Meanwhile, efforts against the Japanese PURPLE system proved the crucial
difference in the Pacific. One of our earliest hires at NSA, Solomon
Kullback, made significant findings in statistics and probability which
allowed advances against the Japanese systems. The breaking of the PURPLE
code enabled our success at the Battle of Midway, and saved countless lives.
Remember, U.S. cryptanalysts never saw a PURPLE machine, and had no concept
of how it operated. By applying advanced math and mathematical analysis they
were able to reconstruct the machine, and helped bring an early end to the
war. Australia remains intact today largely because of our efforts against
PURPLE.