CODEBREAKING IN THE PACIFIC: CRACKING THE IMPERIAL JAPANESE NAVY'S MAIN OPERATIONAL CODE, JN-25

摘要

The ability to decrypt Japanese naval codes in the Second World War was of great importance to the Allied effort in the Pacific. However despite both the army and navy using the same cipher system, a series of Japanese errors led to the naval codes being successfully attacked by codebreakers even before the start of hostilities. John Mack outlines the cryptographic system, and shows how the Imperial Japanese Navy's operational codes were broken through a combination of skill and blunder.