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Known Plaintext
The known-plaintext attack (KPA) is an attack model for cryptanalysis where the attacker has access to both the plaintext (called a crib) and its encrypted version (ciphertext). These can be used to reveal secret keys and code books. The term "crib" originated at Bletchley Park, the British World War II decryption operation, where it was defined as: History The usage "crib" was adapted from a slang term referring to cheating (e.g., "I cribbed my answer from your test paper"). A "crib" originally was a literal or interlinear translation of a foreign-language text—usually a Latin or Greek text—that students might be assigned to translate from the original language. The idea behind a crib is that cryptologists were looking at incomprehensible ciphertext, but if they had a clue about some word or phrase that might be expected to be in the ciphertext, they would have a "wedge," a test to break into it. If their otherwise random attacks on the cipher managed to sometimes produce th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Attack Model
In cryptanalysis, attack models or attack types are a classification of cryptographic attacks specifying the kind of access a Cryptanalysis, cryptanalyst has to a system under attack when attempting to "break" an Encryption, encrypted message (also known as ''ciphertext'') generated by the system. The greater the access the cryptanalyst has to the system, the more useful information they can get to utilize for breaking the cypher. In cryptography, a sending party uses a cipher to encryption, encrypt (transform) a secret ''plaintext'' into a ''ciphertext'', which is sent over an insecure communication channel to the receiving party. The receiving party uses an inverse cipher to decryption, decrypt the ciphertext to obtain the plaintext. A secret knowledge is required to apply the inverse cipher to the ciphertext. This secret knowledge is usually a short number or string called a ''cryptographic key, key''. In a cryptographic attack a third party cryptanalyst analyzes the ciphertex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Sea
The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Sea in the north. It is more than long and wide, covering . It hosts key north European shipping lanes and is a major fishery. The coast is a popular destination for recreation and tourism in bordering countries, and a rich source of energy resources, including wind energy, wind and wave power. The North Sea has featured prominently in geopolitical and military affairs, particularly in Northern Europe, from the Middle Ages to the modern era. It was also important globally through the power northern Europeans projected worldwide during much of the Middle Ages and into the modern era. The North Sea was the centre of the Viking Age, Vikings' rise. The Hanseatic League, the Dutch Golden Age, Dutch Republic, and Kingdom of Great Britain, Brita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The World Wonders
"The world wonders" is a phrase which rose to notoriety following its use during World War II when it appeared as part of a decoded message sent by Fleet Admiral Chester Nimitz, Commander in Chief, U.S. Pacific Fleet, to Admiral William Halsey Jr. William Frederick "Bull" Halsey Jr. (30 October 1882 – 16 August 1959) was an American Navy admiral during World War II. He is one of four officers to have attained the rank of five-star fleet admiral of the United States Navy, the others be ... at the height of the Battle of Leyte Gulf on October 25, 1944. The words, intended to be without meaning, were added as padding (cryptography), security padding in an encryption, encrypted message to hinder Japanese attempts at cryptanalysis, but were mistakenly included in the decoded text given to Halsey. Halsey interpreted the phrase as a harsh and sarcastic rebuke, and as a consequence dropped his futile pursuit of a decoy Japanese carrier task force, and, belatedly, reversed some of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russian Copulation
Russian(s) may refer to: *Russians (), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries *A citizen of Russia *Russian language, the most widely spoken of the Slavic languages *''The Russians'', a book by Hedrick Smith *Russian (comics), fictional Marvel Comics supervillain from ''The Punisher'' series *Russian (solitaire), a card game * "Russians" (song), from the album ''The Dream of the Blue Turtles'' by Sting *"Russian", from the album ''Tubular Bells 2003'' by Mike Oldfield *"Russian", from the album '' '' by Caravan Palace *Nik Russian, the perpetrator of a con committed in 2002 See also * *Russia (other) *Rus (other) *Rossiysky (other) Rossiysky (masculine), Rossiyskaya (feminine), or Rossiyskoye (neuter), all meaning ''Russian Federation, Russian'', may refer to: *Rossiysky, Orenburg Oblast, a rural locality (a settlement) in Orenburg Oblast, Russia *Rossiysky, Rostov Oblast, a r ... * Russian River ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-UCO
The 5-UCO (5-Unit Controlled)Ralph Erskine, "The 1944 Naval BRUSA Agreement and its Aftermath", ''Cryptologia'' 30(1), January 2006 pp14–15 was an on-line one-time tape Vernam cipher encryption system developed by the UK during World War II for use on teleprinter circuits. During the 1950s, it was used by the UK and the US for liaison on cryptanalysis. 5-UCO was fully synchronous, and therefore could be electrically regenerated on tandem high frequency (HF) radio links (i.e. one link connected to the next). It could operate directly with commercial circuits. The system also provided traffic-flow security (TFS). Another feature of the 5-UCO was that the receiving operator could maintain synchronisation if the path delay suddenly changed by "walking up and down" the key tape (one character at a time or one bit at a time). This procedure avoided the cumbersome task of a restart.Melville Klein, "Securing Record Communications: The TSEC/KW-26", 2003, NSA brochure, p. 4(PDF)/ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
One-time Tape
The one-time pad (OTP) is an encryption technique that cannot be cracked in cryptography. It requires the use of a single-use pre-shared key that is larger than or equal to the size of 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 is 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 truly random. # The key must never be reused in whole or in part. # The key must be kept completely secret by the communicating parties. These requirements make the OTP the only known encryption system that is mathematically proven to be unbreakable under the principles of information theory. Digital versions of one-time pad ciphers have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Władysław Kozaczuk
Władysław Kozaczuk (23 December 1923 – 26 September 2003) was a Polish Army colonel and a military and intelligence historian. Life Born in the village of Babiki near Sokółka, Kozaczuk joined the army in 1944, during World War II, at Białystok. In 1945 he became a Polish Army second lieutenant, and spent the first five years of his service commanding operational units of the Internal Security Corps, fighting the Polish anticommunist underground and then the Ukrainian Insurgent Army. In 1950 he was transferred to the Internal Security Corps Staff in Warsaw. In 1954–55, following the Korean War, Kozaczuk carried out armistice-related duties in Korea. In 1955–58 he served in the Polish Ministry of Internal Affairs ('). In 1957–58 he saw duty with the International Control Commission in Vietnam. In 1958–69 he served in Polish military counter-intelligence ('' Wojskowa Służba Wewnętrzna''). According to his family, he found conditions the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marian Rejewski
Marian Adam Rejewski (; 16 August 1905 – 13 February 1980) was a Polish people, Polish mathematician and Cryptography, cryptologist who in late 1932 reconstructed the sight-unseen German military Enigma machine, Enigma cipher machine, aided by limited documents obtained by French secret service, French military intelligence. Over the next nearly seven years, Rejewski and fellow mathematician-cryptologists Jerzy Różycki and Henryk Zygalski, working at the Polish General Staff's Cipher Bureau (Poland), Cipher Bureau, developed techniques and equipment for decrypting the Enigma ciphers, even as the Germans introduced modifications to their Enigma machines and encryption procedures. Rejewski's contributions included the card catalog (cryptology), cryptologic card catalog and the cryptologic bomb. Five weeks before the European theatre of World War II, outbreak of World War II in Europe, the Poles shared their achievements with French and British counterparts who had made n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biuro Szyfrów
The Cipher Bureau ( Polish: ''Biuro Szyfrów'', ) was the interwar Polish General Staff's Second Department's unit charged with SIGINT and both cryptography (the ''use'' of ciphers and codes) and cryptanalysis (the ''study'' of ciphers and codes, for the purpose of "breaking" them). The precursor of the agency that would become the Cipher Bureau was created in May 1919, during the Polish-Soviet War (1919–1921), and played a vital role in securing Poland's survival and victory in that war. In mid-1931, the Cipher Bureau was formed by the merger of pre-existing agencies. In December 1932, the Bureau began breaking Germany's Enigma ciphers. Over the next seven years, Polish cryptologists overcame the growing structural and operating complexities of the plugboard-equipped Enigma. The Bureau also broke Soviet cryptography. Five weeks before the outbreak of World War II, on 25 July 1939, in Warsaw, the Polish Cipher Bureau revealed its Enigma-decryption techniques and equipmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alan Turing
Alan Mathison Turing (; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher and theoretical biologist. He was highly influential in the development of theoretical computer science, providing a formalisation of the concepts of algorithm and computation with the Turing machine, which can be considered a model of a general-purpose computer. Turing is widely considered to be the father of theoretical computer science. Born in London, Turing was raised in southern England. He graduated from University of Cambridge, King's College, Cambridge, and in 1938, earned a doctorate degree from Princeton University. During World War II, Turing worked for the Government Code and Cypher School at Bletchley Park, Britain's codebreaking centre that produced Ultra (cryptography), Ultra intelligence. He led Hut 8, the section responsible for German naval cryptanalysis. Turing devised techniques for speeding the breaking of Germ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double-Cross System
The Double-Cross System or XX System was a World War II counter-espionage and deception operation of the British Security Service ( MI5). Nazi agents in Britain – real and false – were captured, turned themselves in or simply announced themselves, and were then used by the British to broadcast mainly disinformation to their Nazi controllers. Its operations were overseen by the Twenty Committee under the chairmanship of John Cecil Masterman; the name of the committee comes from the number 20 in Roman numerals: "XX" (i.e. a double cross). The policy of MI5 during the war was initially to use the system for counter-espionage. It was only later that its potential for deception purposes was realised. Of the agents from the German intelligence services, ''Abwehr'' and '' Sicherheitsdienst'' (SD), while many who reached British shores turned themselves in to the authorities, others were apprehended after they made elementary mistakes during their operations. In addition, some were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
