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

Bletchley Park Bletchley Park is an English country house and Bletchley Park estate, estate in Bletchley, Milton Keynes (Buckinghamshire), that became the principal centre of Allies of World War II, Allied World War II cryptography, code-breaking during the S ...

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 Kobe ( ; , ), officially , is the capital city of Hyōgo Prefecture, Japan. With a population of around 1.5 million, Kobe is Japan's List of Japanese cities by population, seventh-largest city and the third-largest port city after Port of Toky ...

, Japan, one of five children of the Rt Revd Hugh Foss, 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 Marlborough College is a Public school (United Kingdom), public school (English private boarding school) for pupils aged 13 to 18 in Marlborough, Wiltshire, England. It was founded as Marlborough School in 1843 by the Dean of Manchester, George ...

and graduated from

Christ's College, Cambridge Christ's College is a Colleges of the University of Cambridge, constituent college of the University of Cambridge, England. The college includes the Master, the Fellows of the College, and about 450 undergraduate and 250 graduate students. The c ...

in 1924. Foss's elder brother Charles Calveley Foss was awarded the

Victoria Cross The Victoria Cross (VC) is the highest and most prestigious decoration of the Orders, decorations, and medals of the United Kingdom, British decorations system. It is awarded for valour "in the presence of the enemy" to members of the British ...

in the First World War.

Career as a cryptanalyst

In December 1924 he joined the

Government Code and Cypher School The Government Code and Cypher School (GC&CS) was a British signals intelligence agency set up in 1919. During the First World War, the British Army and Royal Navy had separate signals intelligence agencies, MI1b and NID25 (initially known as R ...

. He recalled learning of two models of the

Enigma machine The Enigma machine is a cipher device developed and used in the early- to mid-20th century to protect commercial, diplomatic, and military communication. It was employed extensively by Nazi Germany during World War II, in all branches of the W ...

in 1926: the large non-reciprocal typing B model, and the small index C model. In 1927 Edward Travis 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 (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

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 J ...

broke the Japanese naval attaché 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 Cryptanalysis, cryptanalytic process developed by Alan Turing at Bletchley Park in United Kingdom, Britain during the Second World War. It was used by Bletchley Park's Hut 8 to help break German ''Kriegsmarine'' (naval) message ...

. 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) 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 OBE (15 June 1906 – 8 October 1985) was an English mathematician. During World War II, he worked at Britain's secret decryption centre at Bletchley Park, where he was one of the most important contributors. In 1948, a ...

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 dance Scottish country dance (SCD) is the distinctively Scottish form of country dance, itself a form of social dance involving groups of couples of dancers tracing progressive patterns. A dance consists of a sequence of figures. These dances are ...

s, including '' Fugal Fergus'', '' John McAlpin'', '' Polharrow Burn'' and '' 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 The ''Dictionary of National Biography'' (''DNB'') is a standard work of reference on notable figures from British history, published since 1885. The updated ''Oxford Dictionary of National Biography'' (''ODNB'') was published on 23 September ...

* 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. {{DEFAULTSORT:Foss, Hugh 1902 births 1971 deaths British cryptographers 20th-century cryptographers Bletchley Park people Alumni of Christ's College, Cambridge People educated at Marlborough College GCHQ people Foreign Office personnel of World War II