Editing List of cryptographers (section)

==World War I and World War II wartime cryptographers==

* [[Richard J. Hayes]] (1902–1976) Irish code breaker in World War II.
* [[Jean Argles]] (1925–2023), British code breaker in World War II
* [[Arne Beurling]] (1905–1986), Swedish mathematician and cryptographer.
* [[Lambros D. Callimahos]], US, [[NSA]], worked with William F. Friedman, taught NSA cryptanalysts.
* [[Ann Z. Caracristi]], US, [[Signals Intelligence Service|SIS]], solved Japanese Army codes in World War II, later became deputy director of [[National Security Agency]].
* [[Alec Naylor Dakin]], UK, [[Hut 4]], [[Bletchley Park]] during World War II.
* [[Ludomir Danilewicz]], [[Poland]], [[Biuro Szyfrow]], helped to construct the Enigma machine copies to break the ciphers.
* [[Patricia Davies (cryptographer)|Patricia Davies]] (born 1923), British code breaker in World War II
* [[Alastair Denniston]], UK, director of the [[Government Code and Cypher School]] at [[Bletchley Park]] from 1919 to 1942.
* [[Agnes Meyer Driscoll]], US, broke several Japanese ciphers.
* [[Genevieve Grotjan Feinstein]], US, [[Signals Intelligence Service|SIS]], noticed the pattern that led to breaking [[Purple (cipher machine)|Purple]].
* [[Elizebeth Smith Friedman]], US, [[United States Coast Guard|Coast Guard]] and [[United States Department of the Treasury|US Treasury Department]] cryptographer, co-invented modern cryptography.<ref>{{cite magazine|last1=Worrall|first1=Simon|title=This Woman Saved the Americas From the Nazis|url=https://news.nationalgeographic.com/2017/10/elizebeth-friedman-codebreaker-nazi-spy-fagone/|archive-url=https://web.archive.org/web/20171007105852/http://news.nationalgeographic.com/2017/10/elizebeth-friedman-codebreaker-nazi-spy-fagone/|url-status=dead|archive-date=7 October 2017|magazine=National Geographic|access-date=1 April 2018|date=7 October 2017}}</ref>
* [[William F. Friedman]], US, [[Signals Intelligence Service|SIS]], introduced statistical methods into [[cryptography]].
* [[Cecilia Elspeth Giles]], UK, [[Bletchley Park]]
* [[I. J. Good|Jack Good]] UK, [[Government Code and Cypher School]], [[Bletchley Park]] worked with [[Alan Turing]] on the statistical approach to cryptanalysis.
* [[Nigel de Grey]], UK, [[Room 40]], played an important role in the decryption of the [[Zimmermann Telegram]] during World War I.
* [[Dillwyn Knox]], UK, [[Room 40]] and [[Government Code and Cypher School]], broke commercial [[Enigma (machine)|Enigma]] cipher as used by the [[Abwehr]] (German military intelligence).
* [[Solomon Kullback]] US, [[Signals Intelligence Service|SIS]], helped break the Japanese [[Type A Cipher Machine|Red cipher]], later Chief Scientist at the [[National Security Agency]].
* [[Frank W. Lewis]] US, worked with William F. Friedman, puzzle master
* [[Martin and Mitchell Defection|William Hamilton Martin and Bernon F. Mitchell]], U.S. [[National Security Agency]] cryptologists who defected to the Soviet Union in 1960
* [[Leo Marks]] UK, [[Special Operations Executive]] cryptography director, author and playwright.
* [[Donald Michie]] UK, [[Government Code and Cypher School]], [[Bletchley Park]] worked on [[Cryptanalysis of the Lorenz cipher]] and the [[Colossus computer]].
* [[Consuelo Milner]], US, crytopgraher for the [[Naval Applied Science Lab]]
* [[Max Newman]], UK, [[Government Code and Cypher School]], [[Bletchley Park]] headed the section that developed the [[Colossus computer]] for [[Cryptanalysis of the Lorenz cipher]]. 
* [[Georges Painvin]] French, broke the [[ADFGVX cipher]] during the [[First World War]].
* [[Marian Rejewski]], [[Poland]], [[Biuro Szyfrów]], a Polish mathematician and cryptologist who, in 1932, solved the [[Enigma machine]] with plugboard, the main cipher device then in use by Germany. The first to break the cipher in history.
* [[John Joseph Rochefort]] US, made major contributions to the break into [[JN-25]] after the [[attack on Pearl Harbor]].
* [[Leo Rosen]] US, [[Signals Intelligence Service|SIS]], deduced that the [[Type B Cipher Machine|Japanese Purple machine]] was built with stepping switches.
* [[Frank Rowlett]] US, [[Signals Intelligence Service|SIS]], leader of the team that broke [[Purple (cipher machine)|Purple]].
* [[Jerzy Różycki]], [[Poland]], [[Biuro Szyfrów]], helped break German [[Enigma (machine)|Enigma]] ciphers.
* [[Luigi Sacco]], Italy, Italian General and author of the ''Manual of Cryptography''.
* [[Laurance Safford]] US, chief cryptographer for the US Navy for 2 decades+, including World War II.
* [[Abraham Sinkov]] US, [[Signals Intelligence Service|SIS]].
* [[John Tiltman]] UK, Brigadier, [[Room 40]], [[Government Code and Cypher School]], [[Bletchley Park]], [[GCHQ]], [[NSA]]. Extraordinary length and range of cryptographic service
* [[Alan Turing|Alan Mathison Turing]] UK, [[Government Code and Cypher School]], [[Bletchley Park]] where he was chief cryptographer, inventor of the [[Bombe]] that was used in decrypting [[Enigma machine|Enigma]], mathematician, logician, and renowned pioneer of [[Computer Science]]. 
* [[W. T. Tutte|William Thomas Tutte]] UK, [[Government Code and Cypher School]], [[Bletchley Park]], with [[John Tiltman]], broke Lorenz SZ 40/42 encryption machine (codenamed Tunny) leading to the development of the [[Colossus computer]].
* [[Betty Webb (code breaker)]], British codebreaker during World War II
* [[William Stone Weedon]], US, 
* [[Gordon Welchman]] UK, [[Government Code and Cypher School]], [[Bletchley Park]] where he was head of Hut Six (German Army and Air Force [[Enigma machine|Enigma]] [[cipher]]. [[decryption]]), made an important contribution to the design of the [[Bombe]].
* [[Herbert Yardley]] US, [[Black Chamber|MI8 (US)]], author "The American Black Chamber", worked in China as a cryptographer and briefly in Canada.
* [[Henryk Zygalski]], [[Poland]], [[Biuro Szyfrów]], inventor of Zygalski sheets, broke German [[Enigma machine|Enigma]] ciphers pre-1939.
* [[Karl Stein (mathematician)|Karl Stein]] German, Head of the Division IVa (security of own processes) at [[Cipher Department of the High Command of the Wehrmacht]]. Discoverer of [[Stein manifold]].
* [[Gisbert Hasenjaeger]] German, Tester of the Enigma. Discovered new proof of the [[Gödel's completeness theorem|completeness theorem]] of [[Kurt Gödel]] for [[predicate logic]].
* [[Heinrich Scholz]] German, Worked in Division IVa at [[Cipher Department of the High Command of the Wehrmacht|OKW]]. Logician and pen friend of Alan Turning.
* [[Gottfried Köthe]] German, Cryptanalyst at OKW. Mathematician created theory of [[topological vector spaces]].
* [[Ernst Witt]] German, Mathematician at OKW. [[List of things named after Ernst Witt|Mathematical Discoveries Named After Ernst Witt]].
* [[Helmut Grunsky]] German, worked in [[complex analysis]] and [[geometric function theory]]. He introduced [[Grunsky's theorem]] and the [[Grunsky inequalities]].
* [[Georg Hamel]].
* [[Oswald Teichmüller]] German, temporarily employed at OKW as cryptanalyst. Introduced [[quasiconformal mapping]]s and [[differential geometry|differential geometric]] methods into [[complex analysis]]. Described by [[Friedrich L. Bauer]] as an extreme Nazi and a true genius. 
* [[Hans Rohrbach]] German, Mathematician at AA/Pers Z, the German department of state, civilian diplomatic cryptological agency.
* [[Wolfgang Franz (mathematician)|Wolfgang Franz]] German, Mathematician who worked at OKW. Later significant discoveries in [[Topology]]. 
* [[Werner Weber (mathematician)|Werner Weber]] German, Mathematician at OKW.
* [[Georg Aumann]] German, Mathematician at OKW. His doctoral student was [[Friedrich L. Bauer]].
* [[Otto Leiberich]] German, Mathematician who worked as a linguist at the [[Cipher Department of the High Command of the Wehrmacht]].
* [[Alexander Aigner]] German, Mathematician who worked at OKW.
* [[Erich Hüttenhain]] German, Chief cryptanalyst of and led Chi IV (section 4) of the [[Cipher Department of the High Command of the Wehrmacht]]. A German mathematician and cryptanalyst who tested a number of German cipher machines and found them to be breakable.  
* [[Wilhelm Fenner]] German, Chief Cryptologist and Director of [[Cipher Department of the High Command of the Wehrmacht]]. 
* [[Walther Fricke]] German, Worked alongside Dr Erich Hüttenhain at [[Cipher Department of the High Command of the Wehrmacht]]. Mathematician, logician, cryptanalyst and linguist.
* [[Fritz Menzer]] German. Inventor of SG39 and SG41.