Ultra (cryptography)

808:. Each SLU included intelligence, communications, and cryptographic elements. It was headed by a British Army or RAF officer, usually a major, known as "Special Liaison Officer". The main function of the liaison officer or his deputy was to pass Ultra intelligence bulletins to the commander of the command he was attached to, or to other indoctrinated staff officers. In order to safeguard Ultra, special precautions were taken. The standard procedure was for the liaison officer to present the intelligence summary to the recipient, stay with him while he studied it, then take it back and destroy it. 1474: 728:. Detailed reports by the Japanese ambassador to Germany were encrypted on the Purple machine. His reports included reviews of German assessments of the military situation, reviews of strategy and intentions, reports on direct inspections by the ambassador (in one case, of Normandy beach defences), and reports of long interviews with Hitler. The Japanese are said to have obtained an Enigma machine in 1937, although it is debated whether they were given it by the Germans or bought a commercial version, which, apart from the plugboard and internal wiring, was the German 500: 1456:, and a British destroyer promptly showed up. The U-boats escaped and reported what had happened. Dönitz immediately asked for a review of Enigma's security. The analysis suggested that the signals problem, if there was one, was not due to the Enigma itself. Dönitz had the settings book changed anyway, blacking out Bletchley Park for a period. However, the evidence was never enough to truly convince him that Naval Enigma was being read by the Allies. The more so, since 255: 221: 2009:, Anthony Cave Brown rendered this as "Churchill told King George VI in Menzies's presence that 'it was thanks to Ultra that we won the war.'" (p. 671) He sourced this (p. 812n) to the same page of the Bertrand book. Subsequent English-language publications have picked up and repeated Brown's formulation, but the quote related by Menzies and Bertrand was longer and Churchill did not use the term 'Ultra' to the King, who may not have been familiar with it. 1565:. His book reports that several times during the war they undertook detailed investigations to see whether their operations were being compromised by broken Enigma ciphers. These investigations were spurred because the Germans had broken the British naval code and found the information useful. Their investigations were negative, and the conclusion was that their defeat "was due firstly to outstanding developments in enemy radar..." The great advance was 581:, using a combination of brilliant mathematics, the services of a spy in the German office responsible for administering encrypted communications, and good luck. The Poles read Enigma to the outbreak of World War II and beyond, in France. At the turn of 1939, the Germans made the systems ten times more complex, which required a tenfold increase in Polish decryption equipment, which they could not meet. On 25 July 1939, the Polish Cipher Bureau handed 1489:, about three quarters of the work force. Before the attack on Pearl Harbor, the US Navy sent letters to top women's colleges seeking introductions to their best seniors; the Army soon followed suit. By the end of the war, some 7000 workers in the Army Signal Intelligence service, out of a total 10,500, were female. By contrast, the Germans and Japanese had strong ideological objections to women engaging in war work. The Nazis even created a 508: 238: 31: 1765:(the Government Communications Headquarters), who identifies himself only as "Tony" but seems to speak authoritatively, says that Ultra was a "major force multiplier. It was the first time that quantities of real-time intelligence became available to the British military." He further states that it is only in 2012 that Alan Turing's last two papers on Enigma decryption have been released to Britain's 752: 620:. 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. 1719:

Commander Denniston went clandestinely to a secluded Polish castle on the eve of the war. Dilly Knox later solved its keying, exposing all Abwehr signals encoded by this system." "In 1941 he brilliant cryptologist Dillwyn Knox, working at the Government Code & Cypher School at the Bletchley centre of British code-cracking, solved the keying of the Abwehr's Enigma machine."

427:, Bletchley Park veteran and official historian of British Intelligence in World War II, made a similar assessment of Ultra, saying that while the Allies would have won the war without it, "the war would have been something like two years longer, perhaps three years longer, possibly four years longer than it was." However, Hinsley and others have emphasized the difficulties of 937:. This was an extremely well informed, responsive ring that was able to get information "directly from German General Staff Headquarters"—often on specific request. It has been alleged that "Lucy" was in major part a conduit for the British to feed Ultra intelligence to the Soviets in a way that made it appear to have come from highly placed espionage rather than from 1178:. This situation persisted until December 1942, although other German naval Enigma messages were still being deciphered, such as those of the U-boat training command at Kiel. From December 1942 to the end of the war, Ultra allowed Allied convoys to evade U-boat patrol lines, and guided Allied anti-submarine forces to the location of U-boats at sea. 1853:(Government Communication Headquarters) and the United States' NSA. "Let no one be fooled", Winterbotham admonishes in chapter 3, "by the spate of television films and propaganda which has made the war seem like some great triumphant epic. It was, in fact, a very narrow shave, and the reader may like to ponder whether we might have won Ultra." 1105:. F. W. Winterbotham claimed that Churchill had advance warning, but intentionally did nothing about the raid, to safeguard Ultra. This claim has been comprehensively refuted by R. V. Jones, Sir David Hunt, Ralph Bennett and Peter Calvocoressi. Ultra warned of a raid but did not reveal the target. Churchill, who had been 666:

Lorenz-enciphered messages contributed significantly, and perhaps decisively, to the defeat of Nazi Germany. Nevertheless, the Tunny story has become much less well known among the public than the Enigma one. At Bletchley Park, some of the key people responsible for success in the Tunny effort included mathematicians

566:(German military intelligence) used a four-rotor machine without a plugboard and Naval Enigma used different key management from that of the army or air force, making its traffic far more difficult to cryptanalyse; each variant required different cryptanalytic treatment. The commercial versions were not as secure and 2001:« C'est grâce à l'Arme Secrète du général Menziès, mise en œuvre sur tous les Fronts, que nous avons gagné la Guerre! » " This can be translated as: "Not to mention this historic meeting, after the war, in which Sir Winston Churchill, presenting to H.M. George VI the Chief of the I.S., stated these words, 1606:

mentions Hinsley's estimate of at least two years, and concludes that "It might be more accurate to say that Ultra helped shorten the war by three months – the interval between the actual end of the war in Europe and the time the United States would have been able to drop an atomic bomb on Hamburg or

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I am very well aware of the immense amount of work and effort which has been involved in the production of the material with which you supplied us. I fully realize also the numerous setbacks and difficulties with which you have had to contend and how you have always, by your supreme efforts, overcome

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After encryption systems were "broken", there was a large volume of cryptologic work needed to recover daily key settings and keep up with changes in enemy security procedures, plus the more mundane work of processing, translating, indexing, analyzing and distributing tens of thousands of intercepted

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to North Africa with essential supplies at a critical moment in the North African fighting. There was no time to have the ships properly spotted beforehand. The decision to attack solely on Ultra intelligence went directly to Churchill. The ships were all sunk by an attack "out of the blue", arousing

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argues that, as Harris was not cleared for access to Ultra, he was given some information gleaned from Enigma but not the information's source. This affected his attitude about post-D-Day directives to target oil installations, since he did not know that senior Allied commanders were using high-level

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The distribution of Ultra information to Allied commanders and units in the field involved considerable risk of discovery by the Germans, and great care was taken to control both the information and knowledge of how it was obtained. Liaison officers were appointed for each field command to manage and

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machines, which were the first digital programme-controlled electronic computers. In many respects the Tunny work was more difficult than for the Enigma, since the British codebreakers had no knowledge of the machine producing it and no head-start such as that the Poles had given them against Enigma.

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The Allies now read U-boat operational traffic. For they had, more than a year before the theft, succeeded in solving the difficult U-boat systems, and – in one of the finest cryptanalytic achievements of the war – managed to read the intercepts on a current basis. For this, the cryptanalysts needed

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While it is obvious why Britain and the U.S. went to considerable pains to keep Ultra a secret until the end of the war, it has been a matter of some conjecture why Ultra was kept officially secret for 29 years thereafter, until 1974. During that period, the important contributions to the war effort

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from the surface of the sea, so it could not even locate U-boats attacking convoys on the surface on moonless nights; thus the surfaced U-boats were almost invisible, while having the additional advantage of being swifter than their prey. The new higher-frequency radar could spot conning towers, and

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The intelligence which has emanated from you before and during this campaign has been of priceless value to me. It has simplified my task as a commander enormously. It has saved thousands of British and American lives and, in no small way, contributed to the speed with which the enemy was routed and

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Would the Soviets meanwhile have defeated Germany, or Germany the Soviets, or would there have been stalemate on the eastern fronts? What would have been decided about the atom bomb? Not even counter-factual historians can answer such questions. They are questions which do not arise, because the war

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knew how short the Germans were of men, ammunition, food and above all fuel. When he put Rommel's picture up in his caravan he wanted to be seen to be almost reading his opponent's mind. In fact he was reading his mail." Over time, Ultra has become embedded in the public consciousness and Bletchley

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writes: "Had the... postwar governments of major powers realized ... how Allied victory in World War II had hung by a slender thread first spun by three mathematicians working on Enigma decryption for the general staff of a seemingly negligible power , they might have been more cautious in picking

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A succession of books by former participants and others followed. The official history of British intelligence in World War II was published in five volumes from 1979 to 1988, and included further details from official sources concerning the availability and employment of Ultra intelligence. It was

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gave an early garbled version of the myth of the purloined Enigma. According to Farago, it was thanks to a "Polish-Swedish ring the British obtained a working model of the 'Enigma' machine, which the Germans used to encipher their top-secret messages." "It was to pick up one of these machines that

1667:, on 25 May 1945, Churchill requested former recipients of Ultra intelligence not to divulge the source or the information that they had received from it, in order that there be neither damage to the future operations of the Secret Service nor any cause for the Axis to blame Ultra for their defeat. 1520:

Winterbotham's quoting of Eisenhower's "decisive" verdict is part of a letter sent by Eisenhower to Menzies after the conclusion of the European war and later found among his papers at the Eisenhower Presidential Library. It allows a contemporary, documentary view of a leader on Ultra's importance:

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Rommel was appointed Inspector General of the West, and he inspected all the defences along the Normandy beaches and send a very detailed message that I think was 70,000 characters and we decrypted it as a small pamphlet. It was a report of the whole Western defences. How wide the V shaped trenches

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In the Battle of the Atlantic, the precautions were taken to the extreme. In most cases where the Allies knew from intercepts the location of a U-boat in mid-Atlantic, the U-boat was not attacked immediately, until a "cover story" could be arranged. For example, a search plane might be "fortunate

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At Bletchley Park, extensive indices were kept of the information in the messages decrypted. For each message the traffic analysis recorded the radio frequency, the date and time of intercept, and the preamble—which contained the network-identifying discriminant, the time of origin of the message,

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cars. The following SCUs are listed: SCU1 (Whaddon Hall), SCU2 (France before 1940, India), SCU3 (RSS Hanslope Park), SCU5, SCU6 (possibly Algiers and Italy), SCU7 (training unit in the UK), SCU8 (Europe after D-day), SCU9 (Europe after D-day), SCU11 (Palestine and India), SCU12 (India), SCU13 and

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on 10 May 1940, the Germans made a very significant change in the indicator procedures for Enigma messages. However, the Bletchley Park cryptanalysts had anticipated this, and were able—jointly with PC Bruno—to resume breaking messages from 22 May, although often with some delay. The intelligence

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To disguise the source of the intelligence for the Allied attacks on Axis supply ships bound for North Africa, "spotter" submarines and aircraft were sent to search for Axis ships. These searchers or their radio transmissions were observed by the Axis forces, who concluded their ships were being

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setting. This allowed cross referencing of a new message with a previous one. The indices included message preambles, every person, every ship, every unit, every weapon, every technical term and of repeated phrases such as forms of address and other German military jargon that might be usable as

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This procedure also helped conceal the intelligence source from Allied personnel, who might give away the secret by careless talk, or under interrogation if captured. Along with the search mission that would find the Axis ships, two or three additional search missions would be sent out to other

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Ultra operations. John Agar, a historian of science and technology, states that by war's end 8,995 people worked at Bletchley Park. Iain Standen, Chief Executive of the Bletchley Park Trust, says of the work done there: "It was crucial to the survival of Britain, and indeed of the West." The

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Since it was British and, later, American message-breaking which had been the most extensive, the importance of Enigma decrypts to the prosecution of the war remained unknown despite revelations by the Poles and the French of their early work on breaking the Enigma cipher. This work, which was

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Ultra revealed that a major German air raid was planned for the night of 14 November 1940, and indicated three possible targets, including London and Coventry. However, the specific target was not determined until late on the afternoon of 14 November, by detection of the German radio guidance

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showing the tonnage of merchantmen sunk and the number of U-boats sunk in each month of the Battle of the Atlantic. The graphs cannot be interpreted unambiguously, because it is challenging to factor in many variables such as improvements in cipher-breaking and the numerous other advances in

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German suspicions of a security breach. To distract the Germans from the idea of a signals breach (such as Ultra), the Allies sent a radio message to a fictitious spy in Naples, congratulating him for this success. According to some sources the Germans decrypted this message and believed it.

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Most deciphered messages, often about relative trivia, were insufficient as intelligence reports for military strategists or field commanders. The organisation, interpretation and distribution of decrypted Enigma message traffic and other sources into usable intelligence was a subtle task.

1997:, p. 256, at the end of a short passage asserting the importance of Enigma-derived intelligence for Allied victory. The text there is: "Sans parler de cette entrevue historique, la guerre finie, où Sir Winston Churchill, présentant à S.M. George VI le Chef de l'I.S., prononça ces paroles; 665:

Although the volume of intelligence derived from this system was much smaller than that from Enigma, its importance was often far higher because it produced primarily high-level, strategic intelligence that was sent between Wehrmacht High Command (OKW). The eventual bulk decryption of

2005:: 'It is thanks to the secret weapon of General Menzies, put into use on all the fronts, that we won the war!'" It is not clear when, or on what occasion, Churchill made this statement or when Menzies later related it to Bertrand, who published this in 1973. In his 1987 book 1558:. To cite just one example, the historian Max Hastings states that "In 1941 alone, Ultra saved between 1.5 and two million tons of Allied ships from destruction." This would represent a 40 percent to 53 percent reduction, though it is not clear how this extrapolation was made. 1643:

By the 1970s, newer computer-based ciphers were becoming popular as the world increasingly turned to computerised communications, and the usefulness of Enigma copies (and rotor machines generally) rapidly decreased. Switzerland developed its own version of Enigma, known as

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The Allies were seriously concerned with the prospect of the Axis command finding out that they had broken into the Enigma traffic. The British were more disciplined about such measures than the Americans, and this difference was a source of friction between them.

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There has been controversy about the influence of Allied Enigma decryption on the course of World War II. It has also been suggested that the question should be broadened to include Ultra's influence not only on the war itself, but also on the post-war period.

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went as it did. But those historians who are concerned only with the war as it was must ask why it went as it did. And they need venture only a reasonable distance beyond the facts to recognise the extent to which the explanation lies in the influence of Ultra.

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German sources to assess just how much this was hurting the German war effort; thus Harris tended to see the directives to bomb specific oil and munitions targets as a "panacea" (his word) and a distraction from the real task of making the rubble bounce.

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units, and often provided advance warning of bombing raids (but not of their specific targets). These contributed to the British success. Dowding was bitterly and sometimes unfairly criticized by others who did not see Ultra, but he did not disclose his

459:, "The British code-breaking effort of the Second World War, formerly secret, is now one of the most celebrated aspects of modern British history, an inspiring story in which a free society mobilized its intellectual resources against a terrible enemy." 4781:

The first published account of the previously secret wartime operation, concentrating mainly on distribution of intelligence. It was written from memory and has been shown by subsequent authors, who had access to official records, to contain some

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in 1941, however, Bletchley Park was deciphering daily 2,000 Italian Hagelin messages. By the second half of 1941 30,000 Enigma messages a month were being deciphered, rising to 90,000 a month of Enigma and Fish decrypts combined later in the war.

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105-246), making it policy to declassify all Nazi war crime documents in their files; this was later amended to include the Japanese Imperial Government. As a result, more than 600 decrypts and translations of intercepted messages were disclosed;

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A second explanation relates to a misadventure of Churchill's between the World Wars, when he publicly disclosed information from decrypted Soviet communications. This had prompted the Soviets to change their ciphers, leading to a blackout.

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I should be very grateful, therefore, if you would express to each and every one of those engaged in this work from me personally my heartfelt admiration and sincere thanks for their very decisive contribution to the Allied war effort.

953:, the official historian for the British Secret Services in World War II, stated that "there is no truth in the much-publicized claim that the British authorities made use of the ‘Lucy’ ring ... to forward intelligence to Moscow". 1909:

had been ordered by U-boat Command to change course and proceed to North Africa, near Rabat, the submarine had missed the messages changing her assignment and had continued to the eastern coast of the U.S., her original destination.

771:) Hut 3 and distributed initially under the codeword "BONIFACE", implying that it was acquired from a well placed agent in Berlin. The volume of the intelligence reports going out to commanders in the field built up gradually. 1856:

Debate continues on whether, had postwar political and military leaders been aware of Ultra's role in Allied victory in World War II, these leaders might have been less optimistic about post-World War II military involvements.

945:, knew that Britain had broken Enigma. The "Lucy" ring was initially treated with suspicion by the Soviets. The information it provided was accurate and timely, however, and Soviet agents in Switzerland (including their chief, 826:

Mobile SLUs were attached to field army and air force headquarters and depended on radio communications to receive intelligence summaries. The first mobile SLUs appeared during the French campaign of 1940. An SLU supported the

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On 17 September 1940 an Ultra message reported that equipment at German airfields in Belgium for loading planes with paratroops and their gear was to be dismantled. This was taken as a clear signal that Sea Lion had been

1822:), from 11 January 1943 may have outlined the system and listed the number of Jews and others gassed at four death camps the previous year, but codebreakers did not understand the meaning of the message. In summer 1944, 1781:

have tried to establish when the Allies realized the full extent of Nazi-era extermination of Jews, and specifically, the extermination-camp system. In 1999, the U.S. Government passed the Nazi War Crimes Disclosure Act

1462:, his own codebreaking group, had partially broken Royal Navy traffic (including its convoy codes early in the war), and supplied enough information to support the idea that the Allies were unable to read Naval Enigma. 949:) eventually learned to take it seriously. However, the theory that the Lucy ring was a cover for Britain to pass Enigma intelligence to the Soviets has not gained traction. Among others who have rejected the theory, 823:, the US Strategic Air Forces in Europe (Wycombe Abbey) and other fixed headquarters in the UK. An SLU was operating at the War HQ in Valletta, Malta. These units had permanent teleprinter links to Bletchley Park. 4590: 1531:

I had hoped to be able to pay a visit to Bletchley Park in order to thank you, Sir Edward Travis, and the members of the staff personally for the magnificent service which has been rendered to the Allied cause.

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of scientific intelligence in the Air Ministry needed to show that the Germans were developing a radio guidance system for their bombers. Ultra intelligence then continued to play a vital role in the so-called

384:. Used properly, the German military Enigma would have been virtually unbreakable; in practice, shortcomings in operation allowed it to be broken. The term "Ultra" has often been used almost synonymously with " 1395:

During the Allied advance to Germany, Ultra often provided detailed tactical information, and showed how Hitler ignored the advice of his generals and insisted on German troops fighting in place "to the last

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countries, which remained convinced of the security of the remarkable cipher machines. Their traffic was not as secure as they believed, however, which is one reason the British made the machines available.

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in May 1941, the Ultra intelligence that a parachute landing was planned, and the exact day of the invasion, meant that heavy losses were inflicted on the Germans and that fewer British troops were captured.

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Ultra would never have got off the ground if we had not learned 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

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historian Robert Hanyok would conclude that Allied communications intelligence, "by itself, could not have provided an early warning to Allied leaders regarding the nature and scope of the Holocaust."

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of a great many people remained unknown, and they were unable to share in the glory of what is now recognised as one of the chief reasons the Allies won the war – or, at least, as quickly as they did.

714:" by the Americans, was used for highest-level Japanese diplomatic traffic. It produced a polyalphabetic substitution cipher, but unlike Enigma, was not a rotor machine, being built around electrical 1452:

received reports of "impossible" encounters between U-boats and enemy vessels which made him suspect some compromise of his communications. In one instance, three U-boats met at a tiny island in the

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was of unprecedented importance. It provided information as to where the enemy's forces were strongest and that the elaborate strategic deceptions had convinced Hitler and the German high command.

1802:, including those of Jews, but specifics were not made public for security reasons. Revelations about the concentration camps were gleaned from other sources, and were publicly reported by the 1867:. The Soviets received disguised Ultra information, but the existence of Ultra itself was not disclosed by the western Allies. The Soviets, who had clues to Ultra's existence, possibly through 1561:

Another view is from a history based on the German naval archives written after the war for the British Admiralty by a former U-boat commander and son-in-law of his commander, Grand Admiral

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and the person who controlled distribution of Ultra decrypts to the government): "It is thanks to the secret weapon of General Menzies, put into use on all the fronts, that we won the war!"

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carried out in the 1930s and continued into the early part of the war, was necessarily uninformed regarding further breakthroughs achieved by the Allies during the balance of the war.

1170:. It was not until June 1941 that Bletchley Park was able to read a significant amount of this traffic contemporaneously. Transatlantic convoys were then diverted away from the U-boat 3678: 2722:"Operation 'Citadel'—Kursk and Orel: The Greatest Tank Battle of the Second World War by Janusz Piekalkiewicz; translated by Michaela Nierhaus; (Presidio: $ 25; 288 pp., illustrated)" 2361: 431:

in attempting such conclusions, and some historians, such as Keegan, have said the shortening might have been as little as the three months it took the United States to deploy the

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The communications element of each SLU was called a "Special Communications Unit" or SCU. Radio transmitters were constructed at Whaddon Hall workshops, while receivers were the

891:, UK. Ultra summaries from Bletchley Park were sent over landline to the Section VIII radio transmitter at Windy Ridge. From there they were transmitted to the destination SLUs. 686:

In June 1940, the Italians were using book codes for most of their military messages, except for the Italian Navy, which in early 1941 had started using a version of the Hagelin

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and so had no need to use radio. This meant that those at Bletchley Park had some time to build up experience of collecting and starting to decrypt messages on the various

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The existence of Ultra was kept secret for many years after the war. Since the Ultra story was widely disseminated by Winterbotham in 1974, historians have altered the

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Most Ultra intelligence was derived from reading radio messages that had been encrypted with cipher machines, complemented by material from radio communications using

1845:, the first author to outline the influence of Enigma decryption on the course of World War II, likewise made the earliest contribution to an appreciation of Ultra's 5297: 4956: 4499:, wrote a number of papers on his 1932 break into Enigma and his subsequent work on the cipher, well into World War II, with his fellow mathematician-cryptologists, 1425:

found by conventional reconnaissance. They suspected that there were some 400 Allied submarines in the Mediterranean and a huge fleet of reconnaissance aircraft on

1406:, was not cleared for Ultra. After D-Day, with the resumption of the strategic bombing campaign over Germany, Harris remained wedded to area bombardment. Historian 1259: 5150: 1590:

during the war, two factors often argued against Ultra having shortened the overall war by a measure of years are the relatively small role it played in the

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The codeword "ULTRA" was adopted in June 1941. This codeword was reportedly suggested by Commander Geoffrey Colpoys, RN, who served in the Royal Navy's OIC.

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master spy, Boniface, who controlled a fictional series of agents throughout Germany. Information obtained through code-breaking was often attributed to the

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RN Ultra messages from the OIC to ships at sea were necessarily transmitted over normal naval radio circuits and were protected by one-time pad encryption.

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by the Americans, and by early 1942 the US Navy had made considerable progress in decrypting Japanese naval messages. The US Army also made progress on the

4517:(1984), "Summary of Our Methods for Reconstructing ENIGMA and Reconstructing Daily Keys, and of German Efforts to Frustrate Those Methods: Appendix C", in 1016:

In April 1940, Ultra information provided a detailed picture of the disposition of the German forces, and then their movement orders for the attack on the

4112: 801:, which operated Special Liaison Units (SLU) attached to major army and air force commands. The activity was organized and supervised on behalf of MI6 by 1733:

The British ban was finally lifted in 1974, the year that a key participant on the distribution side of the Ultra project, F. W. Winterbotham, published

5302: 4808: 1160:. Winston Churchill wrote "The only thing that ever really frightened me during the war was the U-boat peril." The decryption of Enigma signals to the 4076: 326:

for all such intelligence. The name arose because the intelligence obtained was considered more important than that designated by the highest British

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analyzes aspects of the question but then simply says, "It is impossible to calculate in terms of months or years how much Ultra shortened the war."

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equipment and techniques used to combat U-boats. Nonetheless, the data seem to favor the view of the former U-boat commander—that radar was crucial.

5014: 2278: 1273:, by providing him (before the battle) with a complete picture of Axis forces, and (during the battle) with Rommel's own action reports to Germany. 1153:

refused to believe it. The information did, however, help British planning, knowing that substantial German forces were to be deployed to the East.

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US Army Lieutenant Arthur J. Levenson, who worked on both Enigma and Tunny at Bletchley Park, said in a 1980 interview of intelligence from Tunny:

1174:, and the U-boat supply vessels were sunk. On 1 February 1942, Enigma U-boat traffic became unreadable because of the introduction of a different 4992: 1569:, developed in a joint British-American venture, which became operational in the spring of 1943. Earlier radar was unable to distinguish U-boat 5228: 1976:

The Hagelin C-38m (a development of the C-36) was the model used by the Italian Navy, and other Italian and Japanese ciphers and codes such as

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The exact influence of Ultra on the course of the war is debated; an oft-repeated assessment is that decryption of German ciphers advanced the

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chiefly edited by Harry Hinsley, with one volume by Michael Howard. There is also a one-volume collection of reminiscences by Ultra veterans,

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and gave the first published hint about the scale, mechanisation and operational importance of the Anglo-American Enigma-breaking operation:

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Berlin – and might have shortened the war by as much as two years had the U.S. atomic bomb program been unsuccessful." Military historian

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The first decryption of a wartime Enigma message, albeit one that had been transmitted three months earlier, was achieved by the Poles at

657:). These cipher systems were cryptanalysed, particularly Tunny, which the British thoroughly penetrated. It was eventually attacked using 5099: 4895: 4883: 4825: 4011: 1175: 855:

In 1940, special arrangements were made within the British intelligence services for handling BONIFACE and later Ultra intelligence. The

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could even be detected from airplanes. Some idea of the relative effect of cipher-breaking and radar improvement can be obtained from

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The game of the foxes: British and German intelligence operations and personalities which changed the course of the Second World War

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At least three explanations exist as to why Ultra was kept secret so long. Each has plausibility, and all may be true. First, as

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By 1945, most German Enigma traffic could be decrypted within a day or two, yet the Germans remained confident of its security.

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machine. Having developed a similar machine, the Japanese did not use the Enigma machine for their most secret communications.

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by no less than two years. Hinsley, who first made this claim, is typically cited as an authority for the two-year estimate.

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By the end of the war, there were about 40 SLUs serving commands around the world. Fixed SLUs existed at the Admiralty, the

4450: 5077: 1490: 3949: 1073:, for Ultra reports. Ultra intelligence kept him informed of German strategy, and of the strength and location of various 4944: 1045:

is directed at position 53 degrees 24 minutes north and 1 degree west"). This was the definitive piece of evidence that

5087: 4932: 4860: 4706: 4609: 1303: 740: 629: 613: 538:

and were widely thought to be unbreakable in the 1920s, when a variant of the commercial Model D was first used by the

2153: 2062:, vol. L, no. 2, 2005, p. 241). A kindred point concerning postwar American triumphalism is made by British historian 1830:

analyst, interpreted the intelligence as an "incremental increase in persecution rather than ... extermination".

5132: 4937: 4794: 4775: 4664: 4639: 4599: 4480: 4432: 4363: 4303: 4062: 4044: 4033:

The Essential Turing: Seminal Writings in Computing, Logic, Philosophy, Artificial Intelligence, and Artificial Life

3912: 3879: 3861: 3827: 3802: 3145: 2309: 2190: 2163: 1769:; the seven decades' delay had been due to their "continuing sensitivity... It wouldn't have been safe to release ." 1186: 1921:. MK was the CIA's designation for its Technical Services Division and Ultra was in reference to the Ultra project. 446:, writing in the 21st century, states, "Because he had the invaluable advantage of being able to read Field Marshal 2035:

Coincidentally, German success in this respect almost exactly matched in time an Allied blackout from Naval Enigma.

1788: 1756:

of his birth, includes a short film of statements by half a dozen participants and historians of the World War II

5020: 4017: 3076:

Only a few days before the battle, Ultra confirmed that Montgomery's estimate of Rommel's intentions was correct.

1359:

and even after D-Day still believed Normandy was only a feint, with the main invasion to be in the Pas de Calais.

1062: 836: 832: 609: 1206:

and German naval Enigma decrypts, helped sink about half of the ships supplying the Axis forces in North Africa.

5307: 4682: 4397:

This is the standard reference on the crucial foundations laid by the Poles for World War II Enigma decryption.

439: 360: 993:

that these messages yielded was of little operational use in the fast-moving situation of the German advance.

5127: 4817: 1330: 3893:

Enigma ou la plus grande énigme de la guerre 1939–1945 (Enigma: The Greatest Enigma of the War of 1939–1945)

3396: 1849:

influence, which now continues into the 21st century—and not only in the postwar establishment of Britain's

1388:

Ultra warned of the major German counterattack at Mortain, and allowed the Allies to surround the forces at

5250: 4170:

Eavesdropping on Hell: Historical Guide to Western Communications Intelligence and the Holocaust, 1939–1945

1827: 1687:("Battle for Secrets") first revealed Enigma had been broken by Polish cryptologists before World War II. 1591: 1587: 1407: 2957: 5271: 5256: 5094: 1270: 1005: 719: 604:

At Bletchley Park, some of the key people responsible for success against Enigma included mathematicians

521: 412: 385: 195: 58: 2721: 2397: 2022:

radio intercepting and direction finding facilities. These units were formed from assets of the former

1803: 443: 4377:

Enigma: How the German Machine Cipher was Broken, and how it was Read by the Allies in World War Two,

4317:

The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

4296:

The Codebreakers: The Comprehensive History of Secret Communication from Ancient Times to the Internet

1342:

were to stop tanks, and how much barbed wire. Oh, it was everything and we decrypted it before D-Day.

782:'s Operational Intelligence Centre (OIC), which distributed it initially under the codeword "HYDRO". 5082: 4873: 2402: 1823: 1798:, decrypts in August 1941 alerted British authorities to the many massacres in occupied zones of the 1433:

areas, so that crews would not begin to wonder why a single mission found the Axis ships every time.

1310: 985: 4527:

Enigma: How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two

4168: 3473: 1917:, a series of experiments on human subjects to develop drugs for use in interrogations, was renamed 1485:

messages daily. The more successful the code breakers were, the more labor was required. Some 8,000

370: 5261: 2054:

The Polish Underground Army, the Western Allies, and the Failure of Strategic Unity in World War II

1905:

was unravelled in part through the analysis of Ultra intercepts, which demonstrated that, although

1649: 1252: 1149:, the German invasion of the USSR. Although this information was passed to the Soviet government, 5322: 5276: 5004: 4518: 4372: 4013:

Commentary: Poland's Decisive Role in Cracking Enigma and Transforming the UK's SIGINT Operations

3905:

Very Special Intelligence: The Story of the Admiralty's Operational Intelligence Centre 1939–1945

3661: 1749: 1680: 1486: 1371: 1263: 1237: 1182: 1171: 543: 261: 4383:, Warsaw, Książka i Wiedza, 1979, supplemented with appendices by Marian Rejewski, Frederick, MD 1012:

Some of the contributions that Ultra intelligence made to the Allied successes are given below.

4564: 3660:

A 16-page pamphlet of that title, summarizing Turing's life and work, is available free at the

3327: 1887: 1880: 1697: 1579: 1555: 1157: 1132: 973: 654: 428: 327: 323: 188: 120: 68: 2299: 491:

predominating, as they used radio more and their operators were particularly ill-disciplined.

5327: 4916: 4868: 4848: 4268: 4256: 3460: 2775: 2049: 1945: 1811: 1502: 1321: 1046: 880: 582: 535: 393: 291: 743:

in 1943, including codes used by supply ships, resulting in heavy losses to their shipping.

4976: 4926: 4522: 2295: 2044: 1940: 1795: 1603: 1317: 1146: 760: 724: 420: 399:

Many observers, at the time and later, regarded Ultra as immensely valuable to the Allies.

365: 295: 93: 83: 73: 48: 4656: 4650: 4567:(1992), "The London Operation: Recollections of a Historian", in Chalou, George C. (ed.), 996:

Decryption of Enigma traffic built up gradually during 1940, with the first two prototype

641:

systems for strategic point-to-point radio links, to which the British gave the code-name

8: 5266: 4949: 4865: 4333: 4312: 4291: 1624: 1348: 1296: 1230: 1089:

radio networks provided a great deal of indirect intelligence about the Germans' planned

1066: 1051: 967: 820: 735:

The chief fleet communications code system used by the Imperial Japanese Navy was called

650: 642: 567: 3941:

A short account of World War II cryptology which covers more than just the Enigma story.

1473: 4786: 4763: 4500: 3968: 3945: 2419: 2272: 2207: 2068: 1956: 1842: 1554:

There is wide disagreement about the importance of codebreaking in winning the crucial

1403: 1375: 1352: 1131:

Ultra intelligence greatly aided the Royal Navy's victory over the Italian navy in the

1090: 1070: 805: 451: 416: 78: 4379:

edited and translated by Christopher Kasparek [a revised and augmented translation of

898:, made in the USA. The SCUs were highly mobile and the first such units used civilian 4771: 4750: 4728: 4702: 4696: 4678: 4660: 4635: 4617: 4595: 4572: 4550: 4530: 4486: 4476: 4438: 4428: 4409: 4387: 4359: 4353: 4349: 4320: 4299: 4278: 4236: 4219: 4189: 4154: 4136: 4097: 4072: 4058: 4040: 3997: 3989: 3976: 3931: 3925: 3921: 3908: 3875: 3857: 3823: 3798: 3712: 3193: 3141: 2305: 2186: 2159: 2135:"The Imitation Game: how Alan Turing played dumb to fool US intelligence - David Cox" 2058: 1914: 1860: 1778: 1595: 1566: 1436:

Other deceptive means were used. On one occasion, a convoy of five ships sailed from

1356: 1190: 1121: 1114: 1058: 779: 658: 472: 400: 4272: 2423: 1819: 1236:

Deciphered JN-25 messages allowed the U.S. to turn back a Japanese offensive in the

946: 499: 4961: 3888: 3730: 2411: 2026:, after it was reassigned to MI6 and they were not involved in Ultra dissemination. 1815: 1727: 1692: 1284: 1241: 1021: 989: 906:

The cryptographic element of each SLU was supplied by the RAF and was based on the

844: 694:. This was broken from June 1941 onwards by the Italian subsection of GC&CS at 468: 4712:

An early publication containing several misapprehensions that are corrected in an

4456: 4202:

Hinsley, F. H. "Introduction: The Influence of Ultra in the Second World War". In

1663:

The third explanation is given by Winterbotham, who recounts that two weeks after

578: 5243: 4692: 4544: 4514: 4504: 4496: 4089: 3852: 3820:

Someone Is Out to Get Us: A Not So Brief History of Cold War Paranoia and Madness

3071: 3067: 2082: 1918: 1902: 1872: 1783: 1711: 1382: 1365: 1277: 1247:

Ultra contributed very significantly to the monitoring of German developments at

1139: 942: 934: 888: 755:

Average numbers of daily Ultra dispatches to field commanders during World War II

715: 586: 574: 408: 98: 4591:

The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography

4252:

Transcript of a lecture given on Tuesday 19 October 1993 at Cambridge University

3190:

Code Girls: The Untold Story of the American Women Code Breakers of World War II

2155:

The Secrets of Station X: How the Bletchley Park codebreakers helped win the war

1429:. In fact, there were only 25 submarines and at times as few as three aircraft. 1000:

being delivered in March and August. The traffic was almost entirely limited to

5055: 4720: 3900: 3488: 1814:

offices in Switzerland a year or more later. A decrypted message referring to "

1757: 1645: 1478: 1389: 1292: 1288: 1102: 768: 695: 527: 404: 381: 315: 288: 226: 105: 38: 3138:

The battle for North Africa: El Alamein and the turning point for World War II

1562: 1449: 941:

of German radio traffic. The Soviets, however, through an agent at Bletchley,

5291: 4742: 4616:, Pan Grand Strategy Series (Pan Books ed.), London: Pan MacMillan Ltd, 4442: 4232: 4211: 4181: 4028: 4024: 3847: 1898: 1876: 1570: 1453: 1399: 1226: 1150: 1017: 950: 938: 926: 860: 802: 707: 687: 675: 646: 635: 531: 484: 424: 423:, at war's end describing Ultra as having been "decisive" to Allied victory. 389: 243: 4490: 1248: 925:

An intriguing question concerns the alleged use of Ultra information by the

5317: 4401: 2772:"Bletchley Park Archives: Government Code & Cypher School Card Indices" 2077: 2063: 1799: 1194: 911: 895: 884: 816: 797:

Dissemination of Ultra intelligence to field commanders was carried out by

547: 456: 447: 377: 115: 1101:

signals. Unfortunately, countermeasures failed to prevent the devastating

1033:

KLEVE IST AUF PUNKT 53 GRAD 24 MINUTEN NORD UND EIN GRAD WEST EINGERICHTET

455:

Park has become a significant visitor attraction. As stated by historian

5060: 4585: 3675:"Nazi War Crimes and Japanese Imperial Government Disclosure Act of 2000" 3559: 1636: 1608: 1599: 1276:

Ultra provided evidence that the Allied landings in French North Africa (

930: 711: 667: 638: 617: 605: 432: 307: 110: 1448:

Some Germans had suspicions that all was not right with Enigma. Admiral

254: 220: 16:

British designation for intelligence from decrypted enemy communications

1894: 1868: 1807: 1635:, after the war, surplus Enigmas and Enigma-like machines were sold to 1269:

Ultra also contributed to the success of Montgomery's offensive in the

1030: 812: 671: 585:

and their techniques for decrypting ciphers to the French and British.

555: 539: 503:

A typical Bletchley intercept sheet, before decryption and translation.

476: 88: 4336:(29 December 1974), "Enigma Unwrapped: Review of F. W. Winterbotham's 475:. In the early phases of the war, particularly during the eight-month 1753: 1752:

exhibit, "Code Breaker: Alan Turing's Life and Legacy", marking the

1575: 868: 551: 488: 339: 4605:

This provides a description of the Enigma, other ciphers, and codes.

4408:(Penguin Classic Military History ed.), London: Penguin Group, 2415: 1069:, had a teleprinter link from Bletchley Park to his headquarters at 507: 4529:(2 ed.), University Publications of America, pp. 241–45, 4452:

Codebreaking and Secret Weapons in World War II: Chapter IV 1941–42

1993:

The original source for this quote is from Gustave Bertrand's book

1864: 1863:

suggests that Ultra may have contributed to the development of the

1722:

Later, the 1973 public disclosure of Enigma decryption in the book

1458: 1347:

Both Enigma and Tunny decrypts showed Germany had been taken in by

1335:, was entirely built on prompt deciphering of German naval signals. 1110: 981: 751: 480: 152: 4473:

The Secret Wireless War: The Story of MI6 Communications 1939–1945

3927:

Battle of wits: The Complete Story of Codebreaking in World War II

2984: 2182:

Battle of Wits: The Complete Story of Codebreaking in World War II

1730:

generated pressure to discuss the rest of the Enigma–Ultra story.

1652:(NSA) retired the last of its rotor-based encryption systems, the 5238: 4569:

The Secrets War: The Office of Strategic Services in World War II

2073: 1664: 1309:

The part played by Ultra intelligence in the preparation for the

1219:) had captured all of the German agents in Britain, and that the 984:

on 17 January 1940. Little had been achieved by the start of the

899: 559: 487:. German Enigma messages were the main source, with those of the 299: 4188:(OU Press paperback ed.), Oxford: Oxford University Press, 3776: 3774: 3426: 3323:

Bletchley park archives: October 1943 : Not all our own way

2398:"Colossal Genius: Tutte, Flowers, and a Bad Imitation of Turing" 1445:

enough" to sight the U-boat, thus explaining the Allied attack.

966:

the callsign of the originating and receiving stations, and the

237: 3154: 2954:"Seventy Years Ago This Month at Bletchley Park: December 1940" 2215: 1977: 1437: 1161: 1156:

Ultra intelligence made a very significant contribution in the

1037: 883:, who from 1938 to 1946 was head of MI6 Section VIII, based at 847:. This SLU was commanded by Squadron Leader F.W. "Tubby" Long. 563: 562:

and German diplomats used Enigma machines in several variants.

4055:

The Enemy Within: A History of Spies, Spymasters and Espionage

3068:"The contribution of Intelligence at the Battle of Alam Halfa" 1240:

in April 1942 and set up the decisive American victory at the

30: 3771: 3302: 2886: 2874: 2814: 2104: 2102: 1981: 1935: 1930: 1594:, and the completely independent development of the U.S.-led 1426: 1283:

A JN-25 decrypt of 14 April 1943 provided details of Admiral

1125: 1117:

so that he could observe the raid from the Air Ministry roof.

997: 907: 840: 775: 764: 736: 691: 322:

eventually became the standard designation among the western

303: 157: 145: 140: 135: 130: 125: 4176:, Center for Cryptographic History, National Security Agency 3874:(Pimlico: New and Enlarged ed.), London: Random House, 3353: 3093: 2478: 2442: 573:

German military Enigma was first broken in December 1932 by

5221: 5216: 5208: 5203: 5195: 5190: 4986: 4419:

Focuses on the battle-field exploitation of Ultra material.

4114:

Oral History Interview NSA-OH-40-80 with Arthur J. Levenson

3759: 3278: 3044: 2234: 2232: 2230: 1850: 1762: 1653: 1648:, and used it into the late 1970s, while the United States 1592:

Eastern Front conflict between Germany and the Soviet Union

4879:

National Domestic Extremism and Disorder Intelligence Unit

3582: 3566:. Basingstoke, Hampshire: Macmillan Press. pp. 96–99. 3384:

Sharing the Burden—Women in Cryptology During World War II

2934: 2838: 2638: 2575: 2495: 2493: 2466: 2099: 1707:

the help of a mass of machinery that filled two buildings.

1696:

described the 1944 capture of a Naval Enigma machine from

479:, the Germans could transmit most of their messages using 388:". However, Ultra also encompassed decrypts of the German 5185: 5180: 5175: 5170: 5165: 5160: 5155: 4957:

1st Intelligence, Surveillance and Reconnaissance Brigade

4905: 4835: 4634:. Fortress. Vol. 16. Oxford, UK: Osprey Publishing. 3506: 2740: 2454: 2301:

A Century of Spies: Intelligence in the Twentieth Century

2023: 1999:

qui m'ont été rapportées par le général Menziès lui-même:

1216: 1215:

transmissions confirmed that Britain's Security Service (

1120:

Ultra intelligence considerably aided the British Army's

864: 856: 798: 356: 4816: 4319:(2nd Revised ed.), New York: Simon & Schuster, 3795:

Conspiracies and Conspiracy Theories in American History

3254: 3218: 3166: 3020: 3008: 2898: 2802: 2650: 2318: 2227: 570:

of GC&CS is said to have broken one before the war.

4741:

Wilkinson, Patrick (1993), "Italian naval ciphers", in

4546:

The Storm of War: A New History of the Second World War

3872:

Behind the Battle: Intelligence in the War with Germany

3386:, Jennifer Wilcox, Center for Cryptologic History, 1998 2565: 2563: 2561: 2559: 2557: 2490: 2018:

In addition, there were SCU3 and SCU4, which supported

1468: 1145:

Ultra intelligence fully revealed the preparations for

1113:, was told that London might be bombed and returned to 879:

The communications system was founded by Brigadier Sir

634:

In June 1941, the Germans started to introduce on-line

369:

for its decrypts from Japanese sources, including the "

3630: 3618: 3606: 2956:. Bletchley Park National Codes Centre. Archived from 2790: 2752: 2691: 2689: 2604: 2602: 2587: 2342: 1995:

Enigma ou la plus grande énigme de la guerre 1939–1945

867:

this intelligence was handled by "Section V" based at

759:

Army- and Air Force-related intelligence derived from

511:

A typical Bletchley intercept sheet, after decryption.

363:

from the Boniface network. The U.S. used the codename

3642: 3365: 3290: 2922: 2701: 2517: 2505: 1879:, may thus have felt still more distrustful of their 1299:, killing this man who was regarded as irreplaceable. 3797:. Santa Barbara, California: ABC-CLIO. p. 200. 3594: 3266: 3242: 3230: 3206: 3117: 3105: 3081: 3032: 2996: 2972: 2862: 2614: 2554: 2430: 2330: 1493:

to encourage women to stay at home and have babies.

4107:

Has been criticised for inaccuracy and exaggeration

4078:

The Historical Impact of Revealing the Ultra Secret

2850: 2826: 2686: 2674: 2662: 2626: 2599: 2244: 2003:

that were reported to me by General Menzies himself

1355:. They revealed the Germans did not anticipate the 1291:, and on 18 April, a year to the day following the 1200:Ultra intelligence from Hagelin decrypts, and from 392:that were used by the German High Command, and the 4084:, Parameters, Journal of the U.S. Army War College 3389: 3341: 2541: 2362:"Bletchley Park Welcomes 2015'S 200,000th Visitor" 2304:. New York: Oxford University Press. p. 296. 2114: 2007:"C": The Secret Life of Sir Stewart Graham Menzies 1886:The mystery surrounding the discovery of the sunk 5118:Intelligence and Security Committee of Parliament 3994:The Second World War, Volume 2: Their Finest Hour 3570: 1586:While Ultra certainly affected the course of the 1370:division in the planned dropping zone for the US 1197:forces from reaching Cairo in the autumn of 1941. 5298:Telecommunications-related introductions in 1941 5289: 4747:Codebreakers: The inside story of Bletchley Park 4422: 4186:Codebreakers: The inside story of Bletchley Park 3489:"The Influence of ULTRA in the Second World War" 3414: 3359: 2910: 2364:. Bletchley Park. 26 August 2015. Archived from 1266:by providing warning of Rommel's planned attack. 3822:(1st ed.). New York: Twelve. p. 264. 1477:Women cryptologists at work in the U.S. Army's 4571:, Washington, DC: Government Printing Office, 4238:The Influence of ULTRA in the Second World War 3793:Fee, Christopher R.; Webb, Jeffrey B. (2019). 2529: 5123:Independent Reviewer of Terrorism Legislation 4802: 4614:Station X: The Codebreakers of Bletchley Park 4475:, St Leonards-on-Sea, East Sussex: UPSO Ltd, 4203: 4180: 3564:The Effect of Science on the Second World War 3527:All Hell Let Loose: The World at War, 1939–45 2719: 2108: 1124:victory over the much larger Italian army in 645:. Several systems were used, principally the 419:quoted the western Supreme Allied Commander, 312:Government Code and Cypher School (GC&CS) 196: 5073:Foreign, Commonwealth and Development Office 4762: 4698:The Hut Six story: Breaking the Enigma codes 4216:British intelligence in the Second World War 3975:, Kidderminster, England: M & MBaldwin, 3967: 3765: 3588: 3512: 3308: 3284: 3160: 3050: 2990: 2940: 2892: 2880: 2844: 2820: 2644: 2324: 2290: 2288: 2277:: CS1 maint: multiple names: authors list ( 2221: 1363: 1328: 1220: 1210: 1201: 1165: 1084: 1074: 1040: 1028: 859:started "Special Research Unit B1(b)" under 710:theatre, a Japanese cipher machine, called " 4884:National Counter Terrorism Policing Network 4563: 3753: 1745:(1993), edited by Hinsley and Alan Stripp. 1304:Japanese Army’s "2468" water transport code 763:(SIGINT) sources—mainly Enigma decrypts in 530:" refers to a family of electro-mechanical 4967:30 Commando Information Exploitation Group 4809: 4795: 4629: 4259:(28 August 1976), "The raid on Coventry", 4151:Colossus: Bletchley Park's Greatest Secret 4133:Intelligence and strategy: selected essays 3996:(Penguin Classics ed.), p. 529, 3944: 3544:. London: Her Majesty's Stationery Office. 3440:. National Security Agency. Archived from 3061: 3059: 2656: 2548: 1415: 1233:. This enabled major deception operations. 1164:was much more difficult than those of the 462: 203: 189: 5303:1941 establishments in the United Kingdom 5066:Office for Security and Counter-Terrorism 4740: 4701:, Harmondsworth, England: Penguin Books, 4427:, Hersham, Surrey: Ian Allan Publishing, 4348: 4218:, Cambridge: Cambridge University Press, 3988: 3920: 3780: 3542:The U-Boat war in the Atlantic, 1939–1945 3435:"The Cryptographic Mathematics of Enigma" 3260: 3172: 3099: 3026: 3014: 2808: 2581: 2294: 2285: 2178: 1772: 874: 767:—was compiled in summaries at GC&CS ( 4855:National Ballistics Intelligence Service 4691: 4513: 4508: 4371: 4210: 4023: 3887: 3648: 3529:. London: HarperPress. pp. 275–276. 3524: 3183: 3181: 3140:. Indiana University Press. p. 95. 2796: 2569: 2535: 2499: 2484: 2472: 2460: 2448: 2391: 2389: 2387: 2385: 2383: 1472: 1128:between December 1940 and February 1941. 850: 750: 506: 498: 4672: 4542: 4470: 4231: 4201: 4071: 3869: 3846: 3792: 3558: 3552: 3539: 3056: 2978: 2928: 2758: 2720:Piekalkiewicz, Janusz (9 August 1987). 2695: 2593: 2511: 2348: 2336: 2250: 2238: 1833: 5290: 4987:Government Communications Headquarters 4842:National Protective Security Authority 4725:GCHQ: The Secret Wireless War, 1900–86 4648: 4549:. Penguin Books Limited. p. 501. 4507:. Most of Rejewski's papers appear in 4448: 4386:, University Publications of America, 4166: 4148: 4130: 4110: 4088: 4052: 3899: 3741: 3699: 3636: 3624: 3612: 3432: 3371: 3347: 3296: 3272: 3236: 3135: 2746: 2707: 2620: 2523: 2262: 1951:Signals intelligence in modern history 1674: 1614: 956: 4790: 4632:The fortifications of Malta 1530–1945 4608: 4584: 4400: 4298:(1st ed.), New York: Macmillan, 4267: 4009: 3817: 3248: 3224: 3212: 3187: 3178: 3123: 3111: 3087: 3065: 3038: 3002: 2904: 2868: 2856: 2832: 2436: 2395: 2380: 2151: 2120: 1351:, the deception operation to protect 788: 342:had been used for such intelligence. 5313:Signals intelligence of World War II 5151:Directorate of Military Intelligence 4818:United Kingdom intelligence agencies 4719: 4332: 4311: 4290: 4255: 3600: 3576: 3420: 3066:Smith, Kevin D. (July–August 2002). 2916: 2680: 2668: 2632: 2608: 2069:Inferno: The World at War, 1939–1945 1496: 1491:Cross of Honour of the German Mother 1469:Role of women in Allied codebreaking 1362:Information that there was a German 933:and apparently operated by one man, 380:cipher traffic was encrypted on the 4749:, Oxford: Oxford University Press, 4727:, London: Weidenfeld and Nicolson, 4135:(illustrated ed.), Routledge, 4039:, Oxford: Oxford University Press, 3486: 2179:Budiansky, Stephen (27 June 2018). 2132: 1679:In 1967, Polish military historian 1027:An Ultra decrypt of June 1940 read 13: 4933:Defence Intelligence Fusion Centre 4861:National Fraud Intelligence Bureau 4111:Farley, R. D. (25 November 1980), 2209:Crypto AG: Hagelin cipher machines 2152:Smith, Michael (31 October 2011). 630:Cryptanalysis of the Lorenz cipher 614:British Tabulating Machine Company 536:polyalphabetic substitution cipher 450:'s Enigma communications, General 14: 5339: 5133:Investigatory Powers Commissioner 4938:Joint Intelligence Training Group 3713:"Poland and her Jews 1941 - 1944" 4652:Dresden:Tuesday 13 February 1945 4455:, Nautical Brass, archived from 4277:, London: Book Club Associates, 3811: 3786: 3747: 3735: 3723: 3705: 3693: 3667: 3654: 2038: 1540:eventually forced to surrender. 778:was forwarded from Hut 4 to the 623: 298:obtained by breaking high-level 253: 236: 219: 29: 5021:Joint Terrorism Analysis Centre 5015:Joint Intelligence Organisation 4423:Mallmann-Showell, J.P. (2003), 4018:Royal United Services Institute 3839: 3533: 3518: 3480: 3377: 3314: 3129: 2946: 2764: 2713: 2354: 2256: 2133:Cox, David (28 November 2014). 2029: 2012: 1726:by French intelligence officer 1229:which MI5 controlled under the 837:RAF Advanced Air Striking Force 746: 718:. It was broken by the US Army 334:) and so was regarded as being 4993:National Cyber Security Centre 4770:, New York: Harper & Row, 4655:, London: Bloomsbury, p. 3192:. New York, Boston: Hachette. 2396:Haigh, Thomas (January 2017). 2199: 2172: 2145: 2126: 1987: 1970: 1487:women worked at Bletchley Park 988:in April. At the start of the 843:commanded by Air Vice-Marshal 440:historiography of World War II 1: 5229:Naval Intelligence Department 5128:Investigatory Powers Tribunal 4184:; Stripp, Alan, eds. (1993), 2093: 2076:"After WORDS" interview with 1302:Ship position reports in the 1138:Although the Allies lost the 1004:messages. By the peak of the 583:reconstructed Enigma machines 351:was used as a cover name for 5251:Special Operations Executive 5040:Joint Intelligence Committee 4630:Stephenson, Charles (2004). 4355:The Second Oldest Profession 4131:Ferris, John Robert (2005), 2267:. New York: Alfred A. Knopf. 2086:, broadcast 4 December 2011. 2048:their own wars." (Review of 1378:led to a change of location. 1185:, Ultra intelligence helped 271:were broken by the Allies to 7: 5272:Special Reconnaissance Unit 5257:Diplomatic Wireless Service 5234:Naval Intelligence Division 5095:Single Intelligence Account 4906:Secret Intelligence Service 4204:Hinsley & Stripp (1993) 3493:Keith Lockstone's home page 1924: 1327:sank the German battleship 1271:Second Battle of El Alamein 1225:still believed in the many 1083:Decryption of traffic from 1006:Battle of the Mediterranean 829:British Expeditionary Force 720:Signal Intelligence Service 701: 522:Cryptanalysis of the Enigma 413:Secret Intelligence Service 10: 5344: 5100:National Security Strategy 4471:Pidgeon, Geoffrey (2003), 4425:German Naval Code Breakers 4342:New York Times Book Review 4167:Hanyok, Robert J. (2004), 4153:, London: Atlantic Books, 2263:Keegan, John, Sir (2003). 2080:, U.S. editor of London's 1804:Polish government-in-exile 1761:Departmental Historian at 1381:Ultra assisted greatly in 1297:his aircraft was shot down 1093:to invade England in 1940. 910:cryptographic machine and 774:Naval Enigma decrypted in 681: 627: 519: 403:was reported to have told 269:Three cipher machines that 5141: 5108: 5083:Chiefs of Staff Committee 5051:National Security Adviser 5046:National Security Council 5030: 5003: 4975: 4915: 4894: 4874:Counter Terrorism Command 4824: 4649:Taylor, Fredrick (2005), 4594:, London: Fourth Estate, 4057:. Bloomsbury Publishing. 3540:Hessler, Günther (1989). 2403:Communications of the ACM 2195:– via Google Books. 2168:– via Google Books. 2109:Hinsley & Stripp 1993 1631:review of Winterbotham's 1311:Allied invasion of Sicily 986:Allied campaign in Norway 515: 494: 407:, when presenting to him 294:in June 1941 for wartime 24:The Enigma cipher machine 5262:Far East Combined Bureau 4543:Roberts, Andrew (2009). 4525:; Frederick, MD (eds.), 4358:, W.W. Norton & Co, 3907:, Sphere Books Limited, 3870:Bennett, Ralph (1999) , 1963: 1650:National Security Agency 1627:pointed out in his 1974 1253:V-1 and V-2 intelligence 1209:Ultra intelligence from 1065:, Commander-in-Chief of 674:and electrical engineer 390:Lorenz SZ 40/42 machines 273:yield Ultra intelligence 5277:Military Reaction Force 4745:; Stripp, Alan (eds.), 4565:Schlesinger, Arthur Jr. 3895:, Paris: Librairie Plon 3433:Miller, A. Ray (2001). 3401:Bletchley Park Research 2265:Intelligence in Warfare 2158:. Biteback Publishing. 1690:In 1967, David Kahn in 1503:end of the European war 1416:Safeguarding of sources 1372:101st Airborne Division 1280:) were not anticipated. 1264:Battle of Alam el Halfa 1238:Battle of the Coral Sea 1183:Western Desert Campaign 920: 794:control dissemination. 463:Sources of intelligence 328:security classification 4673:Tarrant, V.E. (1995). 4449:Momsen, Bill (2007) , 4053:Crowdy, Terry (2011). 3525:Hastings, Max (2011). 3468:Cite journal requires 2993:, pp. 67–69, 187. 2185:. Simon and Schuster. 2024:Radio Security Service 1888:German submarine 1773:Holocaust intelligence 1709: 1656:series, in the 1980s. 1556:Battle of the Atlantic 1552: 1528:Dear General Menzies: 1518: 1481: 1400:Arthur "Bomber" Harris 1364: 1344: 1329: 1251:and the collection of 1221: 1211: 1202: 1176:4-rotor Enigma machine 1166: 1158:Battle of the Atlantic 1133:Battle of Cape Matapan 1085: 1075: 1041: 1029: 875:Radio and cryptography 756: 602: 512: 504: 429:counterfactual history 310:communications at the 5308:Military intelligence 4869:Specialist Operations 4849:National Crime Agency 4523:Kasparek, Christopher 4149:Gannon, Paul (2006), 4037:The Secrets of Enigma 4027:(2004), "Enigma", in 3818:Brown, Brian (2019). 3360:Mallmann-Showell 2003 3136:Harper, Glyn (2017). 2296:Richelson, Jeffery T. 2050:Michael Alfred Peszke 1946:Military intelligence 1779:Holocaust researchers 1716:The Game of the Foxes 1704: 1523: 1507: 1476: 1402:, officer commanding 1339: 1287:forthcoming visit to 1258:Ultra contributed to 881:Richard Gambier-Parry 851:Intelligence agencies 754: 741:Japanese Army's codes 591: 532:rotor cipher machines 510: 502: 292:military intelligence 229:out of its wooden box 4927:Defence Intelligence 4716:in the 1997 edition. 4010:Comer, Tony (2021), 3950:"Giving Hitler Hell" 3397:"Women Codebreakers" 3188:Mundy, Liza (2017). 2487:, pp. 234, 235. 2451:, pp. 231, 232. 2224:, pp. 154, 191. 2045:Christopher Kasparek 1941:Magic (cryptography) 1834:Postwar consequences 1796:Operation Barbarossa 1714:'s 1971 best-seller 1604:Jeffrey T. Richelson 1550:Dwight D. Eisenhower 1318:Battle of North Cape 1147:Operation Barbarossa 1061:, Air Chief Marshal 761:signals intelligence 722:and disseminated as 579:Polish Cipher Bureau 421:Dwight D. Eisenhower 296:signals intelligence 69:Polish Cipher Bureau 5267:Force Research Unit 5078:Ministry of Defence 4950:Joint Support Group 4866:Metropolitan Police 4764:Winterbotham, F. W. 4519:Kozaczuk, Władysław 4373:Kozaczuk, Władysław 3969:Calvocoressi, Peter 3946:Brzezinski, Matthew 3783:, pp. 173–175. 3227:, pp. 227–230. 3163:, pp. 187–188. 3102:, pp. 315–316. 2907:, pp. 146–153. 2749:, pp. 307–309. 1913:In 1953, the CIA's 1675:Postwar disclosures 1615:Postwar suppression 1349:Operation Bodyguard 1316:The success of the 1231:Double Cross System 1067:RAF Fighter Command 1052:Battle of the Beams 957:Use of intelligence 929:, headquartered in 821:RAF Fighter Command 651:Geheimfernschreiber 534:. These produced a 285:was the designation 246:with covers removed 244:Lorenz SZ42 machine 4945:Intelligence Corps 4677:. London: Cassel. 4459:on 26 January 2001 4350:Knightley, Phillip 3990:Churchill, Winston 3922:Budiansky, Stephen 3681:on 3 February 2016 3447:on 17 January 2009 3074:. pp. 74–77. 2475:, pp. 242–43. 2368:on 2 February 2017 1957:The Imitation Game 1843:F. W. Winterbotham 1824:Arthur Schlesinger 1681:Władysław Kozaczuk 1482: 1404:RAF Bomber Command 1376:Operation Overlord 1353:Operation Overlord 1255:from 1942 onwards. 1091:Operation Sea Lion 1071:RAF Bentley Priory 806:F. W. Winterbotham 789:Army and Air Force 757: 668:W. T. "Bill" Tutte 513: 505: 452:Bernard Montgomery 417:F. W. Winterbotham 361:human intelligence 5285: 5284: 5088:Strategic Command 4756:978-0-19-280132-6 4734:978-0-297-78717-4 4675:The Red Orchestra 4623:978-0-330-41929-1 4578:978-0-911333-91-6 4556:978-0-14-193886-8 4536:978-0-89093-547-7 4415:978-0-14-139042-0 4406:Ultra goes to War 4393:978-0-89093-547-7 4326:978-0-684-83130-5 4284:978-0-241-89746-1 4225:978-0-521-44304-3 4195:978-0-19-280132-6 4160:978-1-84354-331-2 4142:978-0-415-36194-1 4103:978-0-330-23446-7 4073:Deutsch, Harold C 4029:Copeland, B. Jack 4003:978-0-14-144173-3 3982:978-0-947712-41-9 3937:978-0-684-85932-3 3889:Bertrand, Gustave 3766:Winterbotham 1974 3717:www.jewishgen.org 3589:Winterbotham 1974 3513:Winterbotham 1974 3311:, pp. 86–91. 3309:Winterbotham 1974 3285:Winterbotham 1974 3199:978-0-316-35253-6 3161:Winterbotham 1974 3051:Winterbotham 1974 2991:Winterbotham 1974 2941:Calvocoressi 2001 2895:, pp. 60–61. 2893:Winterbotham 1974 2883:, pp. 56–58. 2881:Winterbotham 1974 2845:Calvocoressi 2001 2823:, pp. 27–31. 2821:Winterbotham 1974 2726:Los Angeles Times 2645:Calvocoressi 2001 2584:, pp. 61–67. 2463:, pp. 81–92. 2325:Winterbotham 1974 2241:, pp. 11–13. 2222:Winterbotham 1974 2059:The Polish Review 1915:Project ARTICHOKE 1893:off the coast of 1767:National Archives 1685:Bitwa o tajemnice 1596:Manhattan Project 1567:centimetric radar 1497:Effect on the war 1357:Normandy landings 1122:Operation Compass 1115:10 Downing Street 1059:Battle of Britain 845:P H Lyon Playfair 833:General Lord Gort 716:stepping switches 616:, chief engineer 473:direction finding 425:Sir Harry Hinsley 401:Winston Churchill 260:Part of Japanese 213: 212: 5335: 4962:RAF Intelligence 4836:Security Service 4811: 4804: 4797: 4788: 4787: 4780: 4768:The Ultra Secret 4759: 4737: 4711: 4693:Welchman, Gordon 4688: 4669: 4645: 4626: 4604: 4581: 4560: 4539: 4515:Rejewski, Marian 4497:Rejewski, Marian 4493: 4467: 4466: 4464: 4445: 4418: 4396: 4368: 4345: 4338:The Ultra Secret 4329: 4308: 4287: 4264: 4251: 4250: 4248: 4243: 4228: 4207: 4198: 4177: 4175: 4163: 4145: 4127: 4126: 4124: 4119: 4106: 4090:Farago, Ladislas 4085: 4083: 4068: 4049: 4020: 4006: 3985: 3973:Top Secret Ultra 3964: 3962: 3960: 3948:(24 July 2005). 3940: 3917: 3896: 3884: 3866: 3834: 3833: 3815: 3809: 3808: 3790: 3784: 3778: 3769: 3763: 3757: 3756:, pp. 66–67 3754:Schlesinger 1992 3751: 3745: 3739: 3733: 3731:Riegner Telegram 3727: 3721: 3720: 3709: 3703: 3697: 3691: 3690: 3688: 3686: 3677:. Archived from 3671: 3665: 3658: 3652: 3646: 3640: 3634: 3628: 3622: 3616: 3610: 3604: 3598: 3592: 3586: 3580: 3574: 3568: 3567: 3556: 3550: 3545: 3537: 3531: 3530: 3522: 3516: 3510: 3504: 3503: 3501: 3499: 3484: 3478: 3477: 3471: 3466: 3464: 3456: 3454: 3452: 3446: 3439: 3430: 3424: 3418: 3412: 3411: 3409: 3407: 3393: 3387: 3381: 3375: 3369: 3363: 3357: 3351: 3345: 3339: 3338: 3337: 3335: 3326:, archived from 3318: 3312: 3306: 3300: 3294: 3288: 3282: 3276: 3270: 3264: 3258: 3252: 3246: 3240: 3234: 3228: 3222: 3216: 3210: 3204: 3203: 3185: 3176: 3170: 3164: 3158: 3152: 3151: 3133: 3127: 3121: 3115: 3109: 3103: 3097: 3091: 3085: 3079: 3078: 3063: 3054: 3048: 3042: 3036: 3030: 3024: 3018: 3012: 3006: 3000: 2994: 2988: 2982: 2976: 2970: 2969: 2967: 2965: 2960:on 29 April 2011 2950: 2944: 2938: 2932: 2926: 2920: 2914: 2908: 2902: 2896: 2890: 2884: 2878: 2872: 2866: 2860: 2854: 2848: 2842: 2836: 2830: 2824: 2818: 2812: 2806: 2800: 2794: 2788: 2787: 2785: 2783: 2778:on 29 April 2011 2774:. Archived from 2768: 2762: 2756: 2750: 2744: 2738: 2737: 2735: 2733: 2717: 2711: 2705: 2699: 2693: 2684: 2678: 2672: 2666: 2660: 2654: 2648: 2642: 2636: 2630: 2624: 2618: 2612: 2606: 2597: 2591: 2585: 2579: 2573: 2567: 2552: 2545: 2539: 2533: 2527: 2521: 2515: 2509: 2503: 2497: 2488: 2482: 2476: 2470: 2464: 2458: 2452: 2446: 2440: 2434: 2428: 2427: 2393: 2378: 2377: 2375: 2373: 2358: 2352: 2346: 2340: 2334: 2328: 2322: 2316: 2315: 2292: 2283: 2282: 2276: 2268: 2260: 2254: 2248: 2242: 2236: 2225: 2219: 2213: 2212: 2203: 2197: 2196: 2176: 2170: 2169: 2149: 2143: 2142: 2130: 2124: 2118: 2112: 2106: 2087: 2042: 2036: 2033: 2027: 2016: 2010: 1991: 1985: 1974: 1881:wartime partners 1816:Einsatz Reinhard 1735:The Ultra Secret 1728:Gustave Bertrand 1693:The Codebreakers 1633:The Ultra Secret 1516: 1408:Frederick Taylor 1369: 1334: 1242:Battle of Midway 1224: 1214: 1205: 1169: 1088: 1078: 1063:Sir Hugh Dowding 1044: 1035: 1022:Battle of France 990:Battle of France 857:Security Service 831:(BEF) headed by 600: 469:traffic analysis 338:. Several other 286: 257: 240: 223: 205: 198: 191: 33: 21: 20: 5343: 5342: 5338: 5337: 5336: 5334: 5333: 5332: 5288: 5287: 5286: 5281: 5244:No. 30 Commando 5143: 5137: 5110: 5104: 5032: 5026: 5006: 4999: 4978: 4971: 4918: 4911: 4897: 4890: 4827: 4820: 4815: 4785: 4778: 4757: 4735: 4709: 4685: 4667: 4642: 4624: 4602: 4579: 4557: 4537: 4505:Henryk Zygalski 4483: 4462: 4460: 4435: 4416: 4394: 4366: 4327: 4306: 4285: 4274:Most Secret War 4246: 4244: 4241: 4226: 4196: 4173: 4161: 4143: 4122: 4120: 4117: 4104: 4081: 4065: 4047: 4004: 3983: 3958: 3956: 3954:Washington Post 3938: 3915: 3901:Beesly, Patrick 3882: 3864: 3853:Body of Secrets 3842: 3837: 3830: 3816: 3812: 3805: 3791: 3787: 3779: 3772: 3764: 3760: 3752: 3748: 3740: 3736: 3728: 3724: 3711: 3710: 3706: 3698: 3694: 3684: 3682: 3673: 3672: 3668: 3659: 3655: 3647: 3643: 3635: 3631: 3623: 3619: 3611: 3607: 3599: 3595: 3587: 3583: 3575: 3571: 3557: 3553: 3538: 3534: 3523: 3519: 3511: 3507: 3497: 3495: 3485: 3481: 3469: 3467: 3458: 3457: 3450: 3448: 3444: 3437: 3431: 3427: 3419: 3415: 3405: 3403: 3395: 3394: 3390: 3382: 3378: 3370: 3366: 3358: 3354: 3346: 3342: 3333: 3331: 3330:on 2 April 2013 3320: 3319: 3315: 3307: 3303: 3295: 3291: 3283: 3279: 3271: 3267: 3259: 3255: 3247: 3243: 3235: 3231: 3223: 3219: 3211: 3207: 3200: 3186: 3179: 3171: 3167: 3159: 3155: 3148: 3134: 3130: 3122: 3118: 3110: 3106: 3098: 3094: 3086: 3082: 3072:Military Review 3064: 3057: 3049: 3045: 3037: 3033: 3025: 3021: 3013: 3009: 3001: 2997: 2989: 2985: 2977: 2973: 2963: 2961: 2952: 2951: 2947: 2939: 2935: 2927: 2923: 2915: 2911: 2903: 2899: 2891: 2887: 2879: 2875: 2867: 2863: 2855: 2851: 2843: 2839: 2831: 2827: 2819: 2815: 2807: 2803: 2795: 2791: 2781: 2779: 2770: 2769: 2765: 2757: 2753: 2745: 2741: 2731: 2729: 2718: 2714: 2706: 2702: 2694: 2687: 2679: 2675: 2667: 2663: 2657:Stephenson 2004 2655: 2651: 2643: 2639: 2631: 2627: 2619: 2615: 2607: 2600: 2592: 2588: 2580: 2576: 2568: 2555: 2549:Brzezinski 2005 2546: 2542: 2534: 2530: 2522: 2518: 2510: 2506: 2498: 2491: 2483: 2479: 2471: 2467: 2459: 2455: 2447: 2443: 2435: 2431: 2416:10.1145/3018994 2394: 2381: 2371: 2369: 2360: 2359: 2355: 2347: 2343: 2335: 2331: 2323: 2319: 2312: 2293: 2286: 2270: 2269: 2261: 2257: 2249: 2245: 2237: 2228: 2220: 2216: 2206: 2204: 2200: 2193: 2177: 2173: 2166: 2150: 2146: 2131: 2127: 2119: 2115: 2107: 2100: 2096: 2091: 2090: 2083:Daily Telegraph 2043: 2039: 2034: 2030: 2017: 2013: 1992: 1988: 1975: 1971: 1966: 1927: 1919:Project MKUltra 1903:John Chatterton 1873:John Cairncross 1836: 1777:Historians and 1775: 1712:Ladislas Farago 1677: 1617: 1517: 1514: 1499: 1471: 1418: 1383:Operation Cobra 1366:Panzergrenadier 1278:Operation Torch 1262:victory at the 1140:Battle of Crete 959: 943:John Cairncross 935:Rudolf Roessler 927:"Lucy" spy ring 923: 889:Buckinghamshire 877: 853: 791: 749: 704: 690:cipher machine 684: 647:Lorenz SZ 40/42 632: 626: 601: 599:Gordon Welchman 598: 587:Gordon Welchman 575:Marian Rejewski 524: 518: 497: 465: 442:. For example, 409:Stewart Menzies 394:Hagelin machine 386:Enigma decrypts 279: 277: 276: 275: 274: 272: 270: 266: 265: 264: 258: 249: 248: 247: 241: 232: 231: 230: 224: 209: 180: 162: 99:Zygalski sheets 59:Breaking Enigma 53: 17: 12: 11: 5: 5341: 5331: 5330: 5325: 5323:Bletchley Park 5320: 5315: 5310: 5305: 5300: 5283: 5282: 5280: 5279: 5274: 5269: 5264: 5259: 5254: 5248: 5247: 5246: 5241: 5231: 5226: 5225: 5224: 5219: 5214: 5211: 5206: 5201: 5198: 5193: 5188: 5183: 5178: 5173: 5168: 5163: 5158: 5147: 5145: 5139: 5138: 5136: 5135: 5130: 5125: 5120: 5114: 5112: 5106: 5105: 5103: 5102: 5097: 5092: 5091: 5090: 5085: 5075: 5070: 5069: 5068: 5058: 5056:Cabinet Office 5053: 5048: 5043: 5036: 5034: 5028: 5027: 5025: 5024: 5018: 5011: 5009: 5001: 5000: 4998: 4997: 4996: 4995: 4983: 4981: 4973: 4972: 4970: 4969: 4964: 4959: 4954: 4953: 4952: 4942: 4941: 4940: 4935: 4923: 4921: 4913: 4912: 4910: 4909: 4902: 4900: 4892: 4891: 4889: 4888: 4887: 4886: 4881: 4876: 4863: 4858: 4852: 4846: 4845: 4844: 4832: 4830: 4822: 4821: 4814: 4813: 4806: 4799: 4791: 4784: 4783: 4776: 4760: 4755: 4738: 4733: 4717: 4708:0-14-00-5305-0 4707: 4689: 4683: 4670: 4665: 4646: 4640: 4627: 4622: 4610:Smith, Michael 4606: 4600: 4582: 4577: 4561: 4555: 4540: 4535: 4511: 4494: 4481: 4468: 4446: 4433: 4420: 4414: 4398: 4392: 4381:W kręgu enigmy 4369: 4364: 4346: 4330: 4325: 4309: 4304: 4288: 4283: 4265: 4253: 4233:Hinsley, F. H. 4229: 4224: 4212:Hinsley, F. H. 4208: 4199: 4194: 4182:Hinsley, F. H. 4178: 4164: 4159: 4146: 4141: 4128: 4108: 4102: 4086: 4069: 4063: 4050: 4045: 4025:Copeland, Jack 4021: 4007: 4002: 3986: 3981: 3965: 3942: 3936: 3930:, Free Press, 3918: 3913: 3897: 3885: 3880: 3867: 3862: 3848:Bamford, James 3843: 3841: 3838: 3836: 3835: 3828: 3810: 3803: 3785: 3781:Knightley 1986 3770: 3758: 3746: 3734: 3722: 3704: 3692: 3666: 3662:Science Museum 3653: 3641: 3639:, p. 359. 3629: 3627:, p. 674. 3617: 3615:, p. 664. 3605: 3603:, p. 506. 3593: 3581: 3569: 3551: 3532: 3517: 3505: 3487:Hinsley, F.H. 3479: 3470:|journal= 3425: 3413: 3388: 3376: 3374:, p. 165. 3364: 3352: 3340: 3313: 3301: 3299:, p. 202. 3289: 3287:, p. 180. 3277: 3265: 3263:, p. 315. 3261:Budiansky 2000 3253: 3251:, p. 292. 3241: 3229: 3217: 3215:, p. 278. 3205: 3198: 3177: 3175:, p. 319. 3173:Budiansky 2000 3165: 3153: 3146: 3128: 3126:, p. 336. 3116: 3114:, p. 237. 3104: 3100:Budiansky 2000 3092: 3090:, p. 129. 3080: 3055: 3053:, p. 187. 3043: 3041:, p. 210. 3031: 3029:, p. 341. 3027:Budiansky 2000 3019: 3017:, p. 529. 3015:Churchill 2005 3007: 3005:, p. 104. 2995: 2983: 2971: 2945: 2933: 2921: 2909: 2897: 2885: 2873: 2871:, p. 124. 2861: 2849: 2837: 2825: 2813: 2811:, p. 301. 2809:Budiansky 2000 2801: 2789: 2763: 2761:, p. 170. 2751: 2739: 2712: 2710:, p. 142. 2700: 2685: 2683:, p. 152. 2673: 2671:, p. 138. 2661: 2649: 2647:, pp. 78. 2637: 2635:, p. 162. 2625: 2613: 2611:, p. 136. 2598: 2596:, p. 302. 2586: 2582:Wilkinson 1993 2574: 2553: 2540: 2528: 2526:, p. 103. 2516: 2504: 2502:, p. 289. 2489: 2477: 2465: 2453: 2441: 2439:, p. 145. 2429: 2379: 2353: 2351:, p. 297. 2341: 2329: 2317: 2310: 2284: 2255: 2243: 2226: 2214: 2198: 2191: 2171: 2164: 2144: 2125: 2113: 2097: 2095: 2092: 2089: 2088: 2037: 2028: 2011: 1986: 1968: 1967: 1965: 1962: 1961: 1960: 1953: 1948: 1943: 1938: 1933: 1926: 1923: 1835: 1832: 1820:Höfle telegram 1774: 1771: 1758:Bletchley Park 1750:Science Museum 1748:A 2012 London 1676: 1673: 1629:New York Times 1616: 1613: 1598:to create the 1571:conning towers 1512: 1498: 1495: 1479:Arlington Hall 1470: 1467: 1417: 1414: 1413: 1412: 1397: 1393: 1386: 1379: 1360: 1345: 1336: 1314: 1307: 1300: 1293:Doolittle Raid 1289:Balalae Island 1281: 1274: 1267: 1256: 1245: 1234: 1207: 1198: 1179: 1154: 1143: 1136: 1135:in March 1941. 1129: 1118: 1103:Coventry Blitz 1098: 1094: 1081: 1055: 1047:Dr R. V. Jones 1025: 958: 955: 947:Alexander Radó 922: 919: 876: 873: 852: 849: 790: 787: 769:Bletchley Park 748: 745: 730:Heer/Luftwaffe 703: 700: 696:Bletchley Park 683: 680: 628:Main article: 625: 622: 610:Hugh Alexander 596: 520:Main article: 517: 514: 496: 493: 485:radio networks 464: 461: 444:Andrew Roberts 405:King George VI 382:Enigma machine 345:The code name 316:Bletchley Park 268: 267: 262:PURPLE machine 259: 252: 251: 250: 242: 235: 234: 233: 227:Enigma machine 225: 218: 217: 216: 215: 214: 211: 210: 208: 207: 200: 193: 185: 182: 181: 179: 178: 172: 169: 168: 164: 163: 161: 160: 155: 150: 149: 148: 143: 138: 133: 128: 123: 118: 113: 106:Bletchley Park 103: 102: 101: 96: 91: 86: 81: 76: 65: 62: 61: 55: 54: 52: 51: 45: 42: 41: 39:Enigma machine 35: 34: 26: 25: 15: 9: 6: 4: 3: 2: 5340: 5329: 5326: 5324: 5321: 5319: 5316: 5314: 5311: 5309: 5306: 5304: 5301: 5299: 5296: 5295: 5293: 5278: 5275: 5273: 5270: 5268: 5265: 5263: 5260: 5258: 5255: 5252: 5249: 5245: 5242: 5240: 5237: 5236: 5235: 5232: 5230: 5227: 5223: 5220: 5218: 5215: 5212: 5210: 5207: 5205: 5202: 5199: 5197: 5194: 5192: 5189: 5187: 5184: 5182: 5179: 5177: 5174: 5172: 5169: 5167: 5164: 5162: 5159: 5157: 5154: 5153: 5152: 5149: 5148: 5146: 5140: 5134: 5131: 5129: 5126: 5124: 5121: 5119: 5116: 5115: 5113: 5107: 5101: 5098: 5096: 5093: 5089: 5086: 5084: 5081: 5080: 5079: 5076: 5074: 5071: 5067: 5064: 5063: 5062: 5059: 5057: 5054: 5052: 5049: 5047: 5044: 5041: 5038: 5037: 5035: 5029: 5022: 5019: 5016: 5013: 5012: 5010: 5008: 5002: 4994: 4991: 4990: 4988: 4985: 4984: 4982: 4980: 4974: 4968: 4965: 4963: 4960: 4958: 4955: 4951: 4948: 4947: 4946: 4943: 4939: 4936: 4934: 4931: 4930: 4928: 4925: 4924: 4922: 4920: 4914: 4907: 4904: 4903: 4901: 4899: 4893: 4885: 4882: 4880: 4877: 4875: 4872: 4871: 4870: 4867: 4864: 4862: 4859: 4856: 4853: 4850: 4847: 4843: 4840: 4839: 4837: 4834: 4833: 4831: 4829: 4823: 4819: 4812: 4807: 4805: 4800: 4798: 4793: 4792: 4789: 4782:inaccuracies. 4779: 4777:0-06-014678-8 4773: 4769: 4765: 4761: 4758: 4752: 4748: 4744: 4743:Hinsley, F.H. 4739: 4736: 4730: 4726: 4722: 4718: 4715: 4710: 4704: 4700: 4699: 4694: 4690: 4686: 4680: 4676: 4671: 4668: 4666:0-7475-7084-1 4662: 4658: 4654: 4653: 4647: 4643: 4641:1-84176-693-3 4637: 4633: 4628: 4625: 4619: 4615: 4611: 4607: 4603: 4601:1-85702-879-1 4597: 4593: 4592: 4587: 4583: 4580: 4574: 4570: 4566: 4562: 4558: 4552: 4548: 4547: 4541: 4538: 4532: 4528: 4524: 4520: 4516: 4512: 4510: 4509:Kozaczuk 1984 4506: 4502: 4501:Jerzy Różycki 4498: 4495: 4492: 4488: 4484: 4482:1-84375-252-2 4478: 4474: 4469: 4458: 4454: 4453: 4447: 4444: 4440: 4436: 4434:0-7110-2888-5 4430: 4426: 4421: 4417: 4411: 4407: 4403: 4402:Lewin, Ronald 4399: 4395: 4389: 4385: 4382: 4378: 4374: 4370: 4367: 4365:0-393-02386-9 4361: 4357: 4356: 4351: 4347: 4343: 4339: 4335: 4331: 4328: 4322: 4318: 4314: 4310: 4307: 4305:0-02-560460-0 4301: 4297: 4293: 4289: 4286: 4280: 4276: 4275: 4270: 4266: 4262: 4258: 4254: 4240: 4239: 4234: 4230: 4227: 4221: 4217: 4213: 4209: 4205: 4200: 4197: 4191: 4187: 4183: 4179: 4172: 4171: 4165: 4162: 4156: 4152: 4147: 4144: 4138: 4134: 4129: 4116: 4115: 4109: 4105: 4099: 4096:, Pan Books, 4095: 4091: 4087: 4080: 4079: 4074: 4070: 4066: 4064:9781780962436 4060: 4056: 4051: 4048: 4046:0-19-825080-0 4042: 4038: 4034: 4030: 4026: 4022: 4019: 4015: 4014: 4008: 4005: 3999: 3995: 3991: 3987: 3984: 3978: 3974: 3970: 3966: 3955: 3951: 3947: 3943: 3939: 3933: 3929: 3928: 3923: 3919: 3916: 3914:0-7221-1539-3 3910: 3906: 3902: 3898: 3894: 3890: 3886: 3883: 3881:0-7126-6521-8 3877: 3873: 3868: 3865: 3863:0-385-49907-8 3859: 3856:, Doubleday, 3855: 3854: 3849: 3845: 3844: 3831: 3829:9781538728031 3825: 3821: 3814: 3806: 3804:9781440858116 3800: 3796: 3789: 3782: 3777: 3775: 3768:, p. 25. 3767: 3762: 3755: 3750: 3744:, p. 124 3743: 3738: 3732: 3726: 3718: 3714: 3708: 3702:, p. 126 3701: 3696: 3680: 3676: 3670: 3663: 3657: 3650: 3649:Bertrand 1973 3645: 3638: 3633: 3626: 3621: 3614: 3609: 3602: 3597: 3590: 3585: 3578: 3573: 3565: 3561: 3555: 3548: 3543: 3536: 3528: 3521: 3514: 3509: 3494: 3490: 3483: 3475: 3462: 3443: 3436: 3429: 3422: 3417: 3402: 3398: 3392: 3385: 3380: 3373: 3368: 3361: 3356: 3349: 3344: 3329: 3325: 3324: 3317: 3310: 3305: 3298: 3293: 3286: 3281: 3275:, p. 40. 3274: 3269: 3262: 3257: 3250: 3245: 3239:, p. 39. 3238: 3233: 3226: 3221: 3214: 3209: 3201: 3195: 3191: 3184: 3182: 3174: 3169: 3162: 3157: 3149: 3147:9780253031433 3143: 3139: 3132: 3125: 3120: 3113: 3108: 3101: 3096: 3089: 3084: 3077: 3073: 3069: 3062: 3060: 3052: 3047: 3040: 3035: 3028: 3023: 3016: 3011: 3004: 2999: 2992: 2987: 2980: 2975: 2959: 2955: 2949: 2943:, p. 94. 2942: 2937: 2931:, p. 64. 2930: 2925: 2918: 2913: 2906: 2901: 2894: 2889: 2882: 2877: 2870: 2865: 2859:, p. 83. 2858: 2853: 2847:, p. 90. 2846: 2841: 2835:, p. 92. 2834: 2829: 2822: 2817: 2810: 2805: 2799:, p. 56. 2798: 2797:Welchman 1984 2793: 2777: 2773: 2767: 2760: 2755: 2748: 2743: 2728:(book review) 2727: 2723: 2716: 2709: 2704: 2697: 2692: 2690: 2682: 2677: 2670: 2665: 2659:, p. 56. 2658: 2653: 2646: 2641: 2634: 2629: 2623:, p. 36. 2622: 2617: 2610: 2605: 2603: 2595: 2590: 2583: 2578: 2571: 2570:Hinsley 1993a 2566: 2564: 2562: 2560: 2558: 2551:, p. 18) 2550: 2544: 2537: 2536:Hinsley 1993a 2532: 2525: 2520: 2514:, p. 17. 2513: 2508: 2501: 2500:Welchman 1984 2496: 2494: 2486: 2485:Copeland 2004 2481: 2474: 2473:Rejewski 1984 2469: 2462: 2461:Kozaczuk 1984 2457: 2450: 2449:Copeland 2004 2445: 2438: 2433: 2425: 2421: 2417: 2413: 2409: 2405: 2404: 2399: 2392: 2390: 2388: 2386: 2384: 2367: 2363: 2357: 2350: 2345: 2338: 2333: 2326: 2321: 2313: 2311:9780195113907 2307: 2303: 2302: 2297: 2291: 2289: 2280: 2274: 2266: 2259: 2252: 2247: 2240: 2235: 2233: 2231: 2223: 2218: 2211: 2210: 2202: 2194: 2192:9780684859323 2188: 2184: 2183: 2175: 2167: 2165:9781849542623 2161: 2157: 2156: 2148: 2140: 2136: 2129: 2123:, p. 64. 2122: 2117: 2111:, p. xx. 2110: 2105: 2103: 2098: 2085: 2084: 2079: 2075: 2071: 2070: 2065: 2061: 2060: 2055: 2051: 2046: 2041: 2032: 2025: 2021: 2015: 2008: 2004: 2000: 1996: 1990: 1983: 1979: 1973: 1969: 1959: 1958: 1954: 1952: 1949: 1947: 1944: 1942: 1939: 1937: 1934: 1932: 1929: 1928: 1922: 1920: 1916: 1911: 1908: 1904: 1900: 1899:Richie Kohler 1896: 1892: 1891: 1884: 1882: 1878: 1877:Anthony Blunt 1874: 1870: 1866: 1862: 1858: 1854: 1852: 1848: 1844: 1840: 1831: 1829: 1825: 1821: 1817: 1813: 1809: 1805: 1801: 1797: 1792: 1790: 1785: 1780: 1770: 1768: 1764: 1759: 1755: 1751: 1746: 1744: 1738: 1736: 1731: 1729: 1725: 1720: 1717: 1713: 1708: 1703: 1701: 1700: 1695: 1694: 1688: 1686: 1682: 1672: 1668: 1666: 1661: 1657: 1655: 1651: 1647: 1641: 1638: 1634: 1630: 1626: 1621: 1612: 1610: 1605: 1601: 1597: 1593: 1589: 1588:Western Front 1584: 1581: 1577: 1572: 1568: 1564: 1559: 1557: 1551: 1548: 1545: 1541: 1537: 1533: 1529: 1526: 1522: 1511: 1506: 1504: 1494: 1492: 1488: 1480: 1475: 1466: 1463: 1461: 1460: 1455: 1454:Caribbean Sea 1451: 1446: 1442: 1439: 1434: 1430: 1428: 1422: 1409: 1405: 1401: 1398: 1394: 1391: 1387: 1384: 1380: 1377: 1373: 1368: 1367: 1361: 1358: 1354: 1350: 1346: 1343: 1337: 1333: 1332: 1326: 1325: 1319: 1315: 1312: 1308: 1305: 1301: 1298: 1294: 1290: 1286: 1282: 1279: 1275: 1272: 1268: 1265: 1261: 1257: 1254: 1250: 1246: 1244:in June 1942. 1243: 1239: 1235: 1232: 1228: 1227:double agents 1223: 1218: 1213: 1208: 1204: 1199: 1196: 1192: 1188: 1184: 1180: 1177: 1173: 1168: 1163: 1159: 1155: 1152: 1148: 1144: 1141: 1137: 1134: 1130: 1127: 1123: 1119: 1116: 1112: 1111:Ditchley Park 1108: 1104: 1099: 1095: 1092: 1087: 1082: 1077: 1072: 1068: 1064: 1060: 1056: 1053: 1048: 1043: 1039: 1034: 1032: 1026: 1023: 1020:prior to the 1019: 1018:Low Countries 1015: 1014: 1013: 1010: 1007: 1003: 999: 994: 991: 987: 983: 978: 976: 975: 969: 963: 954: 952: 951:Harry Hinsley 948: 944: 940: 939:cryptanalysis 936: 932: 928: 918: 915: 913: 909: 904: 901: 897: 892: 890: 886: 882: 872: 870: 866: 862: 858: 848: 846: 842: 838: 834: 830: 824: 822: 818: 814: 809: 807: 804: 803:Group Captain 800: 795: 786: 783: 781: 777: 772: 770: 766: 762: 753: 744: 742: 738: 733: 731: 727: 726: 721: 717: 713: 709: 699: 697: 693: 689: 679: 677: 676:Tommy Flowers 673: 669: 663: 660: 656: 652: 648: 644: 640: 637: 636:stream cipher 631: 624:Lorenz cipher 621: 619: 615: 611: 607: 595: 590: 588: 584: 580: 576: 571: 569: 565: 561: 557: 553: 549: 545: 541: 537: 533: 529: 523: 509: 501: 492: 490: 486: 482: 478: 474: 470: 460: 458: 453: 449: 445: 441: 436: 434: 430: 426: 422: 418: 414: 411:(head of the 410: 406: 402: 397: 395: 391: 387: 383: 379: 374: 372: 368: 367: 362: 358: 354: 350: 349: 343: 341: 337: 333: 329: 325: 321: 317: 313: 309: 305: 301: 297: 293: 290: 284: 283: 263: 256: 245: 239: 228: 222: 206: 201: 199: 194: 192: 187: 186: 184: 183: 177: 174: 173: 171: 170: 166: 165: 159: 156: 154: 151: 147: 144: 142: 139: 137: 134: 132: 129: 127: 124: 122: 119: 117: 114: 112: 109: 108: 107: 104: 100: 97: 95: 92: 90: 87: 85: 82: 80: 77: 75: 72: 71: 70: 67: 66: 64: 63: 60: 57: 56: 50: 49:Enigma rotors 47: 46: 44: 43: 40: 37: 36: 32: 28: 27: 23: 22: 19: 5328:Cryptography 5033:Coordination 5005:Intelligence 4979:intelligence 4919:intelligence 4898:intelligence 4828:intelligence 4767: 4746: 4724: 4713: 4697: 4674: 4651: 4631: 4613: 4589: 4586:Singh, Simon 4568: 4545: 4526: 4472: 4461:, retrieved 4457:the original 4451: 4424: 4405: 4384: 4380: 4376: 4354: 4341: 4337: 4316: 4295: 4273: 4269:Jones, R. V. 4263:, p. 11 4260: 4245:, retrieved 4237: 4215: 4185: 4169: 4150: 4132: 4123:24 September 4121:, retrieved 4113: 4093: 4077: 4054: 4036: 4032: 4012: 3993: 3972: 3957:. Retrieved 3953: 3926: 3904: 3892: 3871: 3851: 3840:Bibliography 3819: 3813: 3794: 3788: 3761: 3749: 3737: 3725: 3716: 3707: 3695: 3683:. Retrieved 3679:the original 3669: 3656: 3644: 3632: 3620: 3608: 3596: 3591:, p. 1. 3584: 3579:, p. 5. 3572: 3563: 3560:Hartcup, Guy 3554: 3546: 3541: 3535: 3526: 3520: 3515:, p. 2. 3508: 3496:. Retrieved 3492: 3482: 3461:cite journal 3449:. Retrieved 3442:the original 3428: 3416: 3404:. Retrieved 3400: 3391: 3379: 3367: 3355: 3343: 3332:, retrieved 3328:the original 3322: 3316: 3304: 3292: 3280: 3268: 3256: 3244: 3232: 3220: 3208: 3189: 3168: 3156: 3137: 3131: 3119: 3107: 3095: 3083: 3075: 3046: 3034: 3022: 3010: 2998: 2986: 2981:, p. 3. 2979:Hinsley 1993 2974: 2962:. Retrieved 2958:the original 2948: 2936: 2929:Bennett 1999 2924: 2912: 2900: 2888: 2876: 2864: 2852: 2840: 2828: 2816: 2804: 2792: 2780:. Retrieved 2776:the original 2766: 2759:Tarrant 1995 2754: 2742: 2730:. Retrieved 2725: 2715: 2703: 2696:Pidgeon 2003 2676: 2664: 2652: 2640: 2628: 2616: 2594:Bennett 1999 2589: 2577: 2543: 2531: 2519: 2512:Bamford 2001 2507: 2480: 2468: 2456: 2444: 2432: 2410:(1): 29–35. 2407: 2401: 2370:. Retrieved 2366:the original 2356: 2349:Roberts 2009 2344: 2339:, p. 1. 2337:Deutsch 1977 2332: 2320: 2300: 2264: 2258: 2251:Hinsley 1996 2246: 2239:Hinsley 1993 2217: 2208: 2201: 2181: 2174: 2154: 2147: 2139:The Guardian 2138: 2128: 2116: 2081: 2078:Toby Harnden 2067: 2066:, author of 2064:Max Hastings 2057: 2053: 2040: 2031: 2019: 2014: 2006: 2002: 1998: 1994: 1989: 1972: 1955: 1912: 1906: 1889: 1885: 1859: 1855: 1846: 1841: 1837: 1800:Soviet Union 1793: 1776: 1747: 1743:Codebreakers 1742: 1739: 1734: 1732: 1723: 1721: 1715: 1710: 1705: 1698: 1691: 1689: 1684: 1683:in his book 1678: 1669: 1662: 1658: 1642: 1632: 1628: 1622: 1618: 1585: 1560: 1553: 1549: 1546: 1542: 1538: 1534: 1530: 1527: 1524: 1519: 1508: 1500: 1483: 1464: 1457: 1447: 1443: 1435: 1431: 1423: 1419: 1340: 1324:Duke of York 1323: 1260:Montgomery's 1106: 1011: 1001: 995: 979: 972: 964: 960: 924: 916: 912:one-time pad 905: 896:National HRO 893: 885:Whaddon Hall 878: 861:Herbert Hart 854: 825: 817:Air Ministry 810: 796: 792: 784: 773: 758: 747:Distribution 734: 729: 723: 705: 685: 664: 649:(Tunny) and 633: 612:and, at the 603: 592: 572: 525: 466: 457:Thomas Haigh 448:Erwin Rommel 437: 398: 376:Much of the 375: 364: 352: 347: 346: 344: 336:Ultra Secret 335: 331: 319: 281: 280: 278: 175: 18: 5061:Home Office 4721:West, Nigel 4463:18 February 4344:, p. 5 4334:Kahn, David 4313:Kahn, David 4292:Kahn, David 4257:Hunt, David 3742:Hanyok 2004 3700:Hanyok 2004 3685:8 September 3637:Farago 1974 3625:Farago 1974 3613:Farago 1974 3372:Ferris 2005 3348:Momsen 2007 3297:Taylor 2005 3273:Farley 1980 3237:Farley 1980 2964:16 December 2747:Crowdy 2011 2708:Beesly 1977 2621:Beesly 1977 2538:, p. 8 2524:Gannon 2006 2056:, 2005, in 1637:Third World 1609:Guy Hartcup 1600:atomic bomb 1563:Karl Dönitz 1547:Sincerely, 1450:Karl Dönitz 1331:Scharnhorst 1320:, in which 1193:to prevent 1172:"wolfpacks" 1057:During the 931:Switzerland 688:rotor-based 639:teleprinter 618:Harold Keen 606:Alan Turing 544:German Army 433:atomic bomb 332:Most Secret 330:then used ( 308:teleprinter 287:adopted by 116:Herivel tip 111:Banburismus 5292:Categories 5142:Historical 5109:Review and 5031:Policy and 5007:assessment 4684:0471134392 3451:14 January 3406:3 November 3334:9 February 3249:Lewin 2001 3225:Lewin 2001 3213:Lewin 2001 3124:Jones 1978 3112:Lewin 2001 3088:Smith 2007 3039:Lewin 2001 3003:Lewin 2001 2905:Jones 1978 2869:Jones 1978 2857:Lewin 2001 2833:Jones 1978 2437:Singh 1999 2372:25 January 2121:Lewin 2001 2094:References 1897:by divers 1895:New Jersey 1869:Kim Philby 1808:Jan Karski 1794:Following 1625:David Kahn 1602:. Author 1576:periscopes 1525:July 1945 1285:Yamamoto's 1249:Peenemünde 1191:Auchinleck 1097:cancelled. 1042:Knickebein 1031:KNICKEBEIN 813:War Office 672:Max Newman 568:Dilly Knox 556:Nazi party 540:Reichswehr 481:land lines 477:Phoney War 373:" cipher. 340:cryptonyms 89:Cyclometer 5111:Oversight 4695:(1984) , 4612:(2007) , 4443:181448256 4404:(2001) , 4315:(1997) , 4261:The Times 4235:(1996) , 4214:(1993a), 4092:(1974) , 3992:(2005) , 3971:(2001) , 3601:Kahn 1967 3577:Kahn 1974 3421:Kahn 1997 2917:Hunt 1976 2681:West 1986 2669:West 1986 2633:West 1986 2609:West 1986 2273:cite book 2020:Y Service 1861:Knightley 1754:centenary 1322:HMS 1203:Luftwaffe 1167:Luftwaffe 1086:Luftwaffe 1076:Luftwaffe 1002:Luftwaffe 968:indicator 914:systems. 869:St Albans 863:. In the 780:Admiralty 552:Air Force 489:Luftwaffe 300:encrypted 5144:agencies 4917:Military 4826:Domestic 4766:(1974), 4723:(1986), 4714:addendum 4588:(1999), 4491:56715513 4375:(1984), 4352:(1986), 4294:(1967), 4271:(1978), 4075:(1977), 3959:16 March 3924:(2000), 3903:(1977), 3891:(1973), 3850:(2001), 3562:(2000). 3549:, p. 26. 2424:41650745 2298:(1997). 1925:See also 1865:Cold War 1810:and the 1513:— 1459:B-Dienst 1195:Rommel's 1107:en route 982:PC Bruno 702:Japanese 659:Colossus 655:Sturgeon 597:— 577:and the 348:Boniface 153:PC Bruno 5239:Room 40 4989:(GCHQ) 4977:Signals 4896:Foreign 4247:23 July 4031:(ed.), 2074:C-SPAN2 2072:, in a 1847:postwar 1818:" (the 1665:V-E Day 1515:Hinsley 1390:Falaise 1181:In the 1162:U-boats 1080:source. 1024:in May. 903:SCU14. 900:Packard 708:Pacific 706:In the 682:Italian 589:wrote, 560:Gestapo 289:British 167:Related 74:Doubles 5023:(JTAC) 4857:(NBIS) 4838:(MI5) 4774: 4753: 4731: 4705: 4681: 4663: 4638: 4620: 4598: 4575: 4553: 4533: 4489: 4479: 4441: 4431: 4412: 4390: 4362: 4323: 4302: 4281: 4222: 4192: 4157: 4139: 4100: 4061: 4043: 4000: 3979: 3934: 3911: 3878: 3860: 3826: 3801: 3498:13 May 3196: 3144: 2782:8 July 2732:8 June 2422: 2308: 2189: 2162: 1978:PURPLE 1724:Enigma 1580:graphs 1536:them. 1438:Naples 1222:Abwehr 1212:Abwehr 1187:Wavell 1151:Stalin 1038:Cleves 1036:("The 998:bombes 815:, the 712:Purple 564:Abwehr 542:. The 528:Enigma 516:Enigma 495:German 378:German 371:Purple 324:Allies 302:enemy 5253:(SOE) 5042:(JIC) 5017:(JIO) 4929:(DI) 4908:(MI6) 4851:(NCA) 4242:(PDF) 4174:(PDF) 4118:(PDF) 4082:(PDF) 3729:See: 3445:(PDF) 3438:(PDF) 2420:S2CID 2205:see: 1982:JN-25 1964:Notes 1936:Hut 8 1931:Hut 6 1907:U-869 1890:U-869 1826:, an 1699:U-505 1427:Malta 1396:man". 1126:Libya 974:cribs 908:TYPEX 841:Meaux 776:Hut 8 765:Hut 6 737:JN-25 725:Magic 366:Magic 353:Ultra 320:Ultra 304:radio 282:Ultra 176:Ultra 158:Cadix 146:Hut 8 141:Hut 6 136:Hut 4 131:Hut 3 126:Bombe 94:Bomba 84:Clock 79:Grill 5222:MI19 5217:MI17 5213:MI16 5209:MI15 5204:MI14 5200:MI12 5196:MI11 5191:MI10 4772:ISBN 4751:ISBN 4729:ISBN 4703:ISBN 4679:ISBN 4661:ISBN 4636:ISBN 4618:ISBN 4596:ISBN 4573:ISBN 4551:ISBN 4531:ISBN 4503:and 4487:OCLC 4477:ISBN 4465:2008 4439:OCLC 4429:ISBN 4410:ISBN 4388:ISBN 4360:ISBN 4321:ISBN 4300:ISBN 4279:ISBN 4249:2012 4220:ISBN 4190:ISBN 4155:ISBN 4137:ISBN 4125:2016 4098:ISBN 4059:ISBN 4041:ISBN 4035:plus 3998:ISBN 3977:ISBN 3961:2016 3932:ISBN 3909:ISBN 3876:ISBN 3858:ISBN 3824:ISBN 3799:ISBN 3687:2015 3500:2020 3474:help 3453:2015 3408:2013 3336:2011 3194:ISBN 3142:ISBN 2966:2010 2784:2010 2734:2016 2374:2017 2306:ISBN 2279:link 2187:ISBN 2160:ISBN 1980:and 1901:and 1875:and 1851:GCHQ 1784:P.L. 1763:GCHQ 1654:KL-7 1646:NEMA 1189:and 921:Lucy 692:C-38 670:and 643:Fish 608:and 594:use. 548:Navy 471:and 306:and 121:Crib 5318:MI6 5186:MI9 5181:MI8 5176:MI7 5171:MI4 5166:MI3 5161:MI2 5156:MI1 4657:202 4340:", 2412:doi 1828:OSS 1812:WJC 1789:NSA 1737:. 1374:in 1217:MI5 1109:to 887:in 865:SIS 839:at 799:MI6 357:MI6 314:at 5294:: 4659:, 4521:; 4485:, 4437:, 4016:, 3952:. 3773:^ 3715:. 3491:. 3465:: 3463:}} 3459:{{ 3399:. 3180:^ 3070:. 3058:^ 2724:. 2688:^ 2601:^ 2556:^ 2492:^ 2418:. 2408:60 2406:. 2400:. 2382:^ 2287:^ 2275:}} 2271:{{ 2229:^ 2137:. 2101:^ 2052:, 1883:. 1871:, 1806:, 1295:, 977:. 871:. 819:, 698:. 678:. 558:, 554:, 550:, 546:, 435:. 396:. 318:. 4810:e 4803:t 4796:v 4687:. 4644:. 4559:. 4206:. 4067:. 3963:. 3832:. 3807:. 3719:. 3689:. 3664:. 3651:. 3547:2 3502:. 3476:) 3472:( 3455:. 3423:. 3410:. 3362:. 3350:. 3202:. 3150:. 2968:. 2919:. 2786:. 2736:. 2698:. 2572:. 2547:( 2426:. 2414:: 2376:. 2327:. 2314:. 2281:) 2253:. 2141:. 1984:. 1782:( 1392:. 1385:. 1054:. 653:( 526:" 204:e 197:t 190:v

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Ultra (cryptography)

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