How the U.S. Cracked Japan's 'Purple Encryption Machine' at the Dawn of World War II

When one thinks about cryptography or encryption in World War II, the first thing that comes to mind is the Enigma Machine used by the Nazis, whose code was broken by the Allies and used as a secret tactical advantage. But what many people don’t know is that just before World War II, the Japanese also developed a series of encryption devices that improved upon the Enigma Machine and were used to transport their top level military secrets. Here's the unknown story of how U.S. intelligence was able to crack the Japanese Purple Machine.