Ultra (cryptography)

819:. 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. 1485: 739:. 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 511: 1467:, 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 266: 232: 2020:, 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. 1576:. 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 592:, 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 1500:, 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 519: 249: 42: 1776:(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 763: 631:. 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. 1730:

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."

438:, 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 948:. 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 1189:. 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. 1864:(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." 1116:. 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 677:

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

577:(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 2012:« 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, 1617:

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

1678:, 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. 1531:

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.

2008:, 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; 676:

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

2016:: '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 1569:. 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. 1654:

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

470:, "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." 4792:

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.

964:, 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". 1920:

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.

782:) 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. 1867:

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.

956:, 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, 837:

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

1833:), 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, 1792:

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

1473:, 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. 960:) 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, 834:, 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. 4601: 1542:

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

395:. 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 " 1406:

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.

725:" 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 1463:

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.

1813:, 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 1878:. 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 1572:

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.

1181:. 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 3689: 2733:"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)" 2372: 442:

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

902:, 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. 697:

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

1856:, 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 5308: 4967: 4510:, 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, 1436:

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

1417:, 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 1270: 5161: 1601:

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

4528:(1984), "Summary of Our Methods for Reconstructing ENIGMA and Reconstructing Daily Keys, and of German Efforts to Frustrate Those Methods: Appendix C", in 1027:

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

4123: 812:, 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 1744:

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

5313: 4819: 1171:. 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 4087: 337:

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.

5025: 2289: 1284:, 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. 1164:

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:

1185:, 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 5003: 1580:, developed in a joint British-American venture, which became operational in the spring of 1943. Earlier radar was unable to distinguish U-boat 5239: 1987:

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

668:). These cipher systems were cryptanalysed, particularly Tunny, which the British thoroughly penetrated. It was eventually attacked using 5110: 4906: 4894: 4836: 4022: 1186: 866:

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

4865: 1317:, decrypted by the SIS starting in July 1943, helped U.S. submarines and aircraft sink two-thirds of the Japanese merchant marine. 1634:

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.

4852: 4812: 1961: 1777: 846:. The first liaison officers were Robert Gore-Browne and Humphrey Plowden. A second SLU of the 1940 period was attached to the 743:

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

17: 4461: 5088: 1501: 3960: 1084:, for Ultra reports. Ultra intelligence kept him informed of German strategy, and of the strength and location of various 4955: 1056:

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

5098: 4943: 4871: 4717: 4620: 1314: 751: 640: 624: 549:

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

2164: 2073:, vol. L, no. 2, 2005, p. 241). A kindred point concerning postwar American triumphalism is made by British historian 1841:

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

5143: 4948: 4805: 4786: 4675: 4650: 4610: 4491: 4443: 4374: 4314: 4073: 4055: 4044:

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

3923: 3890: 3872: 3838: 3813: 3156: 2320: 2201: 2174: 1780:; the seven decades' delay had been due to their "continuing sensitivity... It wouldn't have been safe to release ." 1197: 1932:. MK was the CIA's designation for its Technical Services Division and Ultra was in reference to the Ultra project. 457:, writing in the 21st century, states, "Because he had the invaluable advantage of being able to read Field Marshal 2046:

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

1799: 1767:

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

5031: 4028: 3087:

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

1370:

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

1073: 847: 843: 620: 1217:

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

5318: 4693: 4408:

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

450: 371: 1004:

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

5138: 4828: 1341: 3904:

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

3407: 1860:

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

1399:

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

5261: 4181:

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

1838: 1698:("Battle for Secrets") first revealed Enigma had been broken by Polish cryptologists before World War II. 1602: 1598: 1418: 2968: 5282: 5267: 5105: 1281: 1016: 730: 615:

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

532: 423: 396: 206: 69: 2732: 2408: 2033:

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

1814: 454: 4388:

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

4328:

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

4307:

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

1353:

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

793:'s Operational Intelligence Centre (OIC), which distributed it initially under the codeword "HYDRO". 5093: 4884: 2413: 1834: 1809:, decrypts in August 1941 alerted British authorities to the many massacres in occupied zones of the 1444:

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

1321: 996: 4538:

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

4179: 3484: 1928:, a series of experiments on human subjects to develop drugs for use in interrogations, was renamed 1496:

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

381: 5272: 2065:

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

1916:

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

1660: 1263: 1160:, the German invasion of the USSR. Although this information was passed to the Soviet government, 5333: 5287: 5015: 4529: 4383: 4024:

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

3916:

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

3672: 1760: 1691: 1497: 1382: 1274: 1248: 1193: 1182: 554: 272: 4394:, Warsaw, Książka i Wiedza, 1979, supplemented with appendices by Marian Rejewski, Frederick, MD 1023:

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

4575: 3671:

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

3338: 1898: 1891: 1708: 1590: 1566: 1168: 1143: 984: 665: 439: 338: 334: 199: 131: 79: 2310: 502:

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

5338: 4927: 4879: 4859: 4279: 4267: 3471: 2786: 2060: 1956: 1822: 1513: 1332: 1057: 891: 593: 546: 404: 302: 754:

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

4987: 4937: 4533: 2306: 2055: 1951: 1806: 1614: 1328: 1157: 771: 735: 431: 410:

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

376: 306: 104: 94: 84: 59: 4667: 4661: 4578:(1992), "The London Operation: Recollections of a Historian", in Chalou, George C. (ed.), 1007:

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

652:

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

8: 5277: 4960: 4876: 4344: 4323: 4302: 1635: 1359: 1307: 1241: 1100:

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

1077: 1062: 978: 831: 746:

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

661: 653: 578: 3952:

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

1484: 4797: 4774: 4511: 3979: 3956: 2430: 2283: 2218: 2079: 1967: 1853: 1565:

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

1414: 1386: 1363: 1142:

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

1101: 1081: 816: 462: 427: 89: 4390:

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

909:, made in the USA. The SCUs were highly mobile and the first such units used civilian 4782: 4761: 4739: 4713: 4707: 4689: 4671: 4646: 4628: 4606: 4583: 4561: 4541: 4497: 4487: 4449: 4439: 4420: 4398: 4370: 4364: 4360: 4331: 4310: 4289: 4247: 4230: 4200: 4165: 4147: 4108: 4083: 4069: 4051: 4008: 4000: 3987: 3942: 3936: 3932: 3919: 3886: 3868: 3834: 3809: 3723: 3204: 3152: 2316: 2197: 2170: 2146:"The Imitation Game: how Alan Turing played dumb to fool US intelligence - David Cox" 2069: 1925: 1871: 1789: 1606: 1577: 1447:

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

1367: 1201: 1132: 1125: 1069: 790: 669: 483: 411: 4283: 2434: 1830: 1247:

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

957: 510: 4972: 3899: 3741: 2422: 2037:, after it was reassigned to MI6 and they were not involved in Ultra dissemination. 1826: 1738: 1703: 1295: 1252: 1032: 1000: 917:

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

855: 705:. This was broken from June 1941 onwards by the Italian subsection of GC&CS at 479: 4723:

An early publication containing several misapprehensions that are corrected in an

4467: 4213:

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

1674:

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

589: 5254: 4703: 4555: 4525: 4515: 4507: 4100: 3863: 3831:

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

3082: 3078: 2093: 1929: 1913: 1883: 1794: 1722: 1393: 1376: 1288: 1258:

Ultra contributed very significantly to the monitoring of German developments at

1150: 953: 945: 899: 766:

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

726: 597: 585: 419: 109: 4602:

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

4263:

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

3201:

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

2166:

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

1440:. In fact, there were only 25 submarines and at times as few as three aircraft. 1011:

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

5066: 4731: 3911: 3499: 1825:

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

1768: 1656: 1489: 1400: 1303: 1299: 1113: 779: 706: 538: 415: 392: 326: 299: 237: 116: 49: 3149:

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

1573: 1460: 952:

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

5302: 4753: 4627:, Pan Grand Strategy Series (Pan Books ed.), London: Pan MacMillan Ltd, 4453: 4243: 4222: 4192: 4039: 4035: 3858: 1909: 1887: 1581: 1464: 1410: 1237: 1161: 1028: 961: 949: 937: 871: 813: 718: 698: 686: 657: 646: 542: 495: 435: 434:, at war's end describing Ultra as having been "decisive" to Allied victory. 400: 254: 4501: 1259: 936:

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

5328: 4412: 2783:"Bletchley Park Archives: Government Code & Cypher School Card Indices" 2088: 2074: 1810: 1205: 922: 906: 895: 827: 808:

Dissemination of Ultra intelligence to field commanders was carried out by

558: 467: 458: 388: 126: 1112:

signals. Unfortunately, countermeasures failed to prevent the devastating

1044:

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

466:

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

5071: 4596: 3686:"Nazi War Crimes and Japanese Imperial Government Disclosure Act of 2000" 3570: 1647: 1619: 1610: 1287:

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

941: 722: 678: 649: 628: 616: 443: 318: 121: 1459:

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

265: 231: 27:

British designation for intelligence from decrypted enemy communications

1905: 1879: 1818: 1646:, after the war, surplus Enigmas and Enigma-like machines were sold to 1280:

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

1041: 823: 682: 596:

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

566: 550: 514:

A typical Bletchley intercept sheet, before decryption and translation.

487: 99: 4347:(29 December 1974), "Enigma Unwrapped: Review of F. W. Winterbotham's 486:. In the early phases of the war, particularly during the eight-month 1764: 1763:

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

1586: 879: 562: 499: 350: 4616:

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

4419:(Penguin Classic Military History ed.), London: Penguin Group, 2426: 1080:, had a teleprinter link from Bletchley Park to his headquarters at 518: 4540:(2 ed.), University Publications of America, pp. 241–45, 4463:

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

2004:

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

1875: 1874:

suggests that Ultra may have contributed to the development of the

1733:

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

1469: 1358:

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

1346:, was entirely built on prompt deciphering of German naval signals. 1121: 992: 762: 491: 163: 4484:

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

3938:

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

2995: 2193:

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

1741:

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

1663:(NSA) retired the last of its rotor-based encryption systems, the 5249: 4580:

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

2084: 1675: 1320:

The part played by Ultra intelligence in the preparation for the

1230:) had captured all of the German agents in Britain, and that the 995:

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

910: 570: 498:. German Enigma messages were the main source, with those of the 310: 4199:(OU Press paperback ed.), Oxford: Oxford University Press, 3787: 3785: 3437: 3334:

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

2409:"Colossal Genius: Tutte, Flowers, and a Bad Imitation of Turing" 1456:

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

977:

the callsign of the originating and receiving stations, and the

248: 3165: 2965:"Seventy Years Ago This Month at Bletchley Park: December 1940" 2226: 1988: 1448: 1172: 1167:

Ultra intelligence made a very significant contribution in the

1048: 894:, who from 1938 to 1946 was head of MI6 Section VIII, based at 858:. This SLU was commanded by Squadron Leader F.W. "Tubby" Long. 574: 573:

and German diplomats used Enigma machines in several variants.

4066:

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

3079:"The contribution of Intelligence at the Battle of Alam Halfa" 1251:

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

41: 3782: 3313: 2897: 2885: 2825: 2115: 2113: 1992: 1946: 1941: 1605:, and the completely independent development of the U.S.-led 1437: 1294:

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

1136: 1128:

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

1008: 918: 851: 786: 775: 747: 702: 333:

eventually became the standard designation among the western

314: 168: 156: 151: 146: 141: 136: 4187:, Center for Cryptographic History, National Security Agency 3885:(Pimlico: New and Enlarged ed.), London: Random House, 3364: 3104: 2489: 2453: 584:

German military Enigma was first broken in December 1932 by

5232: 5227: 5219: 5214: 5206: 5201: 4997: 4430:

Focuses on the battle-field exploitation of Ultra material.

4125:

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

3770: 3289: 3055: 2245: 2243: 2241: 1861: 1773: 1664: 1659:, and used it into the late 1970s, while the United States 1603:

Eastern Front conflict between Germany and the Soviet Union

4890:

National Domestic Extremism and Disorder Intelligence Unit

3593: 3577:. Basingstoke, Hampshire: Macmillan Press. pp. 96–99. 3395:

Sharing the Burden—Women in Cryptology During World War II

2945: 2849: 2649: 2586: 2506: 2504: 2477: 2110: 1718:

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

1707:

described the 1944 capture of a Naval Enigma machine from

490:, the Germans could transmit most of their messages using 399:". However, Ultra also encompassed decrypts of the German 5196: 5191: 5186: 5181: 5176: 5171: 5166: 4968:

1st Intelligence, Surveillance and Reconnaissance Brigade

4916: 4846: 4645:. Fortress. Vol. 16. Oxford, UK: Osprey Publishing. 3517: 2751: 2465: 2312:

A Century of Spies: Intelligence in the Twentieth Century

2034: 2010:

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

1227: 1226:

transmissions confirmed that Britain's Security Service (

1131:

Ultra intelligence considerably aided the British Army's

875: 867: 809: 367: 4827: 4330:(2nd Revised ed.), New York: Simon & Schuster, 3806:

Conspiracies and Conspiracy Theories in American History

3265: 3229: 3177: 3031: 3019: 2909: 2813: 2661: 2329: 2238: 581:

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

4752:

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

4557:

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

3883:

Behind the Battle: Intelligence in the War with Germany

3397:, Jennifer Wilcox, Center for Cryptologic History, 1998 2576: 2574: 2572: 2570: 2568: 2501: 2029:

In addition, there were SCU3 and SCU4, which supported

1479: 1156:

Ultra intelligence fully revealed the preparations for

1124:, was told that London might be bombed and returned to 890:

The communications system was founded by Brigadier Sir

645:

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

380:

for its decrypts from Japanese sources, including the "

3641: 3629: 3617: 2967:. Bletchley Park National Codes Centre. Archived from 2801: 2763: 2702: 2700: 2615: 2613: 2598: 2353: 2006:

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

878:

this intelligence was handled by "Section V" based at

770:

Army- and Air Force-related intelligence derived from

522:

A typical Bletchley intercept sheet, after decryption.

374:

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

3653: 3376: 3301: 2933: 2712: 2528: 2516: 1890:, may thus have felt still more distrustful of their 1310:, killing this man who was regarded as irreplaceable. 3808:. Santa Barbara, California: ABC-CLIO. p. 200. 3605: 3277: 3253: 3241: 3217: 3128: 3116: 3092: 3043: 3007: 2983: 2873: 2625: 2565: 2441: 2341: 1504:

to encourage women to stay at home and have babies.

4118:

Has been criticised for inaccuracy and exaggeration

4089:

The Historical Impact of Revealing the Ultra Secret

2861: 2837: 2697: 2685: 2673: 2637: 2610: 2255: 2014:

that were reported to me by General Menzies himself

1366:. They revealed the Germans did not anticipate the 1302:, and on 18 April, a year to the day following the 1211:Ultra intelligence from Hagelin decrypts, and from 403:that were used by the German High Command, and the 4095:, Parameters, Journal of the U.S. Army War College 3400: 3352: 2552: 2373:"Bletchley Park Welcomes 2015'S 200,000th Visitor" 2315:. New York: Oxford University Press. p. 296. 2125: 2018:"C": The Secret Life of Sir Stewart Graham Menzies 1897:The mystery surrounding the discovery of the sunk 5129:Intelligence and Security Committee of Parliament 4005:The Second World War, Volume 2: Their Finest Hour 3581: 1597:While Ultra certainly affected the course of the 1381:division in the planned dropping zone for the US 1208:forces from reaching Cairo in the autumn of 1941. 5309:Telecommunications-related introductions in 1941 5300: 4758:Codebreakers: The inside story of Bletchley Park 4433: 4197:Codebreakers: The inside story of Bletchley Park 3500:"The Influence of ULTRA in the Second World War" 3425: 3370: 2921: 2375:. Bletchley Park. 26 August 2015. Archived from 1277:by providing warning of Rommel's planned attack. 3833:(1st ed.). New York: Twelve. p. 264. 1488:Women cryptologists at work in the U.S. Army's 4582:, Washington, DC: Government Printing Office, 4249:The Influence of ULTRA in the Second World War 3804:Fee, Christopher R.; Webb, Jeffrey B. (2019). 2540: 5134:Independent Reviewer of Terrorism Legislation 4813: 4625:Station X: The Codebreakers of Bletchley Park 4486:, St Leonards-on-Sea, East Sussex: UPSO Ltd, 4214: 4191: 3575:The Effect of Science on the Second World War 3538:All Hell Let Loose: The World at War, 1939–45 2730: 2119: 1135:victory over the much larger Italian army in 656:. Several systems were used, principally the 430:quoted the western Supreme Allied Commander, 323:Government Code and Cypher School (GC&CS) 207: 5084:Foreign, Commonwealth and Development Office 4773: 4709:The Hut Six story: Breaking the Enigma codes 4227:British intelligence in the Second World War 3986:, Kidderminster, England: M & MBaldwin, 3978: 3776: 3599: 3523: 3319: 3295: 3171: 3061: 3001: 2951: 2903: 2891: 2855: 2831: 2655: 2335: 2301: 2299: 2288:: CS1 maint: multiple names: authors list ( 2232: 1374: 1339: 1231: 1221: 1212: 1176: 1095: 1085: 1051: 1039: 870:started "Special Research Unit B1(b)" under 721:theatre, a Japanese cipher machine, called " 4895:National Counter Terrorism Policing Network 4574: 3764: 1756:(1993), edited by Hinsley and Alan Stripp. 1315:Japanese Army’s "2468" water transport code 774:(SIGINT) sources—mainly Enigma decrypts in 541:" refers to a family of electro-mechanical 4978:30 Commando Information Exploitation Group 4820: 4806: 4640: 4270:(28 August 1976), "The raid on Coventry", 4162:Colossus: Bletchley Park's Greatest Secret 4144:Intelligence and strategy: selected essays 4007:(Penguin Classics ed.), p. 529, 3955: 3555:. London: Her Majesty's Stationery Office. 3451:. National Security Agency. Archived from 3072: 3070: 2667: 2559: 1426: 1244:. This enabled major deception operations. 1175:was much more difficult than those of the 473: 214: 200: 5314:1941 establishments in the United Kingdom 5077:Office for Security and Counter-Terrorism 4751: 4712:, Harmondsworth, England: Penguin Books, 4438:, Hersham, Surrey: Ian Allan Publishing, 4359: 4229:, Cambridge: Cambridge University Press, 3999: 3931: 3791: 3553:The U-Boat war in the Atlantic, 1939–1945 3446:"The Cryptographic Mathematics of Enigma" 3271: 3183: 3110: 3037: 3025: 2819: 2592: 2305: 2296: 2189: 1783: 885: 778:—was compiled in summaries at GC&CS ( 4866:National Ballistics Intelligence Service 4702: 4524: 4519: 4382: 4221: 4034: 3898: 3659: 3540:. London: HarperPress. pp. 275–276. 3535: 3194: 3192: 3151:. Indiana University Press. p. 95. 2807: 2580: 2546: 2510: 2495: 2483: 2471: 2459: 2402: 2400: 2398: 2396: 2394: 1483: 1139:between December 1940 and February 1941. 861: 761: 517: 509: 4683: 4553: 4481: 4242: 4212: 4082: 3880: 3857: 3803: 3569: 3563: 3550: 3067: 2989: 2939: 2769: 2731:Piekalkiewicz, Janusz (9 August 1987). 2706: 2604: 2522: 2359: 2347: 2261: 2249: 1844: 14: 5301: 4998:Government Communications Headquarters 4853:National Protective Security Authority 4736:GCHQ: The Secret Wireless War, 1900–86 4659: 4560:. Penguin Books Limited. p. 501. 4518:. Most of Rejewski's papers appear in 4459: 4397:, University Publications of America, 4177: 4159: 4141: 4121: 4099: 4063: 3910: 3752: 3710: 3647: 3635: 3623: 3443: 3382: 3358: 3307: 3283: 3247: 3146: 2757: 2718: 2631: 2534: 2273: 1962:Signals intelligence in modern history 1685: 1625: 967: 4801: 4643:The fortifications of Malta 1530–1945 4619: 4595: 4411: 4309:(1st ed.), New York: Macmillan, 4278: 4020: 3828: 3259: 3235: 3223: 3198: 3189: 3134: 3122: 3098: 3076: 3049: 3013: 2915: 2879: 2867: 2843: 2447: 2406: 2391: 2162: 2131: 1362:, the deception operation to protect 799: 353:had been used for such intelligence. 5324:Signals intelligence of World War II 5162:Directorate of Military Intelligence 4829:United Kingdom intelligence agencies 4730: 4343: 4322: 4301: 4266: 3611: 3587: 3431: 3077:Smith, Kevin D. (July–August 2002). 2927: 2691: 2679: 2643: 2619: 2080:Inferno: The World at War, 1939–1945 1507: 1502:Cross of Honour of the German Mother 1480:Role of women in Allied codebreaking 1373:Information that there was a German 944:and apparently operated by one man, 391:cipher traffic was encrypted on the 4760:, Oxford: Oxford University Press, 4738:, London: Weidenfeld and Nicolson, 4146:(illustrated ed.), Routledge, 4050:, Oxford: Oxford University Press, 3497: 2190:Budiansky, Stephen (27 June 2018). 2143: 1690:In 1967, Polish military historian 1038:An Ultra decrypt of June 1940 read 24: 4944:Defence Intelligence Fusion Centre 4872:National Fraud Intelligence Bureau 4122:Farley, R. D. (25 November 1980), 2220:Crypto AG: Hagelin cipher machines 2163:Smith, Michael (31 October 2011). 641:Cryptanalysis of the Lorenz cipher 625:British Tabulating Machine Company 547:polyalphabetic substitution cipher 461:'s Enigma communications, General 25: 5350: 5144:Investigatory Powers Commissioner 4949:Joint Intelligence Training Group 3724:"Poland and her Jews 1941 - 1944" 4663:Dresden:Tuesday 13 February 1945 4466:, Nautical Brass, archived from 4288:, London: Book Club Associates, 3822: 3797: 3758: 3746: 3734: 3716: 3704: 3678: 3665: 2049: 1551:eventually forced to surrender. 789:was forwarded from Hut 4 to the 634: 309:obtained by breaking high-level 264: 247: 230: 40: 5032:Joint Terrorism Analysis Centre 5026:Joint Intelligence Organisation 4434:Mallmann-Showell, J.P. (2003), 4029:Royal United Services Institute 3850: 3544: 3529: 3491: 3388: 3325: 3140: 2957: 2775: 2724: 2365: 2267: 2144:Cox, David (28 November 2014). 2040: 2023: 1737:by French intelligence officer 1240:which MI5 controlled under the 848:RAF Advanced Air Striking Force 757: 729:. It was broken by the US Army 345:) and so was regarded as being 5004:National Cyber Security Centre 4781:, New York: Harper & Row, 4666:, London: Bloomsbury, p. 3203:. New York, Boston: Hachette. 2407:Haigh, Thomas (January 2017). 2210: 2183: 2156: 2137: 1998: 1981: 1498:women worked at Bletchley Park 999:in April. At the start of the 854:commanded by Air Vice-Marshal 451:historiography of World War II 13: 1: 5240:Naval Intelligence Department 5139:Investigatory Powers Tribunal 4195:; Stripp, Alan, eds. (1993), 2104: 2087:"After WORDS" interview with 1313:Ship position reports in the 1149:Although the Allies lost the 1015:messages. By the peak of the 594:reconstructed Enigma machines 362:was used as a cover name for 5262:Special Operations Executive 5051:Joint Intelligence Committee 4641:Stephenson, Charles (2004). 4366:The Second Oldest Profession 4142:Ferris, John Robert (2005), 2278:. New York: Alfred A. Knopf. 2097:, broadcast 4 December 2011. 2059:their own wars." (Review of 1389:led to a change of location. 1196:, Ultra intelligence helped 282:were broken by the Allies to 7: 5283:Special Reconnaissance Unit 5268:Diplomatic Wireless Service 5245:Naval Intelligence Division 5106:Single Intelligence Account 4917:Secret Intelligence Service 4215:Hinsley & Stripp (1993) 3504:Keith Lockstone's home page 1935: 1338:sank the German battleship 1282:Second Battle of El Alamein 1236:still believed in the many 1094:Decryption of traffic from 1017:Battle of the Mediterranean 840:British Expeditionary Force 731:Signal Intelligence Service 712: 533:Cryptanalysis of the Enigma 424:Secret Intelligence Service 10: 5355: 5111:National Security Strategy 4482:Pidgeon, Geoffrey (2003), 4436:German Naval Code Breakers 4353:New York Times Book Review 4178:Hanyok, Robert J. (2004), 4164:, London: Atlantic Books, 2274:Keegan, John, Sir (2003). 2091:, U.S. editor of London's 1815:Polish government-in-exile 1772:Departmental Historian at 1392:Ultra assisted greatly in 1308:his aircraft was shot down 1104:to invade England in 1940. 921:cryptographic machine and 785:Naval Enigma decrypted in 692: 638: 530: 414:was reported to have told 280:Three cipher machines that 5152: 5119: 5094:Chiefs of Staff Committee 5062:National Security Adviser 5057:National Security Council 5041: 5014: 4986: 4926: 4905: 4885:Counter Terrorism Command 4835: 4660:Taylor, Fredrick (2005), 4605:, London: Fourth Estate, 4068:. Bloomsbury Publishing. 3551:Hessler, Günther (1989). 2414:Communications of the ACM 2206:– via Google Books. 2179:– via Google Books. 2120:Hinsley & Stripp 1993 1642:review of Winterbotham's 1322:Allied invasion of Sicily 997:Allied campaign in Norway 526: 505: 418:, when presenting to him 305:in June 1941 for wartime 35:The Enigma cipher machine 5273:Far East Combined Bureau 4554:Roberts, Andrew (2009). 4536:; Frederick, MD (eds.), 4369:, W.W. Norton & Co, 3918:, Sphere Books Limited, 3881:Bennett, Ralph (1999) , 1974: 1661:National Security Agency 1638:pointed out in his 1974 1264:V-1 and V-2 intelligence 1220:Ultra intelligence from 1076:, Commander-in-Chief of 685:and electrical engineer 401:Lorenz SZ 40/42 machines 284:yield Ultra intelligence 5288:Military Reaction Force 4756:; Stripp, Alan (eds.), 4576:Schlesinger, Arthur Jr. 3906:, Paris: Librairie Plon 3444:Miller, A. Ray (2001). 3412:Bletchley Park Research 2276:Intelligence in Warfare 2169:. Biteback Publishing. 1701:In 1967, David Kahn in 1514:end of the European war 1427:Safeguarding of sources 1383:101st Airborne Division 1291:) were not anticipated. 1275:Battle of Alam el Halfa 1249:Battle of the Coral Sea 1194:Western Desert Campaign 931: 805:control dissemination. 474:Sources of intelligence 339:security classification 4684:Tarrant, V.E. (1995). 4460:Momsen, Bill (2007) , 4064:Crowdy, Terry (2011). 3536:Hastings, Max (2011). 3479:Cite journal requires 3004:, pp. 67–69, 187. 2196:. Simon and Schuster. 2035:Radio Security Service 1899:German submarine 1784:Holocaust intelligence 1720: 1667:series, in the 1980s. 1567:Battle of the Atlantic 1563: 1539:Dear General Menzies: 1529: 1492: 1411:Arthur "Bomber" Harris 1375: 1355: 1340: 1262:and the collection of 1232: 1222: 1213: 1187:4-rotor Enigma machine 1177: 1169:Battle of the Atlantic 1144:Battle of Cape Matapan 1096: 1086: 1052: 1040: 886:Radio and cryptography 767: 613: 523: 515: 440:counterfactual history 321:communications at the 5319:Military intelligence 4880:Specialist Operations 4860:National Crime Agency 4534:Kasparek, Christopher 4160:Gannon, Paul (2006), 4048:The Secrets of Enigma 4038:(2004), "Enigma", in 3829:Brown, Brian (2019). 3371:Mallmann-Showell 2003 3147:Harper, Glyn (2017). 2307:Richelson, Jeffery T. 2061:Michael Alfred Peszke 1957:Military intelligence 1790:Holocaust researchers 1727:The Game of the Foxes 1715: 1534: 1518: 1487: 1413:, officer commanding 1350: 1298:forthcoming visit to 1269:Ultra contributed to 892:Richard Gambier-Parry 862:Intelligence agencies 765: 752:Japanese Army's codes 602: 543:rotor cipher machines 521: 513: 303:military intelligence 240:out of its wooden box 18:Boniface (cover name) 4938:Defence Intelligence 4727:in the 1997 edition. 4021:Comer, Tony (2021), 3961:"Giving Hitler Hell" 3408:"Women Codebreakers" 3199:Mundy, Liza (2017). 2498:, pp. 234, 235. 2462:, pp. 231, 232. 2235:, pp. 154, 191. 2056:Christopher Kasparek 1952:Magic (cryptography) 1845:Postwar consequences 1807:Operation Barbarossa 1725:'s 1971 best-seller 1615:Jeffrey T. Richelson 1561:Dwight D. Eisenhower 1329:Battle of North Cape 1158:Operation Barbarossa 1072:, Air Chief Marshal 772:signals intelligence 733:and disseminated as 590:Polish Cipher Bureau 432:Dwight D. Eisenhower 307:signals intelligence 80:Polish Cipher Bureau 5278:Force Research Unit 5089:Ministry of Defence 4961:Joint Support Group 4877:Metropolitan Police 4775:Winterbotham, F. W. 4530:Kozaczuk, Władysław 4384:Kozaczuk, Władysław 3980:Calvocoressi, Peter 3957:Brzezinski, Matthew 3794:, pp. 173–175. 3238:, pp. 227–230. 3174:, pp. 187–188. 3113:, pp. 315–316. 2918:, pp. 146–153. 2760:, pp. 307–309. 1924:In 1953, the CIA's 1686:Postwar disclosures 1626:Postwar suppression 1360:Operation Bodyguard 1327:The success of the 1242:Double Cross System 1078:RAF Fighter Command 1063:Battle of the Beams 968:Use of intelligence 940:, headquartered in 832:RAF Fighter Command 662:Geheimfernschreiber 545:. These produced a 296:was the designation 257:with covers removed 255:Lorenz SZ42 machine 4956:Intelligence Corps 4688:. London: Cassel. 4470:on 26 January 2001 4361:Knightley, Phillip 4001:Churchill, Winston 3933:Budiansky, Stephen 3692:on 3 February 2016 3458:on 17 January 2009 3085:. pp. 74–77. 2486:, pp. 242–43. 2379:on 2 February 2017 1968:The Imitation Game 1854:F. W. Winterbotham 1835:Arthur Schlesinger 1692:Władysław Kozaczuk 1493: 1415:RAF Bomber Command 1387:Operation Overlord 1364:Operation Overlord 1266:from 1942 onwards. 1102:Operation Sea Lion 1082:RAF Bentley Priory 817:F. W. Winterbotham 800:Army and Air Force 768: 679:W. T. "Bill" Tutte 524: 516: 463:Bernard Montgomery 428:F. W. Winterbotham 372:human intelligence 5296: 5295: 5099:Strategic Command 4767:978-0-19-280132-6 4745:978-0-297-78717-4 4686:The Red Orchestra 4634:978-0-330-41929-1 4589:978-0-911333-91-6 4567:978-0-14-193886-8 4547:978-0-89093-547-7 4426:978-0-14-139042-0 4417:Ultra goes to War 4404:978-0-89093-547-7 4337:978-0-684-83130-5 4295:978-0-241-89746-1 4236:978-0-521-44304-3 4206:978-0-19-280132-6 4171:978-1-84354-331-2 4153:978-0-415-36194-1 4114:978-0-330-23446-7 4084:Deutsch, Harold C 4040:Copeland, B. Jack 4014:978-0-14-144173-3 3993:978-0-947712-41-9 3948:978-0-684-85932-3 3900:Bertrand, Gustave 3777:Winterbotham 1974 3728:www.jewishgen.org 3600:Winterbotham 1974 3524:Winterbotham 1974 3322:, pp. 86–91. 3320:Winterbotham 1974 3296:Winterbotham 1974 3210:978-0-316-35253-6 3172:Winterbotham 1974 3062:Winterbotham 1974 3002:Winterbotham 1974 2952:Calvocoressi 2001 2906:, pp. 60–61. 2904:Winterbotham 1974 2894:, pp. 56–58. 2892:Winterbotham 1974 2856:Calvocoressi 2001 2834:, pp. 27–31. 2832:Winterbotham 1974 2737:Los Angeles Times 2656:Calvocoressi 2001 2595:, pp. 61–67. 2474:, pp. 81–92. 2336:Winterbotham 1974 2252:, pp. 11–13. 2233:Winterbotham 1974 2070:The Polish Review 1926:Project ARTICHOKE 1904:off the coast of 1778:National Archives 1696:Bitwa o tajemnice 1607:Manhattan Project 1578:centimetric radar 1508:Effect on the war 1368:Normandy landings 1133:Operation Compass 1126:10 Downing Street 1070:Battle of Britain 856:P H Lyon Playfair 844:General Lord Gort 727:stepping switches 627:, chief engineer 484:direction finding 436:Sir Harry Hinsley 412:Winston Churchill 271:Part of Japanese 224: 223: 16:(Redirected from 5346: 4973:RAF Intelligence 4847:Security Service 4822: 4815: 4808: 4799: 4798: 4791: 4779:The Ultra Secret 4770: 4748: 4722: 4704:Welchman, Gordon 4699: 4680: 4656: 4637: 4615: 4592: 4571: 4550: 4526:Rejewski, Marian 4508:Rejewski, Marian 4504: 4478: 4477: 4475: 4456: 4429: 4407: 4379: 4356: 4349:The Ultra Secret 4340: 4319: 4298: 4275: 4262: 4261: 4259: 4254: 4239: 4218: 4209: 4188: 4186: 4174: 4156: 4138: 4137: 4135: 4130: 4117: 4101:Farago, Ladislas 4096: 4094: 4079: 4060: 4031: 4017: 3996: 3984:Top Secret Ultra 3975: 3973: 3971: 3959:(24 July 2005). 3951: 3928: 3907: 3895: 3877: 3845: 3844: 3826: 3820: 3819: 3801: 3795: 3789: 3780: 3774: 3768: 3767:, pp. 66–67 3765:Schlesinger 1992 3762: 3756: 3750: 3744: 3742:Riegner Telegram 3738: 3732: 3731: 3720: 3714: 3708: 3702: 3701: 3699: 3697: 3688:. Archived from 3682: 3676: 3669: 3663: 3657: 3651: 3645: 3639: 3633: 3627: 3621: 3615: 3609: 3603: 3597: 3591: 3585: 3579: 3578: 3567: 3561: 3556: 3548: 3542: 3541: 3533: 3527: 3521: 3515: 3514: 3512: 3510: 3495: 3489: 3488: 3482: 3477: 3475: 3467: 3465: 3463: 3457: 3450: 3441: 3435: 3429: 3423: 3422: 3420: 3418: 3404: 3398: 3392: 3386: 3380: 3374: 3368: 3362: 3356: 3350: 3349: 3348: 3346: 3337:, archived from 3329: 3323: 3317: 3311: 3305: 3299: 3293: 3287: 3281: 3275: 3269: 3263: 3257: 3251: 3245: 3239: 3233: 3227: 3221: 3215: 3214: 3196: 3187: 3181: 3175: 3169: 3163: 3162: 3144: 3138: 3132: 3126: 3120: 3114: 3108: 3102: 3096: 3090: 3089: 3074: 3065: 3059: 3053: 3047: 3041: 3035: 3029: 3023: 3017: 3011: 3005: 2999: 2993: 2987: 2981: 2980: 2978: 2976: 2971:on 29 April 2011 2961: 2955: 2949: 2943: 2937: 2931: 2925: 2919: 2913: 2907: 2901: 2895: 2889: 2883: 2877: 2871: 2865: 2859: 2853: 2847: 2841: 2835: 2829: 2823: 2817: 2811: 2805: 2799: 2798: 2796: 2794: 2789:on 29 April 2011 2785:. Archived from 2779: 2773: 2767: 2761: 2755: 2749: 2748: 2746: 2744: 2728: 2722: 2716: 2710: 2704: 2695: 2689: 2683: 2677: 2671: 2665: 2659: 2653: 2647: 2641: 2635: 2629: 2623: 2617: 2608: 2602: 2596: 2590: 2584: 2578: 2563: 2556: 2550: 2544: 2538: 2532: 2526: 2520: 2514: 2508: 2499: 2493: 2487: 2481: 2475: 2469: 2463: 2457: 2451: 2445: 2439: 2438: 2404: 2389: 2388: 2386: 2384: 2369: 2363: 2357: 2351: 2345: 2339: 2333: 2327: 2326: 2303: 2294: 2293: 2287: 2279: 2271: 2265: 2259: 2253: 2247: 2236: 2230: 2224: 2223: 2214: 2208: 2207: 2187: 2181: 2180: 2160: 2154: 2153: 2141: 2135: 2129: 2123: 2117: 2098: 2053: 2047: 2044: 2038: 2027: 2021: 2002: 1996: 1985: 1892:wartime partners 1827:Einsatz Reinhard 1746:The Ultra Secret 1739:Gustave Bertrand 1704:The Codebreakers 1644:The Ultra Secret 1527: 1419:Frederick Taylor 1380: 1345: 1253:Battle of Midway 1235: 1225: 1216: 1180: 1099: 1089: 1074:Sir Hugh Dowding 1055: 1046: 1033:Battle of France 1001:Battle of France 868:Security Service 842:(BEF) headed by 611: 480:traffic analysis 349:. Several other 297: 268: 251: 234: 216: 209: 202: 44: 32: 31: 21: 5354: 5353: 5349: 5348: 5347: 5345: 5344: 5343: 5299: 5298: 5297: 5292: 5255:No. 30 Commando 5154: 5148: 5121: 5115: 5043: 5037: 5017: 5010: 4989: 4982: 4929: 4922: 4908: 4901: 4838: 4831: 4826: 4796: 4789: 4768: 4746: 4720: 4696: 4678: 4653: 4635: 4613: 4590: 4568: 4548: 4516:Henryk Zygalski 4494: 4473: 4471: 4446: 4427: 4405: 4377: 4338: 4317: 4296: 4285:Most Secret War 4257: 4255: 4252: 4237: 4207: 4184: 4172: 4154: 4133: 4131: 4128: 4115: 4092: 4076: 4058: 4015: 3994: 3969: 3967: 3965:Washington Post 3949: 3926: 3912:Beesly, Patrick 3893: 3875: 3864:Body of Secrets 3853: 3848: 3841: 3827: 3823: 3816: 3802: 3798: 3790: 3783: 3775: 3771: 3763: 3759: 3751: 3747: 3739: 3735: 3722: 3721: 3717: 3709: 3705: 3695: 3693: 3684: 3683: 3679: 3670: 3666: 3658: 3654: 3646: 3642: 3634: 3630: 3622: 3618: 3610: 3606: 3598: 3594: 3586: 3582: 3568: 3564: 3549: 3545: 3534: 3530: 3522: 3518: 3508: 3506: 3496: 3492: 3480: 3478: 3469: 3468: 3461: 3459: 3455: 3448: 3442: 3438: 3430: 3426: 3416: 3414: 3406: 3405: 3401: 3393: 3389: 3381: 3377: 3369: 3365: 3357: 3353: 3344: 3342: 3341:on 2 April 2013 3331: 3330: 3326: 3318: 3314: 3306: 3302: 3294: 3290: 3282: 3278: 3270: 3266: 3258: 3254: 3246: 3242: 3234: 3230: 3222: 3218: 3211: 3197: 3190: 3182: 3178: 3170: 3166: 3159: 3145: 3141: 3133: 3129: 3121: 3117: 3109: 3105: 3097: 3093: 3083:Military Review 3075: 3068: 3060: 3056: 3048: 3044: 3036: 3032: 3024: 3020: 3012: 3008: 3000: 2996: 2988: 2984: 2974: 2972: 2963: 2962: 2958: 2950: 2946: 2938: 2934: 2926: 2922: 2914: 2910: 2902: 2898: 2890: 2886: 2878: 2874: 2866: 2862: 2854: 2850: 2842: 2838: 2830: 2826: 2818: 2814: 2806: 2802: 2792: 2790: 2781: 2780: 2776: 2768: 2764: 2756: 2752: 2742: 2740: 2729: 2725: 2717: 2713: 2705: 2698: 2690: 2686: 2678: 2674: 2668:Stephenson 2004 2666: 2662: 2654: 2650: 2642: 2638: 2630: 2626: 2618: 2611: 2603: 2599: 2591: 2587: 2579: 2566: 2560:Brzezinski 2005 2557: 2553: 2545: 2541: 2533: 2529: 2521: 2517: 2509: 2502: 2494: 2490: 2482: 2478: 2470: 2466: 2458: 2454: 2446: 2442: 2427:10.1145/3018994 2405: 2392: 2382: 2380: 2371: 2370: 2366: 2358: 2354: 2346: 2342: 2334: 2330: 2323: 2304: 2297: 2281: 2280: 2272: 2268: 2260: 2256: 2248: 2239: 2231: 2227: 2217: 2215: 2211: 2204: 2188: 2184: 2177: 2161: 2157: 2142: 2138: 2130: 2126: 2118: 2111: 2107: 2102: 2101: 2094:Daily Telegraph 2054: 2050: 2045: 2041: 2028: 2024: 2003: 1999: 1986: 1982: 1977: 1938: 1930:Project MKUltra 1914:John Chatterton 1884:John Cairncross 1847: 1788:Historians and 1786: 1723:Ladislas Farago 1688: 1628: 1528: 1525: 1510: 1482: 1429: 1394:Operation Cobra 1377:Panzergrenadier 1289:Operation Torch 1273:victory at the 1151:Battle of Crete 970: 954:John Cairncross 946:Rudolf Roessler 938:"Lucy" spy ring 934: 900:Buckinghamshire 888: 864: 802: 760: 715: 701:cipher machine 695: 658:Lorenz SZ 40/42 643: 637: 612: 610:Gordon Welchman 609: 598:Gordon Welchman 586:Marian Rejewski 535: 529: 508: 476: 453:. For example, 420:Stewart Menzies 405:Hagelin machine 397:Enigma decrypts 290: 288: 287: 286: 285: 283: 281: 277: 276: 275: 269: 260: 259: 258: 252: 243: 242: 241: 235: 220: 191: 173: 110:Zygalski sheets 70:Breaking Enigma 64: 28: 23: 22: 15: 12: 11: 5: 5352: 5342: 5341: 5336: 5334:Bletchley Park 5331: 5326: 5321: 5316: 5311: 5294: 5293: 5291: 5290: 5285: 5280: 5275: 5270: 5265: 5259: 5258: 5257: 5252: 5242: 5237: 5236: 5235: 5230: 5225: 5222: 5217: 5212: 5209: 5204: 5199: 5194: 5189: 5184: 5179: 5174: 5169: 5158: 5156: 5150: 5149: 5147: 5146: 5141: 5136: 5131: 5125: 5123: 5117: 5116: 5114: 5113: 5108: 5103: 5102: 5101: 5096: 5086: 5081: 5080: 5079: 5069: 5067:Cabinet Office 5064: 5059: 5054: 5047: 5045: 5039: 5038: 5036: 5035: 5029: 5022: 5020: 5012: 5011: 5009: 5008: 5007: 5006: 4994: 4992: 4984: 4983: 4981: 4980: 4975: 4970: 4965: 4964: 4963: 4953: 4952: 4951: 4946: 4934: 4932: 4924: 4923: 4921: 4920: 4913: 4911: 4903: 4902: 4900: 4899: 4898: 4897: 4892: 4887: 4874: 4869: 4863: 4857: 4856: 4855: 4843: 4841: 4833: 4832: 4825: 4824: 4817: 4810: 4802: 4795: 4794: 4787: 4771: 4766: 4749: 4744: 4728: 4719:0-14-00-5305-0 4718: 4700: 4694: 4681: 4676: 4657: 4651: 4638: 4633: 4621:Smith, Michael 4617: 4611: 4593: 4588: 4572: 4566: 4551: 4546: 4522: 4505: 4492: 4479: 4457: 4444: 4431: 4425: 4409: 4403: 4392:W kręgu enigmy 4380: 4375: 4357: 4341: 4336: 4320: 4315: 4299: 4294: 4276: 4264: 4244:Hinsley, F. H. 4240: 4235: 4223:Hinsley, F. H. 4219: 4210: 4205: 4193:Hinsley, F. H. 4189: 4175: 4170: 4157: 4152: 4139: 4119: 4113: 4097: 4080: 4074: 4061: 4056: 4036:Copeland, Jack 4032: 4018: 4013: 3997: 3992: 3976: 3953: 3947: 3941:, Free Press, 3929: 3924: 3908: 3896: 3891: 3878: 3873: 3859:Bamford, James 3854: 3852: 3849: 3847: 3846: 3839: 3821: 3814: 3796: 3792:Knightley 1986 3781: 3769: 3757: 3745: 3733: 3715: 3703: 3677: 3673:Science Museum 3664: 3652: 3650:, p. 359. 3640: 3638:, p. 674. 3628: 3626:, p. 664. 3616: 3614:, p. 506. 3604: 3592: 3580: 3562: 3543: 3528: 3516: 3498:Hinsley, F.H. 3490: 3481:|journal= 3436: 3424: 3399: 3387: 3385:, p. 165. 3375: 3363: 3351: 3324: 3312: 3310:, p. 202. 3300: 3298:, p. 180. 3288: 3276: 3274:, p. 315. 3272:Budiansky 2000 3264: 3262:, p. 292. 3252: 3240: 3228: 3226:, p. 278. 3216: 3209: 3188: 3186:, p. 319. 3184:Budiansky 2000 3176: 3164: 3157: 3139: 3137:, p. 336. 3127: 3125:, p. 237. 3115: 3111:Budiansky 2000 3103: 3101:, p. 129. 3091: 3066: 3064:, p. 187. 3054: 3052:, p. 210. 3042: 3040:, p. 341. 3038:Budiansky 2000 3030: 3028:, p. 529. 3026:Churchill 2005 3018: 3016:, p. 104. 3006: 2994: 2982: 2956: 2944: 2932: 2920: 2908: 2896: 2884: 2882:, p. 124. 2872: 2860: 2848: 2836: 2824: 2822:, p. 301. 2820:Budiansky 2000 2812: 2800: 2774: 2772:, p. 170. 2762: 2750: 2723: 2721:, p. 142. 2711: 2696: 2694:, p. 152. 2684: 2682:, p. 138. 2672: 2660: 2658:, pp. 78. 2648: 2646:, p. 162. 2636: 2624: 2622:, p. 136. 2609: 2607:, p. 302. 2597: 2593:Wilkinson 1993 2585: 2564: 2551: 2539: 2537:, p. 103. 2527: 2515: 2513:, p. 289. 2500: 2488: 2476: 2464: 2452: 2450:, p. 145. 2440: 2390: 2364: 2362:, p. 297. 2352: 2340: 2328: 2321: 2295: 2266: 2254: 2237: 2225: 2209: 2202: 2182: 2175: 2155: 2136: 2124: 2108: 2106: 2103: 2100: 2099: 2048: 2039: 2022: 1997: 1979: 1978: 1976: 1973: 1972: 1971: 1964: 1959: 1954: 1949: 1944: 1937: 1934: 1846: 1843: 1831:Höfle telegram 1785: 1782: 1769:Bletchley Park 1761:Science Museum 1759:A 2012 London 1687: 1684: 1640:New York Times 1627: 1624: 1609:to create the 1582:conning towers 1523: 1509: 1506: 1490:Arlington Hall 1481: 1478: 1428: 1425: 1424: 1423: 1408: 1404: 1397: 1390: 1371: 1356: 1347: 1325: 1318: 1311: 1304:Doolittle Raid 1300:Balalae Island 1292: 1285: 1278: 1267: 1256: 1245: 1218: 1209: 1190: 1165: 1154: 1147: 1146:in March 1941. 1140: 1129: 1114:Coventry Blitz 1109: 1105: 1092: 1066: 1058:Dr R. V. Jones 1036: 969: 966: 958:Alexander Radó 933: 930: 887: 884: 863: 860: 801: 798: 780:Bletchley Park 759: 756: 741:Heer/Luftwaffe 714: 711: 707:Bletchley Park 694: 691: 639:Main article: 636: 633: 621:Hugh Alexander 607: 531:Main article: 528: 525: 507: 504: 496:radio networks 475: 472: 455:Andrew Roberts 416:King George VI 393:Enigma machine 356:The code name 327:Bletchley Park 279: 278: 273:PURPLE machine 270: 263: 262: 261: 253: 246: 245: 244: 238:Enigma machine 236: 229: 228: 227: 226: 225: 222: 221: 219: 218: 211: 204: 196: 193: 192: 190: 189: 183: 180: 179: 175: 174: 172: 171: 166: 161: 160: 159: 154: 149: 144: 139: 134: 129: 124: 117:Bletchley Park 114: 113: 112: 107: 102: 97: 92: 87: 76: 73: 72: 66: 65: 63: 62: 56: 53: 52: 50:Enigma machine 46: 45: 37: 36: 26: 9: 6: 4: 3: 2: 5351: 5340: 5337: 5335: 5332: 5330: 5327: 5325: 5322: 5320: 5317: 5315: 5312: 5310: 5307: 5306: 5304: 5289: 5286: 5284: 5281: 5279: 5276: 5274: 5271: 5269: 5266: 5263: 5260: 5256: 5253: 5251: 5248: 5247: 5246: 5243: 5241: 5238: 5234: 5231: 5229: 5226: 5223: 5221: 5218: 5216: 5213: 5210: 5208: 5205: 5203: 5200: 5198: 5195: 5193: 5190: 5188: 5185: 5183: 5180: 5178: 5175: 5173: 5170: 5168: 5165: 5164: 5163: 5160: 5159: 5157: 5151: 5145: 5142: 5140: 5137: 5135: 5132: 5130: 5127: 5126: 5124: 5118: 5112: 5109: 5107: 5104: 5100: 5097: 5095: 5092: 5091: 5090: 5087: 5085: 5082: 5078: 5075: 5074: 5073: 5070: 5068: 5065: 5063: 5060: 5058: 5055: 5052: 5049: 5048: 5046: 5040: 5033: 5030: 5027: 5024: 5023: 5021: 5019: 5013: 5005: 5002: 5001: 4999: 4996: 4995: 4993: 4991: 4985: 4979: 4976: 4974: 4971: 4969: 4966: 4962: 4959: 4958: 4957: 4954: 4950: 4947: 4945: 4942: 4941: 4939: 4936: 4935: 4933: 4931: 4925: 4918: 4915: 4914: 4912: 4910: 4904: 4896: 4893: 4891: 4888: 4886: 4883: 4882: 4881: 4878: 4875: 4873: 4870: 4867: 4864: 4861: 4858: 4854: 4851: 4850: 4848: 4845: 4844: 4842: 4840: 4834: 4830: 4823: 4818: 4816: 4811: 4809: 4804: 4803: 4800: 4793:inaccuracies. 4790: 4788:0-06-014678-8 4784: 4780: 4776: 4772: 4769: 4763: 4759: 4755: 4754:Hinsley, F.H. 4750: 4747: 4741: 4737: 4733: 4729: 4726: 4721: 4715: 4711: 4710: 4705: 4701: 4697: 4691: 4687: 4682: 4679: 4677:0-7475-7084-1 4673: 4669: 4665: 4664: 4658: 4654: 4652:1-84176-693-3 4648: 4644: 4639: 4636: 4630: 4626: 4622: 4618: 4614: 4612:1-85702-879-1 4608: 4604: 4603: 4598: 4594: 4591: 4585: 4581: 4577: 4573: 4569: 4563: 4559: 4558: 4552: 4549: 4543: 4539: 4535: 4531: 4527: 4523: 4521: 4520:Kozaczuk 1984 4517: 4513: 4512:Jerzy Różycki 4509: 4506: 4503: 4499: 4495: 4493:1-84375-252-2 4489: 4485: 4480: 4469: 4465: 4464: 4458: 4455: 4451: 4447: 4445:0-7110-2888-5 4441: 4437: 4432: 4428: 4422: 4418: 4414: 4413:Lewin, Ronald 4410: 4406: 4400: 4396: 4393: 4389: 4385: 4381: 4378: 4376:0-393-02386-9 4372: 4368: 4367: 4362: 4358: 4354: 4350: 4346: 4342: 4339: 4333: 4329: 4325: 4321: 4318: 4316:0-02-560460-0 4312: 4308: 4304: 4300: 4297: 4291: 4287: 4286: 4281: 4277: 4273: 4269: 4265: 4251: 4250: 4245: 4241: 4238: 4232: 4228: 4224: 4220: 4216: 4211: 4208: 4202: 4198: 4194: 4190: 4183: 4182: 4176: 4173: 4167: 4163: 4158: 4155: 4149: 4145: 4140: 4127: 4126: 4120: 4116: 4110: 4107:, Pan Books, 4106: 4102: 4098: 4091: 4090: 4085: 4081: 4077: 4075:9781780962436 4071: 4067: 4062: 4059: 4057:0-19-825080-0 4053: 4049: 4045: 4041: 4037: 4033: 4030: 4026: 4025: 4019: 4016: 4010: 4006: 4002: 3998: 3995: 3989: 3985: 3981: 3977: 3966: 3962: 3958: 3954: 3950: 3944: 3940: 3939: 3934: 3930: 3927: 3925:0-7221-1539-3 3921: 3917: 3913: 3909: 3905: 3901: 3897: 3894: 3892:0-7126-6521-8 3888: 3884: 3879: 3876: 3874:0-385-49907-8 3870: 3867:, Doubleday, 3866: 3865: 3860: 3856: 3855: 3842: 3840:9781538728031 3836: 3832: 3825: 3817: 3815:9781440858116 3811: 3807: 3800: 3793: 3788: 3786: 3779:, p. 25. 3778: 3773: 3766: 3761: 3755:, p. 124 3754: 3749: 3743: 3737: 3729: 3725: 3719: 3713:, p. 126 3712: 3707: 3691: 3687: 3681: 3674: 3668: 3661: 3660:Bertrand 1973 3656: 3649: 3644: 3637: 3632: 3625: 3620: 3613: 3608: 3601: 3596: 3589: 3584: 3576: 3572: 3566: 3559: 3554: 3547: 3539: 3532: 3525: 3520: 3505: 3501: 3494: 3486: 3473: 3454: 3447: 3440: 3433: 3428: 3413: 3409: 3403: 3396: 3391: 3384: 3379: 3372: 3367: 3360: 3355: 3340: 3336: 3335: 3328: 3321: 3316: 3309: 3304: 3297: 3292: 3286:, p. 40. 3285: 3280: 3273: 3268: 3261: 3256: 3250:, p. 39. 3249: 3244: 3237: 3232: 3225: 3220: 3212: 3206: 3202: 3195: 3193: 3185: 3180: 3173: 3168: 3160: 3158:9780253031433 3154: 3150: 3143: 3136: 3131: 3124: 3119: 3112: 3107: 3100: 3095: 3088: 3084: 3080: 3073: 3071: 3063: 3058: 3051: 3046: 3039: 3034: 3027: 3022: 3015: 3010: 3003: 2998: 2991: 2986: 2970: 2966: 2960: 2954:, p. 94. 2953: 2948: 2942:, p. 64. 2941: 2936: 2929: 2924: 2917: 2912: 2905: 2900: 2893: 2888: 2881: 2876: 2870:, p. 83. 2869: 2864: 2858:, p. 90. 2857: 2852: 2846:, p. 92. 2845: 2840: 2833: 2828: 2821: 2816: 2810:, p. 56. 2809: 2808:Welchman 1984 2804: 2788: 2784: 2778: 2771: 2766: 2759: 2754: 2739:(book review) 2738: 2734: 2727: 2720: 2715: 2708: 2703: 2701: 2693: 2688: 2681: 2676: 2670:, p. 56. 2669: 2664: 2657: 2652: 2645: 2640: 2634:, p. 36. 2633: 2628: 2621: 2616: 2614: 2606: 2601: 2594: 2589: 2582: 2581:Hinsley 1993a 2577: 2575: 2573: 2571: 2569: 2562:, p. 18) 2561: 2555: 2548: 2547:Hinsley 1993a 2543: 2536: 2531: 2525:, p. 17. 2524: 2519: 2512: 2511:Welchman 1984 2507: 2505: 2497: 2496:Copeland 2004 2492: 2485: 2484:Rejewski 1984 2480: 2473: 2472:Kozaczuk 1984 2468: 2461: 2460:Copeland 2004 2456: 2449: 2444: 2436: 2432: 2428: 2424: 2420: 2416: 2415: 2410: 2403: 2401: 2399: 2397: 2395: 2378: 2374: 2368: 2361: 2356: 2349: 2344: 2337: 2332: 2324: 2322:9780195113907 2318: 2314: 2313: 2308: 2302: 2300: 2291: 2285: 2277: 2270: 2263: 2258: 2251: 2246: 2244: 2242: 2234: 2229: 2222: 2221: 2213: 2205: 2203:9780684859323 2199: 2195: 2194: 2186: 2178: 2176:9781849542623 2172: 2168: 2167: 2159: 2151: 2147: 2140: 2134:, p. 64. 2133: 2128: 2122:, p. xx. 2121: 2116: 2114: 2109: 2096: 2095: 2090: 2086: 2082: 2081: 2076: 2072: 2071: 2066: 2062: 2057: 2052: 2043: 2036: 2032: 2026: 2019: 2015: 2011: 2007: 2001: 1994: 1990: 1984: 1980: 1970: 1969: 1965: 1963: 1960: 1958: 1955: 1953: 1950: 1948: 1945: 1943: 1940: 1939: 1933: 1931: 1927: 1922: 1919: 1915: 1911: 1910:Richie Kohler 1907: 1903: 1902: 1895: 1893: 1889: 1888:Anthony Blunt 1885: 1881: 1877: 1873: 1869: 1865: 1863: 1859: 1855: 1851: 1842: 1840: 1836: 1832: 1828: 1824: 1820: 1816: 1812: 1808: 1803: 1801: 1796: 1791: 1781: 1779: 1775: 1770: 1766: 1762: 1757: 1755: 1749: 1747: 1742: 1740: 1736: 1731: 1728: 1724: 1719: 1714: 1712: 1711: 1706: 1705: 1699: 1697: 1693: 1683: 1679: 1677: 1672: 1668: 1666: 1662: 1658: 1652: 1649: 1645: 1641: 1637: 1632: 1623: 1621: 1616: 1612: 1608: 1604: 1600: 1599:Western Front 1595: 1592: 1588: 1583: 1579: 1575: 1570: 1568: 1562: 1559: 1556: 1552: 1548: 1544: 1540: 1537: 1533: 1522: 1517: 1515: 1505: 1503: 1499: 1491: 1486: 1477: 1474: 1472: 1471: 1466: 1465:Caribbean Sea 1462: 1457: 1453: 1450: 1445: 1441: 1439: 1433: 1420: 1416: 1412: 1409: 1405: 1402: 1398: 1395: 1391: 1388: 1384: 1379: 1378: 1372: 1369: 1365: 1361: 1357: 1354: 1348: 1344: 1343: 1337: 1336: 1330: 1326: 1323: 1319: 1316: 1312: 1309: 1305: 1301: 1297: 1293: 1290: 1286: 1283: 1279: 1276: 1272: 1268: 1265: 1261: 1257: 1255:in June 1942. 1254: 1250: 1246: 1243: 1239: 1238:double agents 1234: 1229: 1224: 1219: 1215: 1210: 1207: 1203: 1199: 1195: 1191: 1188: 1184: 1179: 1174: 1170: 1166: 1163: 1159: 1155: 1152: 1148: 1145: 1141: 1138: 1134: 1130: 1127: 1123: 1122:Ditchley Park 1119: 1115: 1110: 1106: 1103: 1098: 1093: 1088: 1083: 1079: 1075: 1071: 1067: 1064: 1059: 1054: 1050: 1045: 1043: 1037: 1034: 1031:prior to the 1030: 1029:Low Countries 1026: 1025: 1024: 1021: 1018: 1014: 1010: 1005: 1002: 998: 994: 989: 987: 986: 980: 974: 965: 963: 962:Harry Hinsley 959: 955: 951: 950:cryptanalysis 947: 943: 939: 929: 926: 924: 920: 915: 912: 908: 903: 901: 897: 893: 883: 881: 877: 873: 869: 859: 857: 853: 849: 845: 841: 835: 833: 829: 825: 820: 818: 815: 814:Group Captain 811: 806: 797: 794: 792: 788: 783: 781: 777: 773: 764: 755: 753: 749: 744: 742: 738: 737: 732: 728: 724: 720: 710: 708: 704: 700: 690: 688: 687:Tommy Flowers 684: 680: 674: 671: 667: 663: 659: 655: 651: 648: 647:stream cipher 642: 635:Lorenz cipher 632: 630: 626: 622: 618: 606: 601: 599: 595: 591: 587: 582: 580: 576: 572: 568: 564: 560: 556: 552: 548: 544: 540: 534: 520: 512: 503: 501: 497: 493: 489: 485: 481: 471: 469: 464: 460: 456: 452: 447: 445: 441: 437: 433: 429: 425: 422:(head of the 421: 417: 413: 408: 406: 402: 398: 394: 390: 385: 383: 379: 378: 373: 369: 365: 361: 360: 354: 352: 348: 344: 340: 336: 332: 328: 324: 320: 316: 312: 308: 304: 301: 295: 294: 274: 267: 256: 250: 239: 233: 217: 212: 210: 205: 203: 198: 197: 195: 194: 188: 185: 184: 182: 181: 177: 176: 170: 167: 165: 162: 158: 155: 153: 150: 148: 145: 143: 140: 138: 135: 133: 130: 128: 125: 123: 120: 119: 118: 115: 111: 108: 106: 103: 101: 98: 96: 93: 91: 88: 86: 83: 82: 81: 78: 77: 75: 74: 71: 68: 67: 61: 60:Enigma rotors 58: 57: 55: 54: 51: 48: 47: 43: 39: 38: 34: 33: 30: 19: 5339:Cryptography 5044:Coordination 5016:Intelligence 4990:intelligence 4930:intelligence 4909:intelligence 4839:intelligence 4778: 4757: 4735: 4724: 4708: 4685: 4662: 4642: 4624: 4600: 4597:Singh, Simon 4579: 4556: 4537: 4483: 4472:, retrieved 4468:the original 4462: 4435: 4416: 4395: 4391: 4387: 4365: 4352: 4348: 4327: 4306: 4284: 4280:Jones, R. V. 4274:, p. 11 4271: 4256:, retrieved 4248: 4226: 4196: 4180: 4161: 4143: 4134:24 September 4132:, retrieved 4124: 4104: 4088: 4065: 4047: 4043: 4023: 4004: 3983: 3968:. Retrieved 3964: 3937: 3915: 3903: 3882: 3862: 3851:Bibliography 3830: 3824: 3805: 3799: 3772: 3760: 3748: 3736: 3727: 3718: 3706: 3694:. Retrieved 3690:the original 3680: 3667: 3655: 3643: 3631: 3619: 3607: 3602:, p. 1. 3595: 3590:, p. 5. 3583: 3574: 3571:Hartcup, Guy 3565: 3557: 3552: 3546: 3537: 3531: 3526:, p. 2. 3519: 3507:. Retrieved 3503: 3493: 3472:cite journal 3460:. Retrieved 3453:the original 3439: 3427: 3415:. Retrieved 3411: 3402: 3390: 3378: 3366: 3354: 3343:, retrieved 3339:the original 3333: 3327: 3315: 3303: 3291: 3279: 3267: 3255: 3243: 3231: 3219: 3200: 3179: 3167: 3148: 3142: 3130: 3118: 3106: 3094: 3086: 3057: 3045: 3033: 3021: 3009: 2997: 2992:, p. 3. 2990:Hinsley 1993 2985: 2973:. Retrieved 2969:the original 2959: 2947: 2940:Bennett 1999 2935: 2923: 2911: 2899: 2887: 2875: 2863: 2851: 2839: 2827: 2815: 2803: 2791:. Retrieved 2787:the original 2777: 2770:Tarrant 1995 2765: 2753: 2741:. Retrieved 2736: 2726: 2714: 2707:Pidgeon 2003 2687: 2675: 2663: 2651: 2639: 2627: 2605:Bennett 1999 2600: 2588: 2554: 2542: 2530: 2523:Bamford 2001 2518: 2491: 2479: 2467: 2455: 2443: 2421:(1): 29–35. 2418: 2412: 2381:. Retrieved 2377:the original 2367: 2360:Roberts 2009 2355: 2350:, p. 1. 2348:Deutsch 1977 2343: 2331: 2311: 2275: 2269: 2262:Hinsley 1996 2257: 2250:Hinsley 1993 2228: 2219: 2212: 2192: 2185: 2165: 2158: 2150:The Guardian 2149: 2139: 2127: 2092: 2089:Toby Harnden 2078: 2077:, author of 2075:Max Hastings 2068: 2064: 2051: 2042: 2030: 2025: 2017: 2013: 2009: 2005: 2000: 1983: 1966: 1923: 1917: 1900: 1896: 1870: 1866: 1857: 1852: 1848: 1811:Soviet Union 1804: 1787: 1758: 1754:Codebreakers 1753: 1750: 1745: 1743: 1734: 1732: 1726: 1721: 1716: 1709: 1702: 1700: 1695: 1694:in his book 1689: 1680: 1673: 1669: 1653: 1643: 1639: 1633: 1629: 1596: 1571: 1564: 1560: 1557: 1553: 1549: 1545: 1541: 1538: 1535: 1530: 1519: 1511: 1494: 1475: 1468: 1458: 1454: 1446: 1442: 1434: 1430: 1351: 1335:Duke of York 1334: 1271:Montgomery's 1117: 1022: 1012: 1006: 990: 983: 975: 971: 935: 927: 923:one-time pad 916: 907:National HRO 904: 896:Whaddon Hall 889: 872:Herbert Hart 865: 836: 828:Air Ministry 821: 807: 803: 795: 784: 769: 758:Distribution 745: 740: 734: 716: 696: 675: 660:(Tunny) and 644: 623:and, at the 614: 603: 583: 536: 477: 468:Thomas Haigh 459:Erwin Rommel 448: 409: 387:Much of the 386: 375: 363: 358: 357: 355: 347:Ultra Secret 346: 342: 330: 292: 291: 289: 186: 29: 5072:Home Office 4732:West, Nigel 4474:18 February 4355:, p. 5 4345:Kahn, David 4324:Kahn, David 4303:Kahn, David 4268:Hunt, David 3753:Hanyok 2004 3711:Hanyok 2004 3696:8 September 3648:Farago 1974 3636:Farago 1974 3624:Farago 1974 3383:Ferris 2005 3359:Momsen 2007 3308:Taylor 2005 3284:Farley 1980 3248:Farley 1980 2975:16 December 2758:Crowdy 2011 2719:Beesly 1977 2632:Beesly 1977 2549:, p. 8 2535:Gannon 2006 2067:, 2005, in 1648:Third World 1620:Guy Hartcup 1611:atomic bomb 1574:Karl Dönitz 1558:Sincerely, 1461:Karl Dönitz 1342:Scharnhorst 1331:, in which 1204:to prevent 1183:"wolfpacks" 1068:During the 942:Switzerland 699:rotor-based 650:teleprinter 629:Harold Keen 617:Alan Turing 555:German Army 444:atomic bomb 343:Most Secret 341:then used ( 319:teleprinter 298:adopted by 127:Herivel tip 122:Banburismus 5303:Categories 5153:Historical 5120:Review and 5042:Policy and 5018:assessment 4695:0471134392 3462:14 January 3417:3 November 3345:9 February 3260:Lewin 2001 3236:Lewin 2001 3224:Lewin 2001 3135:Jones 1978 3123:Lewin 2001 3099:Smith 2007 3050:Lewin 2001 3014:Lewin 2001 2916:Jones 1978 2880:Jones 1978 2868:Lewin 2001 2844:Jones 1978 2448:Singh 1999 2383:25 January 2132:Lewin 2001 2105:References 1908:by divers 1906:New Jersey 1880:Kim Philby 1819:Jan Karski 1805:Following 1636:David Kahn 1613:. Author 1587:periscopes 1536:July 1945 1296:Yamamoto's 1260:Peenemünde 1202:Auchinleck 1108:cancelled. 1053:Knickebein 1042:KNICKEBEIN 824:War Office 683:Max Newman 579:Dilly Knox 567:Nazi party 551:Reichswehr 492:land lines 488:Phoney War 384:" cipher. 351:cryptonyms 100:Cyclometer 5122:Oversight 4706:(1984) , 4623:(2007) , 4454:181448256 4415:(2001) , 4326:(1997) , 4272:The Times 4246:(1996) , 4225:(1993a), 4103:(1974) , 4003:(2005) , 3982:(2001) , 3612:Kahn 1967 3588:Kahn 1974 3432:Kahn 1997 2928:Hunt 1976 2692:West 1986 2680:West 1986 2644:West 1986 2620:West 1986 2284:cite book 2031:Y Service 1872:Knightley 1765:centenary 1333:HMS 1214:Luftwaffe 1178:Luftwaffe 1097:Luftwaffe 1087:Luftwaffe 1013:Luftwaffe 979:indicator 925:systems. 880:St Albans 874:. In the 791:Admiralty 563:Air Force 500:Luftwaffe 311:encrypted 5155:agencies 4928:Military 4837:Domestic 4777:(1974), 4734:(1986), 4725:addendum 4599:(1999), 4502:56715513 4386:(1984), 4363:(1986), 4305:(1967), 4282:(1978), 4086:(1977), 3970:16 March 3935:(2000), 3914:(1977), 3902:(1973), 3861:(2001), 3573:(2000). 3560:, p. 26. 2435:41650745 2309:(1997). 1936:See also 1876:Cold War 1821:and the 1524:— 1470:B-Dienst 1206:Rommel's 1118:en route 993:PC Bruno 713:Japanese 670:Colossus 666:Sturgeon 608:— 588:and the 359:Boniface 164:PC Bruno 5250:Room 40 5000:(GCHQ) 4988:Signals 4907:Foreign 4258:23 July 4042:(ed.), 2085:C-SPAN2 2083:, in a 1858:postwar 1829:" (the 1676:V-E Day 1526:Hinsley 1401:Falaise 1192:In the 1173:U-boats 1091:source. 1035:in May. 914:SCU14. 911:Packard 719:Pacific 717:In the 693:Italian 600:wrote, 571:Gestapo 300:British 178:Related 85:Doubles 5034:(JTAC) 4868:(NBIS) 4849:(MI5) 4785: 4764: 4742: 4716: 4692: 4674: 4649: 4631: 4609: 4586: 4564: 4544: 4500: 4490: 4452: 4442: 4423: 4401: 4373: 4334: 4313: 4292: 4233: 4203: 4168: 4150: 4111: 4072: 4054: 4011: 3990: 3945: 3922: 3889: 3871: 3837: 3812: 3509:13 May 3207: 3155: 2793:8 July 2743:8 June 2433: 2319: 2200: 2173: 1989:PURPLE 1735:Enigma 1591:graphs 1547:them. 1449:Naples 1233:Abwehr 1223:Abwehr 1198:Wavell 1162:Stalin 1049:Cleves 1047:("The 1009:bombes 826:, the 723:Purple 575:Abwehr 553:. The 539:Enigma 527:Enigma 506:German 389:German 382:Purple 335:Allies 313:enemy 5264:(SOE) 5053:(JIC) 5028:(JIO) 4940:(DI) 4919:(MI6) 4862:(NCA) 4253:(PDF) 4185:(PDF) 4129:(PDF) 4093:(PDF) 3740:See: 3456:(PDF) 3449:(PDF) 2431:S2CID 2216:see: 1993:JN-25 1975:Notes 1947:Hut 8 1942:Hut 6 1918:U-869 1901:U-869 1837:, an 1710:U-505 1438:Malta 1407:man". 1137:Libya 985:cribs 919:TYPEX 852:Meaux 787:Hut 8 776:Hut 6 748:JN-25 736:Magic 377:Magic 364:Ultra 331:Ultra 315:radio 293:Ultra 187:Ultra 169:Cadix 157:Hut 8 152:Hut 6 147:Hut 4 142:Hut 3 137:Bombe 105:Bomba 95:Clock 90:Grill 5233:MI19 5228:MI17 5224:MI16 5220:MI15 5215:MI14 5211:MI12 5207:MI11 5202:MI10 4783:ISBN 4762:ISBN 4740:ISBN 4714:ISBN 4690:ISBN 4672:ISBN 4647:ISBN 4629:ISBN 4607:ISBN 4584:ISBN 4562:ISBN 4542:ISBN 4514:and 4498:OCLC 4488:ISBN 4476:2008 4450:OCLC 4440:ISBN 4421:ISBN 4399:ISBN 4371:ISBN 4332:ISBN 4311:ISBN 4290:ISBN 4260:2012 4231:ISBN 4201:ISBN 4166:ISBN 4148:ISBN 4136:2016 4109:ISBN 4070:ISBN 4052:ISBN 4046:plus 4009:ISBN 3988:ISBN 3972:2016 3943:ISBN 3920:ISBN 3887:ISBN 3869:ISBN 3835:ISBN 3810:ISBN 3698:2015 3511:2020 3485:help 3464:2015 3419:2013 3347:2011 3205:ISBN 3153:ISBN 2977:2010 2795:2010 2745:2016 2385:2017 2317:ISBN 2290:link 2198:ISBN 2171:ISBN 1991:and 1912:and 1886:and 1862:GCHQ 1795:P.L. 1774:GCHQ 1665:KL-7 1657:NEMA 1200:and 932:Lucy 703:C-38 681:and 654:Fish 619:and 605:use. 559:Navy 482:and 317:and 132:Crib 5329:MI6 5197:MI9 5192:MI8 5187:MI7 5182:MI4 5177:MI3 5172:MI2 5167:MI1 4668:202 4351:", 2423:doi 1839:OSS 1823:WJC 1800:NSA 1748:. 1385:in 1228:MI5 1120:to 898:in 876:SIS 850:at 810:MI6 368:MI6 325:at 5305:: 4670:, 4532:; 4496:, 4448:, 4027:, 3963:. 3784:^ 3726:. 3502:. 3476:: 3474:}} 3470:{{ 3410:. 3191:^ 3081:. 3069:^ 2735:. 2699:^ 2612:^ 2567:^ 2503:^ 2429:. 2419:60 2417:. 2411:. 2393:^ 2298:^ 2286:}} 2282:{{ 2240:^ 2148:. 2112:^ 2063:, 1894:. 1882:, 1817:, 1306:, 988:. 882:. 830:, 709:. 689:. 569:, 565:, 561:, 557:, 446:. 407:. 329:. 4821:e 4814:t 4807:v 4698:. 4655:. 4570:. 4217:. 4078:. 3974:. 3843:. 3818:. 3730:. 3700:. 3675:. 3662:. 3558:2 3513:. 3487:) 3483:( 3466:. 3434:. 3421:. 3373:. 3361:. 3213:. 3161:. 2979:. 2930:. 2797:. 2747:. 2709:. 2583:. 2558:( 2437:. 2425:: 2387:. 2338:. 2325:. 2292:) 2264:. 2152:. 1995:. 1793:( 1403:. 1396:. 1065:. 664:( 537:" 215:e 208:t 201:v 20:)

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Ultra (cryptography)

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