Hut 7 was a wartime section of the

Government Code and Cypher School (GC&CS) Government Communications Headquarters, commonly known as GCHQ, is an intelligence and security organisation responsible for providing signals intelligence (SIGINT) and information assurance (IA) to the government and armed forces of the Uni ...

Bletchley Park Bletchley Park is an English country house and estate in Bletchley, Milton Keynes (Buckinghamshire) that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years following ...

tasked with the solution of

Japanese naval codes 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 ...

such as JN4, JN11, JN40, and

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 ...

. The hut was headed by

Hugh Foss Hugh Rose Foss (13 May 1902 – 23 December 1971) was a British cryptanalyst. At Bletchley Park during World War II he made significant contributions both to the breaking of the German Enigma code and headed the section tasked with breaking Japan ...

who reported to Frank Birch, the head of Bletchley's Naval section. Hut 7 supplied cryptanalysts and linguists to Bletchley's front line station 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 ...

(FECB) at

Hong Kong Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China (abbr. Hong Kong SAR or HKSAR), is a List of cities in China, city and Special administrative regions of China, special ...

, then

Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, bor ...

, then Anderson Station (

Colombo Colombo ( ; si, කොළඹ, translit=Koḷam̆ba, ; ta, கொழும்பு, translit=Koḻumpu, ) is the executive and judicial capital and largest city of Sri Lanka by population. According to the Brookings Institution, Colombo me ...

Ceylon Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

, now Sri Lanka), then Allidina School in

Kilindini Kilindini Harbour is a large, natural deep-water inlet extending inland from Mombasa, Kenya. It is at its deepest center, although the controlling depth is the outer channel in the port approaches with a dredged depth of . It serves as the harbo ...

Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

before moving back to Colombo. Bletchley co-operated with the US Navy Code and Signals Section known as

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 D.C., and with FRUMEL 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 metro ...

(although the reciprocal cooperation from Fabian at FRUMEL was limited and reluctant); see Central Bureau and FRUMEL.

Pre-War origins

Among the first challenges was overcoming the special

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 ...

and

romaji The romanization of Japanese is the use of Latin script to write the Japanese language. This method of writing is sometimes referred to in Japanese as . Japanese is normally written in a combination of logographic characters borrowed from Ch ...

Morse code Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one ...

system used by the Japanese. GC&CS began breaking Japanese diplomatic traffic in the early 1920s. GC&CS subsequently attacked the Naval Reporting Code, and General Operations Code. The section was headed by William "Nobby" Clarke with Harry Shaw and Ernest Hobart-Hampden.Stripp, Alan
''Codebreaker in the Far East''
London, England ; Totowa, NJ : F. Cass, 1989. . Cf
p.13
/ref> These were later joined by Eric Nave, seconded from the

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 o ...

John Tiltman Brigadier John Hessell Tiltman, (25 May 1894 – 10 August 1982) was a British Army officer who worked in intelligence, often at or with the Government Code and Cypher School (GC&CS) starting in the 1920s. His intelligence work was largely conn ...

, and

. GC&CS operated the

, the codebreaking and intercept station in

prewar, which during the war moved to

, Colombo and Kilindini.

WWII expansion

Potential linguists and cryptographers were recruited from the

University of Cambridge , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

and the

University of Oxford , mottoeng = The Lord is my light , established = , endowment = £6.1 billion (including colleges) (2019) , budget = £2.145 billion (2019–20) , chancellor ...

by referral through people like the Revd Martin Charlesworth, A.D. Lindsay, Dr

C. P. Snow Charles Percy Snow, Baron Snow, (15 October 1905 – 1 July 1980) was an English novelist and physical chemist who also served in several important positions in the British Civil Service and briefly in the UK government.''The Columbia Encyclope ...

, and Theodore Chaundy. Candidates were interviewed and approved by a board that included Colonel Tiltman. Successful candidates received a final interview at Bletchley by a senior representative of their section. At the outset of World War II, Britain had few Japanese linguists and conventional wisdom held that it would require two years to produce qualified linguists for the war effort. In February 1942, an accelerated program was established to train linguists to assist with Japanese signals intelligence. Candidates were put through an intensive six-month course taught by Captain

Oswald Tuck Instructor Captain Oswald Thomas Tuck (1 September 1876 – 26 February 1950) was a naval officer and teacher of Japanese. He served as a naval instructor in navigation and Japanese and later translated a confidential history of the Russo-Japanes ...

, RN. The course was taught in various locations in Bedford including the Gas Company. The course produced linguists for the Navy, Army, Air Force, and Foreign Office. Some of the linguists were sent on to Bletchley, while others were sent to London to work with Captain Malcolm Kennedy. Later cryptanalysts did not require linguistic training, so could be recruited and put to work directly. Some of these cryptanalysts received a shorter version of the Japanese language course. The Japanese Naval Section was originally stationed at the Elmer School near Bletchley. By August 1942, the unit consisted of 40 people. The unit was moved inside Bletchley Park in September and again in February 1943 to Hut 7. The unit expanded (or moved) later to Block B. The wooden structure of the hut was demolished sometime between 1948 and 1954.

Contributions

In addition to code books and manual ciphers, the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...

also utilized electric cipher machines known as

JADE Jade is a mineral used as jewellery or for ornaments. It is typically green, although may be yellow or white. Jade can refer to either of two different silicate minerals: nephrite (a silicate of calcium and magnesium in the amphibole group ...

and

CORAL Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and se ...

using the same technology as

PURPLE Purple is any of a variety of colors with hue between red and blue. In the RGB color model used in computer and television screens, purples are produced by mixing red and blue light. In the RYB color model historically used by painters ...

. While OP-20-G took the lead on these systems, Bletchley provided some contributions. In 1921, GC&CS was able to provide insight into the Japanese bargaining position at the

Washington Naval Conference The Washington Naval Conference was a disarmament conference called by the United States and held in Washington, DC from November 12, 1921 to February 6, 1922. It was conducted outside the auspices of the League of Nations. It was attended by nine ...

of the nine major powers and limit their ambitions. Pre-war accomplishments were helped tremendously by the death of

Emperor Taishō was the 123rd Emperor of Japan, according to the traditional order of succession, and the second ruler of the Empire of Japan from 30 July 1912 until his death in 1926. The Emperor's personal name was . According to Japanese custom, while reigni ...

in 1926. The repetition of the formal announcement provided GC&CS with cribs into almost every code in use. Later in 1934, Foss was able to break an early Japanese cipher machine. Tiltman provided the major break into JN25 in 1939. In early 1942, decrypts from Anderson gave advance warning of Vice Admiral Nagumo's

Indian Ocean raid The Indian Ocean raid, also known as Operation C or Battle of Ceylon in Japanese, was a naval sortie carried out by the Imperial Japanese Navy (IJN) from 31 March to 10 April 1942. Japanese aircraft carriers under Admiral Chūichi Nagumo ...

including a planned attack on Colombo. The warning allowed the British to limit damage, improve opposition, and evacuate the fleet and the cryptanalysts from Colombo to Kilindini. In May 1945, the team at HMS Anderson successfully broke a message in JN25 that provided details of a supply convoy going from Singapore to the Andaman Islands. This message provided details that led to the sinking of the

Japanese cruiser Haguro ''Haguro'' (羽黒) was a heavy cruiser of the Imperial Japanese Navy, named after Mount Haguro in Yamagata Prefecture. Commissioned in 1929, ''Haguro'' saw significant service during World War II, participating in nine naval engagements. She ...

in the

Battle of the Malacca Strait The Battle of the Malacca Strait, sometimes called the Sinking of ''Haguro'', and in Japanese sources as the Battle off Penang (ペナン沖海戦), was a naval battle that resulted from the British search-and-destroy operation in May 1945, calle ...

List of Hut 7 personnel

The following people served in Hut 7, HMS Anderson, and Kilindini: * Sidney Abramson, translator at Anderson * Brian Augarde, mathematician, sub-section chief at Bletchley, worked on JN11 *

Peter Barnett Peter may refer to: People * List of people named Peter, a list of people and fictional characters with the given name * Peter (given name) ** Saint Peter (died 60s), apostle of Jesus, leader of the early Christian Church * Peter (surname), a sur ...

, translator at Anderson * Lieutenant-Commander Barnham, translator at Kilindini *

Charles Bawden Charles Roskelly Bawden, FBA (22 April 1924 – 11 August 2016) was a professor of the Mongolian language in the School of Oriental and African Studies (SOAS) at the University of London from 1970 to 1984. Early years Charles Bawden was b ...

, linguist at Anderson * Ted Biggs, ex-diplomat, Kilindini, Anderson, and Melbourne * Gerry Brennan, cryptanalyst at Bletchley, worked on JN40 * Leo Brouwer, Lieutenant-Commander RNN; a Japanese linguist from Kamer 14 (Java); Colombo, Kilindini, Hut 7 * Maurice Burnett, linguist at Anderson * John Catlow, linguist at Anderson * Dudley Cheke, Kilindini * Jon Cohen, linguist/cryptanalyst temporarily assigned to Diplomatic Section, later to Bletchley, and Kilindini * Lieutenant-Commander E.H. Colgrave * George Curnock, translator at Singapore, Anderson and Kilindini * Brenda Scott Curtis, cryptanalyst Bletchley Park * Wynn Davies, translator/cryptanalyst at Bletchley and Kilindini * Denny Denham, translator at Anderson * Hugh Denham, cryptanalyst at Bletchley, Kilindini, and Anderson, worked on JN25 * Alan Douglas, linguist temporarily assigned to Diplomatic Section * John English, sub-section chief at Bletchley * Harry Field, Anderson * Frederick (Freddy) Freeborn, head of the Hollerith index section in Hut 7 (later Block C), ex-head of BTM's Letchworth factory. * Forman, Kilindini *

, head of Hut 7 * Daphne Goff, Foreign Office, Hollerith operator * Diana Goff, Foreign Office, Hollerith operator * Christy Maggie Mackinnon, Foreign Office, Hollerith operator * Capt. Joshua David Goldberg, Japanese codebreaker * Sergeant Harris-Jones, assistant translator at Bletchley * Hubert Eustace Hooper, linguist at Anderson * George Hunter, linguist at Anderson * Hayden John, cryptanalyst, ran JN40 group at Bletchley * Lieutenant-Commander Bruce Keith, translator at Bletchley * Sub Lieutenant Anthony Richard Michael Kelly (RNVR), linguist - Japanese * Johnnie Lambert, cryptanalyst at Bletchley and Anderson *

Peter Laslett Thomas Peter Ruffell Laslett (18 December 1915 – 8 November 2001) was an English historian. Biography Laslett was the son of a Baptist minister and was born in Bedford on 18 December 1915. Although he spent much of his childhood in Oxford, ...

, cryptanalyst at Bletchley, worked on JN11 *Elsie May Lait, Hut 7 FO civilian * Peter Lawrence, translator at Anderson * John Lloyd, language instructor at Bletchley *

Michael Loewe Michael Arthur Nathan Loewe (born 2 November 1922) is a British Sinologist, historian, and writer who has authored dozens of books, articles, and other publications in the fields of Classical Chinese as well as the history of ancient and ear ...

, linguist/cryptanalyst at Bletchley and Kilindini * Alexander Murray Macbeath, cryptanalyst at Bletchley. * John MacInnes, cryptanalyst at Kilindini * Norman Mahalski (later Scott), mathematician / cryptanalyst at Bletchley and Anderson, worked on JN11 and JN25 * Commander McIntyre RN, translator, at Kilindini and ran JN25 group at Bletchley * Joan Meikle, Foreign Office, Bletchley * Alan Merry, translator at Melbourne, Kilindini, and ran JN40 group at Anderson * Milner, support at Anderson * George Mitchell, Anderson * Alexander Sandy Morris, Anderson * Lieutenant Commander Philip L Nicol RN, linguistics and Cryptanalyst - Japanese at Bletchley. * Commander Parsons RN, translator at Kilindini * Jimmy Pollard, cryptanalyst at Bletchley, worked on JN40 * Pond, support at Anderson * Fred Ponting, cryptanalyst at Bletchley, worked on JN11 * John Sharman, cryptanalyst at Anderson and Kilindini *

John Silkin John Ernest Silkin (18 March 1923 – 26 April 1987) was a British left-wing Labour politician and solicitor. Early life He was the third son of Lewis Silkin, 1st Baron Silkin, and a younger brother of Samuel Silkin, Baron Silkin of Dulwic ...

, linguist at Anderson * Stanton, cryptanalyst at Kilindini * John Sutcliffe, cryptanalyst at Bletchley * Patrick Taylor, mathematician at Bletchley * Wilf Taylor, linguist at Anderson * Captain Dick Thatcher RN, worked on JN 25 at Bletchley, was at

FECB 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 ...

Hong Kong * Brian Townend, cryptanalyst at Kilindini, contributed a break into JN40 *

Richard Wolfe Richard Daniel Wolfe (1975-27 May 2016) was a Canadian gangster who co-founded the Indian Posse gang along with his younger brother Danny Wolfe in 1988, which he later left in 1997. Convicted of attempted murder in 1995, he was released on parole ...

, Anderson * Leslie Yoxall, cryptanalyst at Bletchley, previously working in Hut 8

References

{{DEFAULTSORT:Hut 07 Cryptography organizations Bletchley Park Buildings and structures in Milton Keynes Huts