Far East Combined Bureau

Far East Combined Bureau (FECB), a British inter-service intelligence organization formed in Hong Kong in 1935. Its radio intelligence facilities included radio finger printing, several (huff-duff) stations, a Y service station, and a naval and military cryptanalysis section. In August 1939 it moved to Singapore, but once Japan entered the war in December 1941 its army and RAF sections returned to their respective services, and it virtually ceased to exist. However, the name continued to be used for the organization's largest section, the naval one, which was moved to Colombo, Ceylon. In March 1942, this station intercepted and partially deciphered a signal which indicated the Japanese Navy intended raiding Ceylon (see Indian Ocean). The section then went with Somerville's Eastern Fleet to Mombasa (Kilindini) in Kenya but returned to Colombo in 1943.

The FECB's records were probably destroyed and opinions vary as to how much the Bureau contributed to breaking the Japanese Navy's JN-25 cipher (see ULTRA, 2). According to one authority ( D. Horner, High Command: Australia and Allied Strategy, 1939–1945, Sydney, 1982, p. 225) the British supplied the cipher's key to the US Navy in 1940, and the official historian of British intelligence confirms that sufficient progress had been made in breaking the cipher to enable the British to monitor the Japanese fleet's main movements (see F. Hinsley et al., British Intelligence in the Second World War, Vol. 1, London, 1979, p. 53 n). However, this ability was lost when the Japanese altered the key prior to their raid on Pearl Harbor.