Читать книгу Engineering Hitler's Downfall - Gwilym Roberts - Страница 41

The Japanese had different coding systems for diplomatic, naval, and army messages. Also, after a message had been decoded, it had to be translated before it could be read by most English-speaking officials. Some signals intercepted by British listening stations were sent to the UK for GC&CS cryptologists to attempt to decipher, and in 1939 John Tiltman managed to decode the then-current Japanese naval code.

Before Pearl Harbour, American, British, Australian, and Dutch cryptanalysts were listening to and trying to decode Japanese naval and other signals. The British office was originally in Hong Kong but then moved to Singapore; Colombo (in Ceylon, now Sri Lanka); and Mombasa, Kenya. Wireless reception there was particularly poor, and in 1943 it returned to Colombo. Following the Japanese invasion of Malaya, Army and RAF decoders were based in Delhi, India.

The principal Japanese encoding system for diplomatic messages was called Purple by American cryptanalysts, while their decoding work was known as Magic. American and British officials had managed to decode some signals before Pearl Harbour. Later they were able to decipher most Japanese messages. The Russians also succeeded in breaking into the Purple system in late 1941; the messages revealing that Japan was only going to attack the US and UK territories allowed Joseph Stalin to move considerable forces from the Far East just in time to help stop the final German push to Moscow.