Japanese sources

Japanese sources

In the Pacific theater, the Japanese cipher machine dubbed "Purple" by the Americans, and unrelated to the Enigmas, was used for highest-level Japanese diplomatic traffic. It was also cracked by the US Army's Signal Intelligence Service and disseminated under the codeword MAGIC.

Some Purple decrypts proved useful elsewhere, for instance detailed reports by Japan's ambassador to Germany which were encrypted on the Purple machine. These reports included reviews of German strategy and intentions, reports on direct inspections (in one case, of Normandy beach defenses) by the ambassador, and reports of long interviews with Hitler.

The Japanese are said to have obtained an Enigma machine as early as 1937, although it is debated whether they were given it by their German ally or bought a commercial version which, except for plugboard and actual rotor wirings, was essentially the German Army / Air Force machine.