Editing World War II cryptography

{{Short description|Military code use and breaking during the Second World War}}
'''Cryptography was used extensively during World War II''' because of the importance of radio communication and the ease of [[Listening station|radio interception]]. The nations involved fielded a plethora of [[code (cryptography)|code]] and [[cipher]] systems, many of the latter using [[rotor machine]]s. As a result, the theoretical and practical aspects of ''[[cryptanalysis]]'', or ''codebreaking'', were much advanced.

Possibly the most important codebreaking event of [[World War II|the war]] was the successful decryption by the Allies of the German [[Cryptanalysis of the Enigma|"Enigma" Cipher]].  The first [[cryptanalysis|break]] into Enigma was accomplished by [[Cipher Bureau (Poland)|Polish Cipher Bureau]] around 1932; the techniques and insights used were passed to the French and British Allies just before the outbreak of the war in 1939. They were substantially improved by British efforts at [[Bletchley Park]] during the war. Decryption of the [[Cryptanalysis of the Enigma|Enigma Cipher]] allowed the Allies to read important parts of German radio traffic on important networks and was an invaluable source of [[military intelligence]] throughout the war. Intelligence from this source and other high level sources, such as  [[Cryptanalysis of the Lorenz cipher]], was eventually called [[Ultra (cryptography)|Ultra]].<ref>{{Cite book|url=https://books.google.com/books?id=uccLlgJDk4gC&q=World+War+II+cryptography|title=Battle of Wits: The Complete Story of Codebreaking in World War II|last=Budiansky|first=Stephen|date=2000|publisher=Simon and Schuster|isbn=9780684859323|language=en}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=j1MC2d2LPAcC&q=World+War+II+codebreaking|title=Codebreakers: The Inside Story of Bletchley Park|last1=Hinsley|first1=F. H.|last2=Stripp|first2=Alan|date=2001|publisher=Oxford University Press|isbn=9780192801326|language=en}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=99oqAwAAQBAJ&q=World+War+II+codebreaking|title=Codebreakers' Victory: How the Allied Cryptographers Won World War II|last=Haufler|first=Hervie|date=2014|publisher=Open Road Media|isbn=9781497622562|language=en}}</ref>

A similar break into the most secure Japanese diplomatic cipher, designated [[Type B Cipher Machine|Purple]] by the US Army Signals Intelligence Service, started before the US entered the war. Product from this source was called [[Magic (cryptography)|Magic]].

On the other side, [[German code breaking in World War II]] achieved some notable successes cracking British naval and other ciphers.

==Australia==
* [[Central Bureau]]
* [[FRUMEL]]: [[Fleet Radio Unit]], Melbourne
* [[Secret Intelligence Australia]]

==Finland==
* [[Finnish Defence Intelligence Agency#Signals intelligence|Finnish Defence Intelligence Agency]]

==France==
* [[PC Bruno]]
* [[Hans-Thilo Schmidt]]

==Germany==
* [[Enigma machine]]
* [[Fish (cryptography)]] British codename for German teleprinter ciphers
** [[Lorenz cipher]] a Fish cipher codenamed ''Tunny'' by the British
** [[Siemens and Halske T52]] Geheimfernschreiber, a Fish cipher codenamed ''Sturgeon'' by the British
* [[Short Weather Cipher]]
* [[B-Dienst]]
* [[Reservehandverfahren]]
* [[Cipher Department of the High Command of the Wehrmacht|OKW/CHI]]
* [[Gisbert Hasenjaeger]]

==Italy==
* [[C-36 (cipher machine)|Hagelin machine]]
* [[Enigma machine]]

==Japan==
* [[Japanese army and diplomatic codes]] 
* [[Japanese naval codes]]
* [[PURPLE]]
* [[JN-25]]

==Poland==
* [[Cryptanalysis of the Enigma]]
* [[Biuro Szyfrów]] (Cipher Bureau)
* [[Marian Rejewski]]
* [[Jerzy Różycki]]
* [[Henryk Zygalski]]
* [[Bomba (cryptography)|bomba]]
* [[Lacida| Lacida Machine]]

== Soviet Union ==
* 5th Department of [[NKVD]] (1941-1943), 5th Department of NKGB (1943-1945)
** [[Lieutenant general]] Ivan Shevelyov, the head of the department
* 8th Department of [[General Staff of the Armed Forces of the Russian Federation|Red Army General Staff]]
** [[Lieutenant general]] Piotr Belyusov, the head of the department

==Sweden==
* [[Arne Beurling]]

==United Kingdom==
* [[Bletchley Park]]
* [[Cryptanalysis of the Enigma]]
* [[Cryptanalysis of the Lorenz cipher]]
* [[Far East Combined Bureau]] (FECB) 
* [[Naval Intelligence Division (United Kingdom)|Naval Intelligence Division]] (NID)
* [[Wireless Experimental Centre]] (WEC) 
* [[Bombe]] 
* [[Colossus computer]]
* [[Typex]]
* [[Syko Cipher Device|SYKO]]
* [[Ultra (cryptography)|Ultra]]
* [[Alan Turing]]
* [[W. T. Tutte]]
* [[John Tiltman]]
* [[Max Newman]]
* [[Tommy Flowers]]
* [[I. J. Good]]
* [[John Herivel]]
* [[Leo Marks]]
* [[Gordon Welchman]]
* [[Poem code]]

==United States==
* [[Magic (cryptography)]]
* [[Signals Intelligence Service]] US Army, see also [[Arlington Hall]]
* [[OP-20-G]] US Navy Signals Intelligence group
* [[Elizebeth Smith Friedman]]
* [[William Friedman]]
* [[Frank Rowlett]]
* [[Abraham Sinkov]]
* [[Genevieve Grotjan Feinstein]]
* [[Leo Rosen]]
* [[Joseph Rochefort]], leader of the effort to crack Japanese Naval codes
* [[Joseph Mauborgne]]
* [[Agnes Meyer Driscoll]]
* [[SIGABA]] cipher machine
* [[SIGSALY]] voice encryption
* [[SIGTOT]] one-time tape system
* [[M-209]] cipher machine
* [[Station HYPO]] cryptanalysis group
* [[Station CAST]] cryptanalysis group
* [[Station NEGAT]]

==See also==
*[[Cryptography]]
*[[History of cryptography]]
*[[World War I cryptography]]

<!-- intelligence derived from codebreaking-->
* [[Ultra (cryptography)]]
* [[Magic (cryptography)]]

<!-- cryptanalysis techniques in WWII -->
* [[Cryptanalysis of the Enigma]]
* [[Bombe]]

<!-- codes and ciphers used in WWII -->
* [[Enigma (machine)]]
* [[SIGABA]]
* [[TypeX]]
* [[Lorenz cipher]]
* [[Geheimfernschreiber]]
* [[Codetalkers]]
* [[PURPLE]]
* [[SIGSALY]]
* [[JN-25]]

<!-- cryptanalytic organisations -->
* [[Bletchley Park]]
* [[Biuro Szyfrów]]
* [[PC Bruno]]
* [[Signals Intelligence Service|SIS]] US Army, later moved to Arlington Hall
* [[OP-20-G]] US Navy

<!-- codebreakers -->
<!--poland-->
* [[Marian Rejewski]]
* [[Jerzy Różycki]]
* [[Henryk Zygalski]]

<!-- UK -->
* [[Alan Turing]]
* [[W. T. Tutte]]
* [[John Tiltman]]
* [[Max Newman]]
* [[Tommy Flowers]]
* [[I. J. Good]]

<!-- US -->
* [[William Friedman]]
* [[Frank Rowlett]]
* [[Abraham Sinkov]]
* [[Joseph Rochefort]]
* [[Agnes Meyer Driscoll]]

<!-- misc -->
* [[Hans-Thilo Schmidt]]

==References==
{{Reflist}}

{{World War II}}
{{Authority control}}

{{DEFAULTSORT:World War Ii Cryptography}}
[[Category:History of cryptography]]
[[Category:Signals intelligence of World War II|Cryptography]]