Central Bureau
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The Central Bureau was one of two Allied signals intelligence (SIGINT) organisations in the South West Pacific area (SWPA) during
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
. Central Bureau was attached to the headquarters of the Allied Commander of the South West Pacific area, Douglas MacArthur. Central Bureau's role was to research and
decrypt In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can deci ...
intercepted
Imperial Japanese Army The was the official ground-based armed force of the Empire of Japan from 1868 to 1945. It was controlled by the Imperial Japanese Army General Staff Office and the Ministry of the Army, both of which were nominally subordinate to the Emperor o ...
(land and air) traffic and work in close co-operation with other SIGINT centres in the USA, United Kingdom and India. Air activities included both army and navy air forces, as there was no independent Japanese Air Force. The other unit was the joint
Royal Australian Navy The Royal Australian Navy (RAN) is the principal naval force of the Australian Defence Force (ADF). The professional head of the RAN is Chief of Navy (CN) Vice Admiral Mark Hammond AM, RAN. CN is also jointly responsible to the Minister of ...
/
United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
Fleet Radio Unit Fleet Radio Units (FRU) were the major centers for Allied cryptological and signals intelligence during the Pacific Campaign of World War II. Initially two FRUs were established in the Pacific, one at Pearl Harbor, Hawaii, called Station HYPO or F ...
,
Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...
(
FRUMEL Fleet Radio Unit, Melbourne (FRUMEL) was a United States–Australian–British signals intelligence unit, founded in Melbourne, Australia, during World War II. It was one of two major Allied signals intelligence units called Fleet Radio Units in t ...
), which reported directly to C-in-C, Pacific (Admiral
Chester Nimitz Chester William Nimitz (; February 24, 1885 – February 20, 1966) was a fleet admiral in the United States Navy. He played a major role in the naval history of World War II as Commander in Chief, US Pacific Fleet, and Commander in C ...
) in Hawaii and the Chief of Naval Operations (Admiral
King King is the title given to a male monarch in a variety of contexts. The female equivalent is queen, which title is also given to the consort of a king. *In the context of prehistory, antiquity and contemporary indigenous peoples, the tit ...
) in Washington.


Background

General Douglas MacArthur had his own signals intelligence unit, Station 6, while he was in command in the
Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...
before the War started, and was not fully dependent on the U.S. Navy for that type of information. However, most of the signals intelligence he received was from the Navy unit,
Station CAST Station CAST was the United States Navy signals monitoring and cryptographic intelligence fleet radio unit at Cavite Navy Yard in the Philippines, until Cavite was captured by the Japanese forces in 1942, during World War II. It was an important p ...
, originally at Cavite in the Manila Navy Yard, and evacuated to
Corregidor Island Corregidor ( tl, Pulo ng Corregidor, ) is an island located at the entrance of Manila Bay in the southwestern part of Luzon in the Philippines, and is considered part of the Province of Cavite. Due to this location, Corregidor has historically b ...
after Japanese successes. Prior to the war, it had to be sent by courier, which caused some delay and annoyance. General MacArthur escaped from Corregidor in the Philippines in a PT boat to Mindanao and flew to Australia from Del Monte on a Boeing B-17 Flying Fortress. He made his way to Melbourne, arriving there on 22 March
1942 Events Below, the events of World War II have the "WWII" prefix. January * January 1 – WWII: The Declaration by United Nations is signed by China, the United Kingdom, the United States, the Soviet Union, and 22 other nations, in w ...
. The Signals Intelligence units operating in Australia at the time of MacArthur's arrival in Melbourne were as follows: * No. 4 Australian Special Wireless Section at Park Orchards near Ringwood in Melbourne * A small Diplomatic and Press intercept section at Park Orchards * A Diplomatic cryptographic and intelligence section at Victoria Barracks, Melbourne * Some British Army Signals personnel from the
Far East Combined Bureau The Far East Combined Bureau, an outstation of the British Government Code and Cypher School, was set up in Hong Kong in March 1935, to monitor Japanese, and also Chinese and Russian (Soviet) intelligence and radio traffic. Later it moved to Sing ...
who had escaped from Java * A small
RAAF "Through Adversity to the Stars" , colours = , colours_label = , march = , mascot = , anniversaries = RAAF Anniversary Commemoration ...
Intercept section in Darwin * A small RAN intercept and Direction Finding (D/F) organisation * A small RAN cryptographic and intelligence section at the Navy Office in Melbourne and, eventually, after evacuation from Corredigor by submarine, * the personnel of Station CAST, the US Navy SIGNIT group in the Far East One of his first decisions when he arrived in Melbourne was to expand the SIGINT operations already existing in Australia. Some personnel of the United States Navy crypto group in the Philippines, evacuated in early January 1942, was operating in Melbourne. They were responsible for channeling all SIGINT information to
OP-20-G OP-20-G or "Office of Chief Of Naval Operations (OPNAV), 20th Division of the Office of Naval Communications, G Section / Communications Security", was the U.S. Navy's signals intelligence and cryptanalysis group during World War II. Its mission ...
in Washington. Brigadier General Spencer B. Akin, MacArthur's Chief Signals Officer held discussions with Major General Colin Simpson. They agreed that a Research and Control Centre to handle Signals Intelligence (SIGINT) was needed. MacArthur subsequently issued orders for the formation of two complementary groups: * An intercept organisation known initially as No. 5 Wireless Section * A research and control centre known as the Central Bureau. Initially Central Bureau was made up of 50% American, 25% Australian Army and 25% RAAF personnel. Hence the Central Bureau was an unusual cryptographic organisation, coming under the direct command of an area commander (MacArthur) rather than reporting to a central cryptographic organisation; as confirmed by
Marshall Marshall may refer to: Places Australia * Marshall, Victoria, a suburb of Geelong, Victoria Canada * Marshall, Saskatchewan * The Marshall, a mountain in British Columbia Liberia * Marshall, Liberia Marshall Islands * Marshall Islands, an i ...
's reply. This decision led to periodic ructions in the American military establishment about MacArthur's command having its own cryptographic service under his command; a privilege that he jealously guarded.


Liaison with

FRUMEL Fleet Radio Unit, Melbourne (FRUMEL) was a United States–Australian–British signals intelligence unit, founded in Melbourne, Australia, during World War II. It was one of two major Allied signals intelligence units called Fleet Radio Units in t ...

MacArthur was not happy to depend on the Navy's discretion in handling his SIGINT requirements. He felt he had experienced problems with such an arrangement when he was in
Manila Manila ( , ; fil, Maynila, ), officially the City of Manila ( fil, Lungsod ng Maynila, ), is the capital of the Philippines, and its second-most populous city. It is highly urbanized and, as of 2019, was the world's most densely populate ...
. MacArthur's Intelligence Officer (G-2) was Major General Charles A. Willoughby. In Australia the rules laid down by Cmdr Rudy Fabian the head of FRUMEL (through Admiral Leary) for receiving
FRUMEL Fleet Radio Unit, Melbourne (FRUMEL) was a United States–Australian–British signals intelligence unit, founded in Melbourne, Australia, during World War II. It was one of two major Allied signals intelligence units called Fleet Radio Units in t ...
briefings said that Fabian or his representative were to brief MacArthur and his chief of staff Richard K. Sutherland at 1400 each day, but could not copy or distribute the material. The representative was not to be kept waiting. Only MacArthur and Sutherland were to be present; Willoughby, his G2 was excluded. Once Fabian burnt a document in front of Willoughby on his way out and dropped the ashes in his bin to demonstrate that he was not allowed to see it! A message on 9 April 1942 indicated that the "RZP Campaign" against
Port Moresby (; Tok Pisin: ''Pot Mosbi''), also referred to as Pom City or simply Moresby, is the capital and largest city of Papua New Guinea. It is one of the largest cities in the southwestern Pacific (along with Jayapura) outside of Australia and New ...
was to be an invasion not an air raid and which would isolate Australia from America. Fabian at
FRUMEL Fleet Radio Unit, Melbourne (FRUMEL) was a United States–Australian–British signals intelligence unit, founded in Melbourne, Australia, during World War II. It was one of two major Allied signals intelligence units called Fleet Radio Units in t ...
briefed MacArthur who was "incredulous" as he expected the target would be New Caledonia, so Fabian explained the (
JN-25 The vulnerability of Japanese naval codes and ciphers was crucial to the conduct of World War II, and had an important influence on foreign relations between Japan and the west in the years leading up to the war as well. Every Japanese code was e ...
) code-breaking process and showed him the Japanese commander’s intercepted message with the objectives to restrict enemy fleet movements and attack the north coast of Australia. So a transport due to leave the next day for New Caledonia was sent to Port Moresby. On 23 April Fabian showed MacArthur that the IJN was amassing a large force at Truk, and planned to occupy Tulagi also. MacArthur got an Australian reconnaissance plane to "discover" the Port Moresby invasion force on 5 May, leading to the Battle of the Coral Sea. On 19 and 23 May messages indicated that the Japanese were proposing to land at Buna and go overland over the Owen Stanley Range via the
Kokoda Track The Kokoda Track or Trail is a single-file foot thoroughfare that runs overland – in a straight line – through the Owen Stanley Range in Papua New Guinea (PNG). The track was the location of the 1942 World War II battle between Japanes ...
to Port Moresby; though MacArthur, Willoughby and Blamey were unconvinced saying "Nobody in their right senses would land there". Blamey took "minimal precautions" to defend the track, resulting in heavy losses for the 39th Battalion sent there.


Central Bureau's origins

Central Bureau was a joint US-Australian signal intelligence organisation, established on 15 April 1942 under the command of US Army Major General Spencer B. Akin, with headquarters in
Melbourne Melbourne ( ; Boonwurrung/Woiwurrung: ''Narrm'' or ''Naarm'') is the capital and most populous city of the Australian state of Victoria, and the second-most populous city in both Australia and Oceania. Its name generally refers to a met ...
. General MacArthur advised Washington of his decision in a dispatch on 1 April 1942. He described the role of the group as "the interception and cryptanalyzing of Japanese intelligence". A small Naval cryptographic group also became part of the secret new unit. It was led by Commander
Eric Nave Captain Eric Nave (18 March 1899 – 23 June 1993) was an Australian cryptographer and intelligence officer in the Royal Australian Navy (RAN) and Royal Navy, noted for his work with joint Allied intelligence units during World War II. He serv ...
, who with Professor
Dale Trendall Arthur Dale Trendall, (28 March 1909 – 13 November 1995) was a New Zealand art historian and classical archaeologist whose work on identifying the work of individual artists on Greek ceramic vessels at Apulia and other sites earned him in ...
had been working on Japanese diplomatic and naval codes at Victoria Barracks. Central Bureau was established in a gabled, ivy-clad mansion called "Cranleigh" in Domain Road, at
South Yarra South Yarra is an inner-city suburb in Melbourne, Victoria, Australia, 4 km south-east of Melbourne's Melbourne central business district, Central Business District, located within the Cities of City of Melbourne, Melbourne and City of Sto ...
, Melbourne. Central Bureau's role was to research and decrypt army and air intercept traffic and work in close co-operation with other SIGINT centres in the USA, United Kingdom and India. Mic Sandford was appointed AIF Commanding Officer at Central Bureau. Major General Akin's Executive Officer, Major (later Colonel) Joe R. Sherr had been evacuated from the Philippines (Station 6). He was responsible for arranging for the first group of US "SIGINT" personnel to come to Australia, and as Akin's control was indirect he was responsible for day-to-day running of the bureau. He was killed when returning from a liaison visit to the
wireless Experimental Centre The Wireless Experimental Centre (WEC) was one of two overseas outposts of Station X, Bletchley Park, the British signals analysis centre during World War II. The other outpost was the Far East Combined Bureau. Codebreakers Wilfred Noyce and Mauri ...
in India, when his aircraft crashed 3 km from Calcutta airfield on 21 September 1943. Sandford had wanted to send "Pappy" Clark to the conference but Akin said that MacArthur would not agree to send Clark (only a major) and so sent Colonel Sherr instead. He was succeeded by Major Abraham "Abe" Sinkov, a mathematician, who was appointed assistant director of Central Bureau. Sinkov had previously been a senior cryptographer in the US Army Signals Intelligence Service under
William F. Friedman William Frederick Friedman (September 24, 1891 – November 12, 1969) was a US Army cryptographer who ran the research division of the Army's Signal Intelligence Service (SIS) in the 1930s, and parts of its follow-on services into the 1950s. ...
. Sinkov had previously been in charge of an intercept station in Panama. He had visited Britain in 1941 to facilitate the exchange of cryptographic information. With Sinkov (US Army), the three assistant directors were Australians Alistair "Mic" Sandford (Major then Lt-Col, Second AIF) and Roy Booth (Squadron Leader then Wing Commander, RAAF). They acted as head of their respective service organisations; with Sandford the bureau executive officer under Sherr, then Booth from 1944. The bureau functioned well and harmoniously, with job demarcation as Australian experience was from wireless interception and traffic analysis in the Middle East and the Americans in breaking codes and cyphers, although this "broke down" as the war went on. Signals organisations tend to be "meritocratic" rather than on rank. Experienced intercept
Kana The term may refer to a number of syllabaries used to write Japanese phonological units, morae. Such syllabaries include (1) the original kana, or , which were Chinese characters (kanji) used phonetically to transcribe Japanese, the most p ...
operators from a
Royal Australian Air Force "Through Adversity to the Stars" , colours = , colours_label = , march = , mascot = , anniversaries = RAAF Anniversary Commemoration ...
unit at
Townsville Townsville is a city on the north-eastern coast of Queensland, Australia. With a population of 180,820 as of June 2018, it is the largest settlement in North Queensland; it is unofficially considered its capital. Estimated resident population, 3 ...
were assigned to the new Central Bureau. The RAAF at the time had a number of Kana operators being trained and were about to train a further 13 WAAAF personnel. (
Katakana is a Japanese syllabary, one component of the Japanese writing system along with hiragana, kanji and in some cases the Latin script (known as rōmaji). The word ''katakana'' means "fragmentary kana", as the katakana characters are derived f ...
is one of the syllabic forms of written Japanese). The cryptanalysts who had operated from the
Malinta Tunnel The Malinta Tunnel is a tunnel complex built by the United States Army Corps of Engineers on the island of Corregidor in the Philippines. It was initially used as a bomb-proof storage and personnel bunker, but was later equipped as a 1,000- ...
during the Battle of Corregidor got out to Australia by submarine in two groups. Their equipment was pushed into
Manila Bay Manila Bay ( fil, Look ng Maynila) is a natural harbor that serves the Port of Manila (on Luzon), in the Philippines. Strategically located around the capital city of the Philippines, Manila Bay facilitated commerce and trade between the Phi ...
. They were used to assist the Australian Wireless Group units. A group of cryptographic, cryptanalytic and translator personnel from the Japanese section of the Washington Signal Intelligence Service were also moved to Australia. More Australians were also recruited to Central Bureau after it was established.


Structure

Central Bureau comprised: * administrative personnel * supply personnel * cryptographic personnel * cryptanalytic personnel * interpreters * translators * a field section which included the intercept and communications personnel On 25 April 1942 the small RAAF Intercept Station operating in two
back-to-back houses Back-to-backs are a form of terraced houses in the United Kingdom, built from the late 18th century through to the early 20th century in various guises. Many thousands of these dwellings were built during the Industrial Revolution for the rapidl ...
at 21 Sycamore Street and 24 French Street in the suburb of Pimlico in Townsville was given its new name of No. 1 Wireless Unit and became part of Central Bureau. The newly named Unit included 7 RAAF, 1 AMF and 4 United States Army personnel in No. 1 Wireless Unit at Townsville. This RAAF Unit had started earlier in March 1942 as a small intercept station located in the initial two houses at Pimlico under Wing Commander Booth. By 6 July 1942 the intercept operator numbers at Central Bureau had increased from six to twenty nine. Commander
Nave The nave () is the central part of a church, stretching from the (normally western) main entrance or rear wall, to the transepts, or in a church without transepts, to the chancel. When a church contains side aisles, as in a basilica-type ...
moved to Central Bureau in mid-1942 from the combined Australian Navy/U.S. Navy operation in Melbourne known as
FRUMEL Fleet Radio Unit, Melbourne (FRUMEL) was a United States–Australian–British signals intelligence unit, founded in Melbourne, Australia, during World War II. It was one of two major Allied signals intelligence units called Fleet Radio Units in t ...
, which came under U.S. Navy control (Lt Rudy Fabian) in mid-1942. Fabian thought Nave had breached security, and got rid of Nave and the civilians (including Professor
Thomas Room Thomas Gerald Room FRS FAA (10 November 1902 – 2 April 1986) was an Australian mathematician who is best known for Room squares. He was a Foundation Fellow of the Australian Academy of Science. . Also published in ''Historical Records of A ...
, who also went to Central Bureau); the Holden Agreement specifically stated that
Eric Nave Captain Eric Nave (18 March 1899 – 23 June 1993) was an Australian cryptographer and intelligence officer in the Royal Australian Navy (RAN) and Royal Navy, noted for his work with joint Allied intelligence units during World War II. He serv ...
was not to work at
FRUMEL Fleet Radio Unit, Melbourne (FRUMEL) was a United States–Australian–British signals intelligence unit, founded in Melbourne, Australia, during World War II. It was one of two major Allied signals intelligence units called Fleet Radio Units in t ...
, indicating that Fabian had "friends in high places". Although Nave headed up the "Solutions" division there, most records indicate he personally dealt with minor Japanese naval codes and simple substitution ciphers in spite of his Japanese language capability and long history with Japanese codes. However Duffy wrote that ''Nave was actively working on
JN-25 The vulnerability of Japanese naval codes and ciphers was crucial to the conduct of World War II, and had an important influence on foreign relations between Japan and the west in the years leading up to the war as well. Every Japanese code was e ...
until the day he was expelled from Monterrey''. Colonel Sinkov and his American staff worked on the high-level Japanese Army codes. Central Bureau did not break any high level Japanese Army codes until mid-1943 success with the Water Transport Code. In January 1944, one main line Japanese Army code was broken with help from a buried trunk found at Sio,
New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torr ...
, left by retreating Japanese Army troops of the 20th Division. The Bureau spent a day drying the damp pages, and the flood of decoded messages that ensued meant that MacArthur has to ask the US Navy for assistance (the Japanese thought that the papers had been destroyed). On 20 July 1942, General MacArthur moved his headquarters to
Brisbane Brisbane ( ) is the capital and most populous city of the Australian state of Queensland, and the third-most populous city in Australia and Oceania, with a population of approximately 2.6 million. Brisbane lies at the centre of the South ...
. A separate American intelligence operation was located nearby in a building called "Palma Rosa" at 9 Queens Road,
Hamilton Hamilton may refer to: People * Hamilton (name), a common British surname and occasional given name, usually of Scottish origin, including a list of persons with the surname ** The Duke of Hamilton, the premier peer of Scotland ** Lord Hamilt ...
. "Palma Rosa" was commandeered by the Counter Intelligence Corps, G-2 Section, Headquarters U.S. Army Forces in the Far East (U.S.A.F.F.E.). Central Bureau also relocated to Brisbane in September, with the American contingent of six officers and eighteen enlisted men moving first. The bureau moved to the suburb of Ascot, not far from the new American airfield at
Eagle Farm Airport Eagle Farm Airport was a small airport located north-east of Brisbane in the suburb of Eagle Farm, Queensland, Australia. History An area located near Eagle Farm Racecourse was initially used as a landing field in 1922 and Eagle Farm Aero ...
. Staff were accommodated as boarders in private homes or in military camps with daily transport by truck or bus. Officers obtained rented accommodation around Ascot and nearby suburbs. Mic Sandford the head of the Australian Army contingent rented a house at 50 Elderney Terrace in nearby
Hamilton Hamilton may refer to: People * Hamilton (name), a common British surname and occasional given name, usually of Scottish origin, including a list of persons with the surname ** The Duke of Hamilton, the premier peer of Scotland ** Lord Hamilt ...
; this became a social centre and the scene of frequent dinner and drinking parties. The CB headquarters was in "Nyrambla", a huge house at 21 Henry Street built as a grand mansion in 1886, although the large 6 ha section was subdivided from 1905 and the house was converted into flats in the late 1920s. The house still retained rooms with marble fireplaces, ornate plaster and 4.8m high ceilings, and the building remained the main administrative and training centre for the bureau. When the bureau assumed an augmented role to coordinate land and air forces signals intelligence, additional facilities were located a few minutes walk away at a small public park opposite the Ascot railway station Hence it became known as "Ascot Park" although officially called "Oriel Park". Between the station, Kitchener Road and Lancaster Road, the park had nearly 20 temporary army wooden huts by mid-1943 and 31 by September 1945. Across the road at 77 Kitchener Road a disused brick Fire Station was used for banks of IBM
punched card A punched card (also punch card or punched-card) is a piece of stiff paper that holds digital data represented by the presence or absence of holes in predefined positions. Punched cards were once common in data processing applications or to di ...
equipment used by cryptanalysts to analyze intercepted cyphertext. The machines had been in the garage at the rear of 21 Henry Street but the noise from all-hours operation bought complaints from neighbours. When the IBM machines were removed from 21 Henry Street the garage was occupied by No. 11 Australian Cypher Section and filled with Typex machines which were operated mostly by Australian Women's Army Service (AWAS) personnel. Beginning in January 1942, U.S. Navy stations in Hawaii ( Station HYPO), Cavite/Corregidor (
Station CAST Station CAST was the United States Navy signals monitoring and cryptographic intelligence fleet radio unit at Cavite Navy Yard in the Philippines, until Cavite was captured by the Japanese forces in 1942, during World War II. It was an important p ...
) and OP-20-G ( Station NEGAT, at Washington) began issuing formal intelligence decrypts far in advance of the U.S. Army or Central Bureau. FRUMEL in Australia obtained IBM equipment in 1942 to replace that which had been left behind in Manila Bay on leaving Corregidor and employed it throughout their tenure in Melbourne. Japanese POW's were interrogated by the ATIS at a house called "
Tighnabruaich Tighnabruaich; (; gd, Taigh na Bruaich) is a village on the Cowal peninsula, on the western arm of the Kyles of Bute in Argyll and Bute, Scotland. In 2011 the population was 660. It is west of Glasgow and north of the Isle of Arran. Tighnabrua ...
" at
Indooroopilly Indooroopilly is a riverside suburb 7km west of the Brisbane CBD, Queensland, Australia. In the , Indooroopilly had a population of 12,242 people. Geography Indooroopilly is bounded to the south and south-east by the median of the Brisbane Ri ...
in Brisbane. Central Bureau at 21 Henry Street, Ascot, in Brisbane decrypted a Japanese Army Air/Ground signal intercepted by 51 Wireless Section in Darwin that contained Admiral
Isoroku Yamamoto was a Marshal Admiral of the Imperial Japanese Navy (IJN) and the commander-in-chief of the Combined Fleet during World War II until he was killed. Yamamoto held several important posts in the IJN, and undertook many of its changes and reor ...
's itinerary for an upcoming trip to Rabaul. Admiral Yamamoto, was the Commander in Chief of the Combined Japanese Fleet, the architect of the attack on
Pearl Harbor Pearl Harbor is an American lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. It was often visited by the Naval fleet of the United States, before it was acquired from the Hawaiian Kingdom by the U.S. with the signing of the R ...
. Central Bureau reportedly sent the decrypted message to FRUMEL where it was reportedly translated by a U.S. Navy linguist. Although Central Bureau may have decrypted the message, the interception of his flight was based on decrypts of Japanese naval messages by FRUPAC/Station HYPO in Hawaii, FRUMEL, OP-20-G in Washington and Station AL on Guadalcanal. Major Lasswell USMC in Hawaii decrypted the Japanese Naval message first and Captain Layton (Pacific Fleet Intelligence in Hawaii) gave it to Admiral Nimitz who authorized a shootdown attempt after determining from ComNavAirSoPac that it could be done with by one of his Army Air Corp units on Guadalcanal. Central Bureau is the precursor to the Defense Signals Bureau, which after a number of name changes is (from 2013) called the Australian Signals Directorate.


References


Bibliography

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Further reading

* * * *{{cite book , last = Prados , first = John , year = 1995 , title = Combined Fleet Decoded: The Secret History of American Intelligence and the Japanese Navy in World War II , publisher = Random House , location = New York , isbn = 0-679-43701-0 Military history of Australia during World War II Australian intelligence agencies History of cryptography Signals intelligence agencies Military communications of Australia Signals intelligence of World War II