breaking Japanese naval codes in 1940-41.
The naval code proved harder to crack; that was Sir Harry's achievement.
The British, having broken the German naval wireless code, were aware of the flight and mission.
