Margaret Alice Rock (7 July 1903 – 26 August 1983) was one of the women mathematicians who worked in Bletchley Park during World War II.
Her father died when the armed merchant cruiser HMS Laurentic sank off the coast of Ireland having struck two mines laid by a German U-boat.
[3] Margaret quit her old job, wanting a career in a time when the woman's role was primarily to be the wife and stay-at-home mother.
[3] She worked for Admiral Sir Hugh Sinclair, who was the head of the Government Code and Cypher School and Secret Intelligence Service.
[10] By her hard work, Rock was ranked one of the better workers on the Enigma machine project, and was promoted to seniority and a higher salary.
On 8 December 1941, an Abwehr Enigma message was decoded and read by the team in Bletchley Park by the use of a manual technique called "rodding" that was identified by Knox.
[3] Even late in her life, when stories about Bletchley Park and codebreaking were making the news, she would not comment about her contribution to the Colossus.