Enigma one. At Bletchley Park, some of the key people responsible for success in the Tunny effort included mathematicians W. T. "Bill" Tutte and Max Newman and electrical engineer Tommy Flowers. Italian In June 1940, the Italians were using book codes for most of their military messages, except for the Italian Navy, which in early 1941 had started using a version of the Hagelin rotor-based cipher machine C-38. This was broken from June 1941 onwards by the Italian subsection of GC&CS at Bletchley Park. Japanese In the Pacific theatre, a Japanese cipher machine, called "Purple" by the Americans, was used for highest-level Japanese diplomatic traffic. It produced a polyalphabetic substitution cipher, but unlike Enigma, was not a rotor machine, being built around electrical stepping switches. It was broken by the US Army Signal Intelligence Service and disseminated as Magic. Detailed reports by the Japanese ambassador to Germany were encrypted on the Purple machine. His reports included reviews of German assessments of the military situation, reviews of strategy and intentions, reports on direct inspections by the ambassador (in one case, of Normandy beach defences), and reports of long interviews with Hitler. The Japanese are said to have obtained an Enigma machine in 1937, although it is debated whether they were given it by the Germans or bought a commercial version, which, apart from the plugboard and internal wiring, was the German Heer/Luftwaffe machine. Having developed a similar machine, the Japanese did not use the Enigma machine for their most secret communications. The chief fleet communications code system used by the Imperial Japanese Navy was called JN-25 by the Americans, and by early 1942 the US Navy had made considerable progress in decrypting Japanese naval messages. The US Army also made progress on the Japanese Army's codes in 1943, including codes used by supply ships, resulting in heavy losses to their shipping. Distribution Army- and Air Force-related intelligence derived from signals intelligence (SIGINT) sources—mainly Enigma decrypts in Hut 6—was compiled in summaries at GC&CS (Bletchley Park) Hut 3 and distributed initially under the codeword "BONIFACE", implying that it was acquired from a well placed agent in Berlin. The volume of the intelligence reports going out to commanders in the field built up gradually. Naval Enigma decrypted in Hut 8 was forwarded from Hut 4 to the Admiralty's Operational Intelligence Centre (OIC), which distributed it initially under the codeword "HYDRO". The codeword "ULTRA"