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John R. F. Jeffreys
John Robert Fisher Jeffreys (25 January 1916 – 13 January 1944) was a British mathematician and World War II codebreaker. A research fellow at Downing College, Cambridge, Jeffreys joined the codebreaking efforts at Bletchley Park in September 1939 alongside fellow Cambridge mathematicians Gordon Welchman, with whom he had previously worked closely, and Alan Turing. These three, together with Peter Twinn and working under Dilly Knox, formed the research section working on the German Enigma machine, and were housed in "The Cottage" at Bletchley Park. Jeffreys was put in charge of a small section manufacturing perforated sheets for use in the cryptanalysis of the Enigma, a task which took over three months, completed on 7 January 1940.Ralph Erskine, "The Poles Reveal their Secrets: Alastair Denniston's Account of the July 1939 Meeting at Pyry", pp. 294-305, ''Cryptologia'' 30(4), December 2006 One type were the Zygalski sheets, known as ''Netz'' at Bletchley Park, a technique ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zygalski Sheets (perforated Sheets)
The method of Zygalski sheets was a cryptology, cryptologic technique used by the Poland, Polish Biuro Szyfrów, Cipher Bureau before and during World War II, and during the war also by British cryptologists at Bletchley Park, to decryption, decrypt messages cipher, enciphered on German Enigma machines. The Zygalski-sheet apparatus takes its name from Polish Cipher Bureau mathematician–cryptologist Henryk Zygalski, who invented it about October 1938. Method Zygalski's device comprised a set of 26 perforated sheets for each of the, initially, six possible sequences for inserting the three rotors into the Enigma machine's scrambler. Each sheet related to the starting position of the left (slowest-moving) rotor. The 26 × 26 matrix represented the 676 possible starting positions of the middle and right rotors and was duplicated horizontally and vertically: ''a–z, a–y''. The sheets were punched with holes in the positions that would allow a "Cryptanalysis of the Enigma#Perfora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptanalysis Of The Enigma
Cryptanalysis of the Enigma ciphering system enabled the western Allies in World War II to read substantial amounts of Morse-coded radio communications of the Axis powers that had been enciphered using Enigma machines. This yielded military intelligence which, along with that from other decrypted Axis radio and teleprinter transmissions, was given the codename '' Ultra''. The Enigma machines were a family of portable cipher machines with rotor scramblers. Good operating procedures, properly enforced, would have made the plugboard Enigma machine unbreakable. However, most of the German military forces, secret services, and civilian agencies that used Enigma employed poor operating procedures, and it was these poor procedures that allowed the Enigma machines to be reverse-engineered and the ciphers to be read. The German plugboard-equipped Enigma became Nazi Germany's principal crypto-system. In December 1932 it was "broken" by mathematician Marian Rejewski at the Polish G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1944 Deaths
Events Below, the events of World War II have the "WWII" prefix. January * January 2 – WWII: ** Free France, Free French General Jean de Lattre de Tassigny is appointed to command First Army (France), French Army B, part of the Sixth United States Army Group in North Africa. ** Landing at Saidor: 13,000 US and Australian troops land on Papua New Guinea, in an attempt to cut off a Japanese retreat. * January 8 – WWII: Philippine Commonwealth troops enter the province of Ilocos Sur in northern Luzon and attack Japanese forces. * January 11 ** President of the United States Franklin D. Roosevelt proposes a Second Bill of Rights for social and economic security, in his State of the Union address. ** The Nazi German administration expands Kraków-PÅ‚aszów concentration camp into the larger standalone ''Konzentrationslager Plaszow bei Krakau'' in occupied Poland. * January 12 – WWII: Winston Churchill and Charles de Gaulle begin a 2-day conference in Marrakech ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1916 Births
Events Below, the events of the First World War have the "WWI" prefix. January * January 1 – The British Empire, British Royal Army Medical Corps carries out the first successful blood transfusion, using blood that had been stored and cooled. * January 9 – WWI: Gallipoli Campaign: The last British troops are evacuated from Gallipoli, as the Ottoman Empire prevails over a joint British and French operation to capture Constantinople. * January 10 – WWI: Erzurum Offensive: Russia defeats the Ottoman Empire. * January 12 – The Gilbert and Ellice Islands Colony, part of the British Empire, is established in present-day Tuvalu and Kiribati. * January 13 – WWI: Battle of Wadi (1916), Battle of Wadi: Ottoman Empire forces defeat the British, during the Mesopotamian campaign in modern-day Iraq. * January 29 – WWI: Paris is bombed by German Empire, German zeppelins. * January 31 – WWI: An attack is planned on Verdun, France. February * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fellows Of Downing College, Cambridge
{{disambiguation ...
Fellows may refer to Fellow, in plural form. Fellows or Fellowes may also refer to: Places *Fellows, California, USA *Fellows, Wisconsin, ghost town, USA Other uses *Fellows Auctioneers, established in 1876. *Fellowes, Inc., manufacturer of workspace products *Fellows, a partner in the firm of English canal carriers, Fellows Morton & Clayton *Fellows (surname) See also *North Fellows Historic District, listed on the National Register of Historic Places in Wapello County, Iowa *Justice Fellows (other) Justice Fellows may refer to: * Grant Fellows (1865–1929), associate justice of the Michigan Supreme Court * Raymond Fellows (1885–1957), associate justice of the Maine Supreme Judicial Court {{disambiguation, tndis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bletchley Park People
Bletchley is a constituent town of Milton Keynes, Buckinghamshire, England. It is situated in the south-west of Milton Keynes, and is split between the civil parishes of Bletchley and Fenny Stratford and West Bletchley. Bletchley is best known for Bletchley Park, the headquarters of Britain's World War II codebreaking organisation, and now a major tourist attraction. The National Museum of Computing is also located on the Park. History Origins and early modern history The town name is Anglo-Saxon and means ''Blæcca's clearing''. It was first recorded in manorial rolls in the 12th century as ''Bicchelai'', then later as ''Blechelegh'' (13th century) and ''Blecheley'' (14th–16th centuries). Just to the south of Fenny Stratford, there was Romano-British town, '' M'' on either side of Watling Street, a Roman road. Bletchley was originally a minor village on the outskirts of Fenny Stratford, of lesser importance than Water Eaton. Fenny Stratford fell into decline from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diabetes
Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased appetite. If left untreated, diabetes can cause many health complications. Acute complications can include diabetic ketoacidosis, hyperosmolar hyperglycemic state, or death. Serious long-term complications include cardiovascular disease, stroke, chronic kidney disease, foot ulcers, damage to the nerves, damage to the eyes, and cognitive impairment. Diabetes is due to either the pancreas not producing enough insulin, or the cells of the body not responding properly to the insulin produced. Insulin is a hormone which is responsible for helping glucose from food get into cells to be used for energy. There are three main types of diabetes mellitus: * Type 1 diabetes results from failure of the pancreas to produce enough insulin due to lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in which case it is known as latent tuberculosis. Around 10% of latent infections progress to active disease which, if left untreated, kill about half of those affected. Typical symptoms of active TB are chronic cough with blood-containing mucus, fever, night sweats, and weight loss. It was historically referred to as consumption due to the weight loss associated with the disease. Infection of other organs can cause a wide range of symptoms. Tuberculosis is spread from one person to the next through the air when people who have active TB in their lungs cough, spit, speak, or sneeze. People with Latent TB do not spread the disease. Active infection occurs more often in people with HIV/AIDS and in those who smoke. Diagnosis of active TB is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mavis Batey
Mavis Lilian Batey, MBE (née Lever; 5 May 1921 – 12 November 2013), was a British code-breaker during World War II. She was one of the leading female codebreakers at Bletchley Park. She later became a historian of gardening who campaigned to save historic parks and gardens, and an author. Batey was awarded the Veitch Memorial Medal in 1985, and made a Member of the Order of the British Empire (MBE) in 1987, in both cases for her work on the conservation of gardens. Early life Mavis Lilian Lever was born on 5 May 1921 in Dulwich to her seamstress mother and postal worker father. She was brought up in Norbury and went to Coloma Convent Girls' School in Croydon. She was studying German at University College, London at the outbreak of World War II: I was concentrating on German romantics and then I realised the German romantics would soon be overhead and I thought well, I really ought to do something better for the war effort. She decided to interrupt her university stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hut 6
Hut 6 was a wartime section of the Government Code and Cypher School (GC&CS) at Bletchley Park, Buckinghamshire, Britain, tasked with the solution of German Army and Air Force Enigma machine cyphers. Hut 8, by contrast, attacked Naval Enigma. Hut 6 was established at the initiative of Gordon Welchman, and was run initially by Welchman and fellow Cambridge mathematician John Jeffreys. Welchman's deputy, Stuart Milner-Barry, succeeded Welchman as head of Hut 6 in September 1943, at which point over 450 people were working in the section.Ralph Erskine, ''Barry, Sir (Philip) Stuart Milner- (1906–1995)'', Oxford Dictionary of National Biography, 2004. Hut 6 was partnered with Hut 3, which handled the translation and intelligence analysis of the raw decrypts provided by Hut 6. Location Hut 6 was originally named after the building in which the section was located. Welchman says the hut was 20 yards (18m) long by 10 yards (9m) wide, with two large rooms at the far end â ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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