Title: History of cryptography
Content:  Alan Turing (the conceptual founder of modern computing) – made substantial breakthroughs in the scale and technology of Enigma decryption. German code breaking in World War II also had some success, most importantly by breaking the Naval Cipher No. 3. This enabled them to track and sink Atlantic convoys. It was only Ultra intelligence that finally persuaded the admiralty to change their codes in June 1943. This is surprising given the success of the British Room 40 code breakers in the previous world war. At the end of the War, on 19 April 1945, Britain's highest level civilian and military officials were told that they could never reveal that the German Enigma cipher had been broken because it would give the 
Title: World War II cryptography
Content:  Cryptography was used extensively during World War II because of the importance of radio communication and the ease of radio interception. The nations involved fielded a plethora of code and cipher systems, many of the latter using rotor machines. As a result, the theoretical and practical aspects of cryptanalysis, or codebreaking, were much advanced. Possibly the most important codebreaking event of the war was the successful decryption by the Allies of the German "Enigma" Cipher. The first break into Enigma was accomplished by 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 
Title: Ultra
Content:  from the Poles, in the nick of time, the details both of the German military Enigma machine, and of the operating procedures that were in use." - Gordon Welchman At Bletchley Park, some of the key people responsible for success against Enigma included mathematicians Alan Turing and Hugh Alexander and, at the British Tabulating Machine Company, chief engineer Harold Keen. After the war, interrogation of German cryptographic personnel led to the conclusion that German cryptanalysts understood that cryptanalytic attacks against Enigma were possible but were thought to require impracticable amounts of effort and investment. The Poles' early start at breaking Enigma and the continuity of their success gave the Allies an advantage when World War II began.
Title: Alan Turing
Content:  During the Second World War, Turing was a leading participant in the breaking of German ciphers at Bletchley Park. The historian and wartime codebreaker Asa Briggs has said, "You needed exceptional talent, you needed genius at Bletchley and Turing's was that genius." From September 1938, Turing worked part-time with the Government Code and Cypher School (GC&CS), the British codebreaking organisation. He concentrated on cryptanalysis of the Enigma cipher machine used by Nazi Germany, together with Dilly Knox, a senior GC&CS codebreaker. Soon after the July 1939 meeting near Warsaw at which the Polish Cipher Bureau gave the British and French details of the wiring of Enigma machine's rotors and 
Title: Breaking the Code (film)
Content:  The story focuses on the life of the English mathematician Alan Turing, who helped decode the Enigma code, used by the Germans to send secret orders to their U-boats in World War II. He also was one of the key contributors to the development of the digital computer. Turing was also a homosexual in Britain at a time when it was illegal.
Title: Cryptanalysis of the Enigma
Content:  was these poor procedures that allowed the Enigma machines to be reverse-engineered and the ciphers to be read. The German plugboard-equipped Enigma became Nazi Germany's principal crypto-system. In December 1932 it was "broken" by mathematician Marian Rejewski at the Polish General Staff's Cipher Bureau, using mathematical permutation group theory combined with French-supplied intelligence material obtained from a German spy. By 1938 Rejewski had invented a device, the cryptologic bomb, and Henryk Zygalski had devised his sheets, to make the cipher-breaking more efficient. Five weeks before the outbreak of World War II, in late July 1939, at a conference just south 
Title: Marian Rejewski
Content:  Denniston, veteran cryptologist Alfred Dillwyn Knox, and Commander Humphrey Sandwith, head of the section that had developed and controlled the Royal Navy's intercept and direction-finding stations. The Polish hosts included Cipher Bureau chief Gwido Langer, the Bureau's German-Section chief Maksymilian Ciężki, the Bureau's General-Staff-Intelligence supervisor Stefan Mayer, and the three cryptologists Rejewski, Różycki and Zygalski. The Poles' gift of Enigma decryption to their Western allies, five weeks before the outbreak of World War II, came not a moment too soon. Knowledge that the cipher was crackable was a morale boost to Allied cryptologists. The British were able to manufacture at least two complete sets of perforated sheets—they sent one to PC Bruno, outside Paris, in mid-December 1939—and 
Title: Peter Twinn
Content:  obvious thing to do that nobody considered it worth trying. In early 1940 Twinn made the first break into Enigma. This could have been done much earlier if only they had tried the alphabetical system detailed in the patent application. The ability to read German encoded military messages was of inestimable help to the Allies in winning the war. It was achieved largely because of the efforts of Twinn, Knox, Alan Turing (who later became the father of artificial intelligence) and others at Bletchley Park. Turing, a brilliant mathematician, developed a machine called the “bombe”, which speeded up the deciphering process by trial and error — a crucial development for the codebreakers.
Title: Jimmy Launders
Content:  started to make an abnormally loud, rhythmic noise that could be easily detected by any anti-submarine warfare equipment in the area. Wofram decided to return to Bergen to repair the problem. Neither he nor anyone in the Nazi high command knew that the Enigma code, Germany's top-secret naval encryption system, had been broken by British mathematician Alan Turing and his cryptanalytics team at Bletchley Park. All naval communications to and from the U-boat fleet were being read by the Allies, and they knew of Operation Caesar. Wishing to deny the Japanese any advantage that might extend the war in the Pacific, Royal Navy Submarine Command dispatched Venturer to intercept and destroy U-864. Launders 
Title: Operation Overlord
Content:  on Axis troop movements and on construction techniques used by the Germans for bunkers and other defensive installations. Many German radio messages were encoded using the Enigma machine and other enciphering techniques and the codes were changed frequently. A team of code breakers stationed at Bletchley Park worked to break codes as quickly as possible to provide advance information on German plans and troop movements. British military intelligence code-named this information Ultra intelligence as it could only be provided to the top level of commanders. The Enigma code used by Field Marshal Gerd von Rundstedt, Oberbefehlshaber West (Supreme Commander West; OB West), commander of the Western Front, was broken by the end of March. German intelligence changed the Enigma codes right after the Allied landings of 6 June but by 17 June the Allies were again consistently able to read them.

Question: who cracked the enigma code in world war 2?
Answer: Turing.