Hugh Rose Foss (13 May 1902 – 23 December 1971) was a British

cryptanalyst Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic sec ...

. At

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 followin ...

during World War II he made significant contributions both to the breaking of the German Enigma code and headed the section tasked with breaking Japanese Naval codes.

Early life and education

Foss was born in Kobe, Japan, one of five children of the Rt Revd

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 ...

, Bishop of Osaka and his wife Janet Ovans. As a child of a missionary family stationed in Japan he developed fluency in Japanese from an early age. Foss was later educated at Marlborough College and graduated from Christ's College, Cambridge in 1924. Foss's elder brother

Charles Calveley Foss Brigadier Charles Calveley Foss, (9 March 1885 – 9 April 1953) was an English recipient of the Victoria Cross (VC), the highest and most prestigious award for gallantry in the face of the enemy that can be awarded to British and Commonweal ...

was awarded the

Victoria Cross The Victoria Cross (VC) is the highest and most prestigious award of the British honours system. It is awarded for valour "in the presence of the enemy" to members of the British Armed Forces and may be awarded posthumously. It was previously ...

in the First World War.

Career as a cryptanalyst

In December 1924 he joined the

Government Code and Cipher School 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 ...

. He recalled learning of two models of the Enigma machine in 1926: the large non-reciprocal typing B model, and the small index C model. In 1927

Edward Travis Sir Edward Wilfred Harry Travis (24 September 1888 – 23 April 1956) was a British cryptographer and intelligence officer, becoming the operational head of Bletchley Park during World War II, and later the head of GCHQ. Career Educated loc ...

gave him a small (reciprocal) machine to examine, and he wrote a paper, "The Reciprocal Enigma", on solving the non-plugboard Enigma. The small ModelEnigma was developed by the German services; the standard

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 ...

British Typex machine was also developed from it. In September 1934 Foss and

Oliver Strachey Oliver Strachey CBE (3 November 1874 – 14 May 1960), a British civil servant in the Foreign Office, was a cryptographer from World War I to World War II. Life and work Strachey was a son of Sir Richard Strachey, colonial administrator and ...

broke the Japanese

naval attaché A navy, naval force, or maritime force is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake-borne, riverine, littoral, or ocean-borne combat operations and related functions. It includ ...

cipher. In November 1940 he was the first person to break a day's worth of the German Enigma code, deciphering 8 May 1940 by the method of

Banburismus Banburismus was a cryptanalytic process developed by Alan Turing at Bletchley Park in Britain during the Second World War. It was used by Bletchley Park's Hut 8 to help break German ''Kriegsmarine'' (naval) messages enciphered on Enigma machin ...

. In honour of this feat, 8 May is referred to as "Foss's Day". At

in World War II, Foss headed the Japanese Naval Section (

Hut 7 Hut 7 was a wartime section of the Government Code and Cypher School (GC&CS) at Bletchley Park tasked with the solution of Japanese naval codes such as JN4, JN11, JN40, and JN-25. The hut was headed by Hugh Foss who reported to Frank Birch, the h ...

) from 1942 to 1943. In December 1944 he went to Washington and worked with U.S. Navy cryptographers on Japanese ciphers. A sandal-wearer, he was known as "Lend-lease Jesus".

Gordon Welchman William Gordon Welchman (15 June 1906 – 8 October 1985) was a British mathematician. During World War II, he worked at Britain's secret codebreaking centre, "Station X" at Bletchley Park, where he was one of the most important contributors. ...

was told that Foss was highly esteemed by the Americans, and says that "before the war he was one of the most brilliant of the professional cryptographers of the Government Code and Cypher School". Foss' paper "Reminiscences on Enigma", written in 1949, is included as chapter 3 in ''Action this Day''.

Deviser of Scottish Country Dances

Foss devised many Scottish country dances, including ''Fugal Fergus'', ''John McAlpin'', ''Polharrow Burn'' and ''Wee Cooper O'Fife, The Wee Cooper o'Fife''. He published several volumes of these from his own imprint, ''Glendarroch Press.

Later life

Foss retired from GCHQ in 1953 to live at Glendarroch in St. John's Town of Dalry, Kirkcudbrightshire, Scotland. He died in 1971 and is buried with his wife Alison in Dalry Kirkyard.

Notes and references

Sources

*Dictionary of National Biography * Updated and extended version of ''Action This Day: From Breaking of the Enigma Code to the Birth of the Modern Computer'' Bantam Press 2001 * New edition updated with an ''addendum'' consisting of a 1986 paper written by Welchman that corrects his misapprehensions in the 1982 edition. *https://www.scottish-country-dancing-dictionary.com/hugh-foss.html *https://www.worldcat.org/search?q=au%3AFoss%2C+Hugh.&qt=hot_author {{DEFAULTSORT:Foss, Hugh 1902 births 1971 deaths British cryptographers Pre-computer cryptographers Bletchley Park people Alumni of Christ's College, Cambridge People educated at Marlborough College GCHQ people Foreign Office personnel of World War II