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Code (cryptography)
In cryptology, a code is a method used to encrypt a message that operates at the level of meaning; that is, words or phrases are converted into something else. A code might transform "change" into "CVGDK" or "cocktail lounge". The U.S. National Security Agency defined a code as "A substitution cryptosystem in which the plaintext elements are primarily words, phrases, or sentences, and the code equivalents (called "code groups") typically consist of letters or digits (or both) in otherwise meaningless combinations of identical length."A History of U.S. Communications Security; the David G. Boak Lectures National Security Agency (NSA), Volumes I, 1973, Volumes II 1981, partially released 2008, additional portions declassified October 14, 2015 A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, massa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
One-time Pad
In cryptography, the one-time pad (OTP) is an encryption technique that cannot be cracked, but requires the use of a single-use pre-shared key that is not smaller than the message being sent. In this technique, a plaintext is paired with a random secret key (also referred to as ''a one-time pad''). Then, each bit or character of the plaintext is encrypted by combining it with the corresponding bit or character from the pad using modular addition. The resulting ciphertext will be impossible to decrypt or break if the following four conditions are met: #The key must be at least as long as the plaintext. #The key must be random ( uniformly distributed in the set of all possible keys and independent of the plaintext), entirely sampled from a non-algorithmic, chaotic source such as a hardware random number generator. It is not sufficient for OTP keys to pass statistical randomness tests as such tests cannot measure entropy, and the number of bits of entropy must be at least equa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leslie Groves
Lieutenant General Leslie Richard Groves Jr. (17 August 1896 – 13 July 1970) was a United States Army Corps of Engineers officer who oversaw the construction of the Pentagon and directed the Manhattan Project, a top secret research project that developed the atomic bomb during World War II. The son of a U.S. Army chaplain, Groves lived at various Army posts during his childhood. In 1918, he graduated fourth in his class at the U.S. Military Academy at West Point and was commissioned into the U.S. Army Corps of Engineers. In 1929, he went to Nicaragua as part of an expedition to conduct a survey for the Inter-Oceanic Nicaragua Canal. Following the 1931 earthquake, Groves took over Managua's water supply system, for which he was awarded the Nicaraguan Presidential Medal of Merit. He attended the Command and General Staff School at Fort Leavenworth, Kansas, in 1935 and 1936; and the Army War College in 1938 and 1939, after which he was posted to the War Department General S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Bomb
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter. The first test of a fission ("atomic") bomb released an amount of energy approximately equal to . The first thermonuclear ("hydrogen") bomb test released energy approximately equal to . Nuclear bombs have had yields between 10 tons TNT (the W54) and 50 megatons for the Tsar Bomba (see TNT equivalent). A thermonuclear weapon weighing as little as can release energy equal to more than . A nuclear device no larger than a conventional bomb can devastate an entire city by blast, fire, and radiation. Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trinity Test
Trinity was the code name of the first detonation of a nuclear weapon. It was conducted by the United States Army at 5:29 a.m. on July 16, 1945, as part of the Manhattan Project. The test was conducted in the Jornada del Muerto desert about southeast of Socorro, New Mexico, on what was then the USAAF Alamogordo Bombing and Gunnery Range, now part of White Sands Missile Range. The only structures originally in the vicinity were the McDonald Ranch House and its ancillary buildings, which scientists used as a laboratory for testing bomb components. A base camp was constructed, and there were 425 people present on the weekend of the test. The code name "Trinity" was assigned by J. Robert Oppenheimer, the director of the Los Alamos Laboratory, inspired by the poetry of John Donne. The test was of an implosion-design plutonium device, informally nicknamed "The Gadget", of the same design as the Fat Man bomb later detonated over Nagasaki, Japan, on August 9, 1945. The compl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Stalin
Joseph Vissarionovich Stalin (born Ioseb Besarionis dze Jughashvili; – 5 March 1953) was a Georgian revolutionary and Soviet political leader who led the Soviet Union from 1924 until his death in 1953. He held power as General Secretary of the Communist Party of the Soviet Union (1922–1952) and Chairman of the Council of Ministers of the Soviet Union (1941–1953). Initially governing the country as part of a collective leadership, he consolidated power to become a dictator by the 1930s. Ideologically adhering to the Leninist interpretation of Marxism, he formalised these ideas as Marxism–Leninism, while his own policies are called Stalinism. Born to a poor family in Gori in the Russian Empire (now Georgia), Stalin attended the Tbilisi Spiritual Seminary before joining the Marxist Russian Social Democratic Labour Party. He edited the party's newspaper, ''Pravda'', and raised funds for Vladimir Lenin's Bolshevik faction via robberies, kidnappings and protection r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potsdam Conference
The Potsdam Conference (german: Potsdamer Konferenz) was held at Potsdam in the Soviet occupation zone from July 17 to August 2, 1945, to allow the three leading Allies to plan the postwar peace, while avoiding the mistakes of the Paris Peace Conference of 1919. The participants were the Soviet Union, the United Kingdom, and the United States. They were represented respectively by General Secretary Joseph Stalin, Prime Ministers Winston Churchill and Clement Attlee, and President Harry S. Truman. They gathered to decide how to administer Germany, which had agreed to an unconditional surrender nine weeks earlier. The goals of the conference also included establishing the postwar order, solving issues on the peace treaty, and countering the effects of the war. The foreign ministers and aides played key roles: Vyacheslav Molotov, Anthony Eden and Ernest Bevin, and James F. Byrnes. From July 17 to July 25, nine meetings were held, when the Conference was interrupted for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harry Truman
Harry S. Truman (May 8, 1884December 26, 1972) was the 33rd president of the United States, serving from 1945 to 1953. A leader of the Democratic Party, he previously served as the 34th vice president from January to April 1945 under Franklin Roosevelt and as a United States senator from Missouri from 1935 to January 1945. Assuming the presidency after Roosevelt's death, Truman implemented the Marshall Plan to rebuild the economy of Western Europe and established both the Truman Doctrine and NATO to contain the expansion of Soviet communism. He proposed numerous liberal domestic reforms, but few were enacted by the conservative coalition that dominated the Congress. Truman grew up in Independence, Missouri, and during World War I fought in France as a captain in the Field Artillery. Returning home, he opened a haberdashery in Kansas City, Missouri, and was elected as a judge of Jackson County in 1922. Truman was elected to the United States Senate from Missouri in 1934. In 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spanish Civil War
The Spanish Civil War ( es, Guerra Civil Española)) or The Revolution ( es, La Revolución, link=no) among Nationalists, the Fourth Carlist War ( es, Cuarta Guerra Carlista, link=no) among Carlists, and The Rebellion ( es, La Rebelión, link=no) or The Uprising ( es, La Sublevación, link=no) among Republicans. was a civil war in Spain fought from 1936 to 1939 between the Republicans and the Nationalists. Republicans were loyal to the left-leaning Popular Front government of the Second Spanish Republic, and consisted of various socialist, communist, separatist, anarchist, and republican parties, some of which had opposed the government in the pre-war period. The opposing Nationalists were an alliance of Falangists, monarchists, conservatives, and traditionalists led by a military junta among whom General Francisco Franco quickly achieved a preponderant role. Due to the international political climate at the time, the war had many facets and was variously viewed as class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D-day
The Normandy landings were the landing operations and associated airborne operations on Tuesday, 6 June 1944 of the Allied invasion of Normandy in Operation Overlord during World War II. Codenamed Operation Neptune and often referred to as D-Day, it was the largest seaborne invasion in history. The operation began the liberation of France (and later western Europe) and laid the foundations of the Allied victory on the Western Front. Planning for the operation began in 1943. In the months leading up to the invasion, the Allies conducted a substantial military deception, codenamed Operation Bodyguard, to mislead the Germans as to the date and location of the main Allied landings. The weather on D-Day was far from ideal, and the operation had to be delayed 24 hours; a further postponement would have meant a delay of at least two weeks, as the invasion planners had requirements for the phase of the moon, the tides, and the time of day that meant only a few days each month wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Resistance
The French Resistance (french: La Résistance) was a collection of organisations that fought the German occupation of France during World War II, Nazi occupation of France and the Collaborationism, collaborationist Vichy France, Vichy régime during the World War II, Second World War. Resistance Clandestine cell system, cells were small groups of armed men and women (called the Maquis (World War II), Maquis in rural areas) who, in addition to their guerrilla warfare activities, were also publishers of underground newspapers, providers of first-hand intelligence information, and maintainers of escape networks that helped Allies of World War II, Allied soldiers and airmen trapped behind enemy lines. The Resistance's men and women came from all economic levels and political leanings of French society, including émigrés, academics, students, Aristocratic family, aristocrats, conservative Catholic Church, Roman Catholics (including priests and Yvonne Beauvais, nuns), Protestantis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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