|Born||Joan Elisabeth Lowther Clarke
5 May 1917
|Died||4 September 1996(aged 79)|
|Alma mater||Newnham College, Cambridge|
|Known for||Codebreaking at Bletchley Park|
Work at Bletchley Park
In June 1940 she was recruited by the Government Code and Cypher School (GC&CS) to work at Bletchley Park. She worked in the section known as Hut 8, and quickly became one of the practitioners of Banburismus, a cryptanalytic process developed by Alan Turing which reduced the need for bombes. Hugh Alexander, head of Hut 8 from 1943 to 1944, described her as "one of the best Banburists in the section". She became deputy head of Hut 8 in 1944.
Relationship with Alan Turing
In 1941, fellow code-breaker Alan Turing proposed marriage to Clarke, but their engagement was short-lived. After admitting his homosexuality to Clarke, who was reportedly "unfazed" by the revelation, Turing decided that he could not go through with the marriage.
After the war
At the end of World War II, GC&CS became GCHQ. At GCHQ, Clarke met John "Jock" Murray and they married in 1952. Shortly after, the couple left GCHQ due to Jock's ill health, and moved to Crail, Fife. There they researched history and especially Scottish coinage of the 16th and 17th centuries. They returned to GCHQ in 1962, Jock retiring in 1971 and Joan in 1977.
In 1986, following Jock's death, Joan moved to Headington, near Oxford, where she continued her research into coinage. In the 1980s, she also assisted historians studying war-time code breaking at Bletchley Park. However, because of continuing secrecy amongst cryptanalysts, the full extent of her accomplishments remains unknown.
- Erskine, Ralph. "Murray [Clarke], Joan Elisabeth Lowther (1917–1996)". Oxford Dictionary of National Biography, Oxford University Press. Retrieved 27 October 2013.
- Burman, Annie. "Gendering decryption - decrypting gender The gender discourse of labour at Bletchley Park 1939-1945". Retrieved 27 October 2013.
- "Women Codebreakers". Retrieved 3 November 2013.
- Leavitt, David (2007). The man who knew too much: Alan Turing and the invention of the computer. Phoenix. pp. 176–178. ISBN 978-0-7538-2200-5.
- Lord, Lynsey Ann (2008). "Joan Elisabeth Lowther Clarke Murray". honours project. University of St Andrews. Retrieved 5 November 2013.
- Stewart, Ian (1986). "Obituary : Lieutenant-Colonel J.K.R. Murray". British Numismatic Journal (British Numismatic Society) 56: 201–203. Retrieved 5 November 2013.