Gordon Welchman
Encyclopedia
Gordon Welchman (15 June 1906 – 8 October 1985) was a British
-American
mathematician
, university professor
, World War II
codebreaker
at Bletchley Park
, and author
.
from 1925 to 1928. In 1929 he became a Research Fellow in mathematics at Sidney Sussex College, Cambridge
, a Fellow in 1932, and later Dean of the College.
Just before World War II, Welchman was invited by Commander Alastair Denniston
to join the Government Code & Cypher School at Bletchley Park
, in case war broke out. He was one of four early recruits to Bletchley (the others being Alan Turing
, Hugh Alexander
, and Stuart Milner-Barry
), who all made significant contributions at Bletchley, and who became known as 'The Wicked Uncles'. They were also the four signatories to an influential letter, delivered personally to Winston Churchill
in October 1941, asking for more resources for the code-breaking work at Bletchley Park. Churchill responded with one of his 'Action This Day' stickers.
Welchman envisaged an enhancement to Alan Turing
's improved design of the Polish electromechanical Enigma-cipher
-breaking machine, the bombe
. Welchman's enhancement, the 'diagonal board', rendered the device substantially more efficient in the attack on ciphers generated by the German Enigma machine
. Bombes became the primary mechanical aid in breaking Enigma ciphers during the war, by speeding up the search for current settings being used with the Enigma machines; these were changed often, initially at least once per day.
Welchman was head of Hut Six, the section at Bletchley Park responsible for breaking German Army and Air Force Enigma ciphers. In 1943 he became Assistant Director in charge of mechanisation, and also had responsibility for cryptographic liaison with the USA.
, working on secure communications systems for the US military. He retired in 1971, but was still retained as a consultant. In 1982, McGraw-Hill published his book The Hut Six Story in the USA, the British version being published by Allen Lane. The book was frowned on by the National Security Agency
, and its author lost his security clearance (and therefore his consultancy with MITRE), and was forbidden to discuss his book or his wartime work with the media. The offending book was, however, not banned. His final conclusions and corrections to the story of wartime codebreaking were contained in a paper published posthumously in 1986 (Welchman having died in 1985) 'From Polish Bomba to British Bombe: the birth of Ultra' in Intelligence & National Security, Vol 1, No l. The entire paper was included in the revised edition of The Hut Six Story published in 1997 by M & M Baldwin.
He was survived by three children, two stepchildren, and eight grandchildren.
British people
The British are citizens of the United Kingdom, of the Isle of Man, any of the Channel Islands, or of any of the British overseas territories, and their descendants...
-American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
, university professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
, World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
codebreaker
Codebreaker
Codebreaker may refer to:*A person who performs cryptanalysis*The Codebreakers, a 1967 book on history of cryptography by David Kahn*Codebreaker , a 1981 puzzle-based computer game, originally released for the Atari 2600...
at Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
, and author
Author
An author is broadly defined as "the person who originates or gives existence to anything" and that authorship determines responsibility for what is created. Narrowly defined, an author is the originator of any written work.-Legal significance:...
.
Education and early career
Gordon Welchman studied Mathematics as a scholar at Trinity College, CambridgeTrinity College, Cambridge
Trinity College is a constituent college of the University of Cambridge. Trinity has more members than any other college in Cambridge or Oxford, with around 700 undergraduates, 430 graduates, and over 170 Fellows...
from 1925 to 1928. In 1929 he became a Research Fellow in mathematics at Sidney Sussex College, Cambridge
Sidney Sussex College, Cambridge
Sidney Sussex College is a constituent college of the University of Cambridge in England.The college was founded in 1596 and named after its foundress, Frances Sidney, Countess of Sussex. It was from its inception an avowedly Puritan foundation: some good and godlie moniment for the mainteynance...
, a Fellow in 1932, and later Dean of the College.
At Bletchley Park
Alastair Denniston
Commander Alexander Guthrie Denniston CMG CBE RNVR was a British codebreaker in Room 40 and first head of the Government Code and Cypher School and field hockey player...
to join the Government Code & Cypher School at Bletchley Park
Bletchley Park
Bletchley Park is an estate located in the town of Bletchley, in Buckinghamshire, England, which currently houses the National Museum of Computing...
, in case war broke out. He was one of four early recruits to Bletchley (the others being Alan Turing
Alan Turing
Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which played a...
, Hugh Alexander
Conel Hugh O'Donel Alexander
Conel Hugh O'Donel Alexander, CMG, CBE was an Irish-born British cryptanalyst, chess player, and chess writer. He worked on the German Enigma machine at Bletchley Park during World War II, and was later the head of the cryptanalysis division at GCHQ for over 20 years...
, and Stuart Milner-Barry
Stuart Milner-Barry
Sir Stuart Milner-Barry KCVO, CB, OBE was a British chess player, chess writer, World War II codebreaker and civil servant. He represented England in chess both before and after World War II...
), who all made significant contributions at Bletchley, and who became known as 'The Wicked Uncles'. They were also the four signatories to an influential letter, delivered personally to Winston Churchill
Winston Churchill
Sir Winston Leonard Spencer-Churchill, was a predominantly Conservative British politician and statesman known for his leadership of the United Kingdom during the Second World War. He is widely regarded as one of the greatest wartime leaders of the century and served as Prime Minister twice...
in October 1941, asking for more resources for the code-breaking work at Bletchley Park. Churchill responded with one of his 'Action This Day' stickers.
Welchman envisaged an enhancement to Alan Turing
Alan Turing
Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which played a...
's improved design of the Polish electromechanical Enigma-cipher
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
-breaking machine, the bombe
Bombe
The bombe was an electromechanical device used by British cryptologists to help decipher German Enigma-machine-encrypted signals during World War II...
. Welchman's enhancement, the 'diagonal board', rendered the device substantially more efficient in the attack on ciphers generated by the German Enigma machine
Enigma machine
An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by German engineer Arthur Scherbius at the end of World War I...
. Bombes became the primary mechanical aid in breaking Enigma ciphers during the war, by speeding up the search for current settings being used with the Enigma machines; these were changed often, initially at least once per day.
Welchman was head of Hut Six, the section at Bletchley Park responsible for breaking German Army and Air Force Enigma ciphers. In 1943 he became Assistant Director in charge of mechanisation, and also had responsibility for cryptographic liaison with the USA.
After World War II
Welchman moved to the United States in 1948, and taught the first computer course at MIT. He followed this by employment with Remington Rand and Ferranti. He became a naturalised American citizen in 1962. In that year, he joined the MITRE CorporationMITRE
The Mitre Corporation is a not-for-profit organization based in Bedford, Massachusetts and McLean, Virginia...
, working on secure communications systems for the US military. He retired in 1971, but was still retained as a consultant. In 1982, McGraw-Hill published his book The Hut Six Story in the USA, the British version being published by Allen Lane. The book was frowned on by the National Security Agency
National Security Agency
The National Security Agency/Central Security Service is a cryptologic intelligence agency of the United States Department of Defense responsible for the collection and analysis of foreign communications and foreign signals intelligence, as well as protecting U.S...
, and its author lost his security clearance (and therefore his consultancy with MITRE), and was forbidden to discuss his book or his wartime work with the media. The offending book was, however, not banned. His final conclusions and corrections to the story of wartime codebreaking were contained in a paper published posthumously in 1986 (Welchman having died in 1985) 'From Polish Bomba to British Bombe: the birth of Ultra' in Intelligence & National Security, Vol 1, No l. The entire paper was included in the revised edition of The Hut Six Story published in 1997 by M & M Baldwin.
He was survived by three children, two stepchildren, and eight grandchildren.