John Herivel, Date of Birth, Place of Birth, Date of Death

John Herivel

British science historian, World War II codebreaker at Bletchley Park

Date of Birth: 29-Aug-1918

Place of Birth: Belfast, Northern Ireland

Date of Death: 18-Jan-2011

Profession: mathematician, historian, biographer

Nationality: United Kingdom

Zodiac Sign: Virgo

John William Jamieson Herivel (29 August 1918 – 18 January 2011) was a British science historian and former World War II codebreaker at Bletchley Park.As a codebreaker concerned with Cryptanalysis of the Enigma, Herivel is remembered chiefly for the discovery of what was soon dubbed the Herivel tip or Herivelismus.
Herivelismus consisted of the idea, the Herivel tip and the method of establishing whether it applied using the Herivel square.
It was based on Herivel's insight into the habits of German operators of the Enigma cipher machine that allowed Bletchley Park to easily deduce part of the daily key.
For a brief but critical period after May 1940, the Herivel tip in conjunction with "cillies" (another class of operator error) was the main technique used to solve Enigma. After the war, Herivel became an academic, studying the history and philosophy of science at Queen's University Belfast, particularly Isaac Newton, Joseph Fourier, Christiaan Huygens.
In retirement, he wrote an autobiographical account of his work at Bletchley Park entitled Herivelismus and the German Military Enigma.