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Nihilist Cipher
In the history of cryptography, the Nihilist cipher is a manually operated symmetric encryption cipher, originally used by Russian Nihilists in the 1880s to organize terrorism against the tsarist regime. The term is sometimes extended to several improved algorithms used much later for communication by the First Chief Directorate with its spies. Description First the encipherer constructs a Polybius square using a mixed alphabet. This is used to convert both the plaintext and a keyword to a series of two digit numbers. These numbers are then added together in the normal way to get the ciphertext, with the key numbers repeated as required. Example Consider the Polybius square created using the keyword ZEBRAS: with a plaintext of "DYNAMITE WINTER PALACE" and a key of RUSSIAN. This expands to: PT: 23 55 41 15 35 32 45 12 53 32 41 45 12 14 43 15 34 15 22 12 KEY: 14 51 21 21 32 15 41 14 51 21 21 32 15 41 14 51 21 21 32 15 CT: 37 106 62 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Cryptography
Cryptography, the use of codes and ciphers to protect secrets, began thousands of years ago. Until recent decades, it has been the story of what might be called classical cryptography — that is, of methods of encryption that use pen and paper, or perhaps simple mechanical aids. In the early 20th century, the invention of complex mechanical and electromechanical machines, such as the Enigma rotor machine, provided more sophisticated and efficient means of encryption; and the subsequent introduction of electronics and computing has allowed elaborate schemes of still greater complexity, most of which are entirely unsuited to pen and paper. The development of cryptography has been paralleled by the development of cryptanalysis — the "breaking" of codes and ciphers. The discovery and application, early on, of frequency analysis to the reading of encrypted communications has, on occasion, altered the course of history. Thus the Zimmermann Telegram triggered the United States' en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans Japanese archipelago, an archipelago of List of islands of Japan, 6852 islands covering ; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa Island, Okinawa. Tokyo is the Capital of Japan, nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto. Japan is the List of countries and dependencies by population, eleventh most populous country in the world, as well as one of the List of countries and dependencies by population density, most densely populated and Urbanization by country, urbanized. About three-fourths of Geography of Japan, the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Topics In Cryptography
The following outline is provided as an overview of and topical guide to cryptography: Cryptography (or cryptology) – practice and study of hiding information. Modern cryptography intersects the disciplines of mathematics, computer science, and engineering. Applications of cryptography include ATM cards, computer passwords, and electronic commerce. Essence of cryptography * Cryptographer * Encryption/decryption * Cryptographic key * Cipher * Ciphertext * Plaintext * Code * Tabula recta * Alice and Bob Uses of cryptographic techniques * Commitment schemes * Secure multiparty computation * Electronic voting * Authentication * Digital signatures * Crypto systems * Dining cryptographers problem * Anonymous remailer * Pseudonymity * Onion routing * Digital currency * Secret sharing * Indistinguishability obfuscation Branches of cryptography * Multivariate cryptography * Post-quantum cryptography * Quantum cryptography * Steganography * Visual cryptography History ... [...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] |
Reino Häyhänen
Reino Häyhänen (; 14 May 1920 – 17 February 1961) was a Soviet intelligence officer of the KGB who defected from the Soviet Union to the United States in May 1957. Häyhänen surrendered information on Soviet espionage activities that solved the Hollow Nickel Case for the FBI, and led to the arrest of his KGB partner Rudolf Abel and other Soviet spies in the United States and Canada. Early life Reino Häyhänen born on 14 May 1920 in the village of Kaskisaari in Saint Petersburg Governorate, Russian Soviet Federative Socialist Republic, into an Ingrian Finnish peasant family. Häyhänen rose above his modest background to become an honor student and, in 1939, obtained the equivalent of a certificate to teach in high school, and in September was appointed to the faculty of a primary school in the village of Lipitsy. However, two months later, Häyhänen was conscripted by the NKVD, the secret police of the Soviet Union, following the Soviet invasion of Finland starting the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VIC Cipher
Vic (; es, Vic or Pancracio Celdrán (2004). Diccionario de topónimos españoles y sus gentilicios (5ª edición). Madrid: Espasa Calpe. p. 843. ISBN 978-84-670-3054-9. «Vic o Vich (viquense, vigitano, vigatán, ausense, ausetano, ausonense): Ciudad barcelonesa, cabeza del partido judicial situada cerca de los ríos Ter y Méder, en la Plana de Vich.») is the capital of the ''comarca'' of Osona, in the province of Barcelona, Catalonia, Spain. Vic is located from Barcelona and from Girona. Geography Vic lies in the middle of the Plain of Vic, equidistant from Barcelona and the Pyrenees. Vic has persistent fog in winter as a result of a thermal inversion, with temperatures as low as -10 °C, an absolute record of -24 °C and episodes of cold and severe snowstorms. For this reason the natural vegetation includes the pubescent oak typical of the sub-Mediterranean climates of eastern France, Northern Italy and the Balkans. Names Originally known as ''Auso'', it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Good Soldier Švejk
''The Good Soldier Švejk'' () is an unfinished satirical dark comedy novel by Czech writer Jaroslav Hašek, published in 1921–1923, about a good-humored, simple-minded, middle-aged man who pretends to be enthusiastic to serve Austria-Hungary in World War I. ''The Good Soldier Švejk'' is the abbreviated title; the original Czech title of the work is ''Osudy dobrého vojáka Švejka za světové války'', literally ''The Fateful Adventures of the Good Soldier Švejk During the World War''. The book is the most translated novel of Czech literature, having been translated into over 50 languages. Publication Hašek originally intended ''Švejk'' to cover a total of six volumes, but had completed only three (and started on the fourth) upon his death from heart failure on January 3, 1923. The novel as a whole was originally illustrated (after Hašek's death) by Josef Lada and more recently by Czech illustrator Petr Urban. The volumes are: # ''Behind the Lines'' (''V zázemí'', 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benford's Law
Benford's law, also known as the Newcomb–Benford law, the law of anomalous numbers, or the first-digit law, is an observation that in many real-life sets of numerical data, the leading digit is likely to be small.Arno Berger and Theodore P. HillBenford's Law Strikes Back: No Simple Explanation in Sight for Mathematical Gem 2011. In sets that obey the law, the number 1 appears as the leading significant digit about 30% of the time, while 9 appears as the leading significant digit less than 5% of the time. If the digits were distributed uniformly, they would each occur about 11.1% of the time. Benford's law also makes predictions about the distribution of second digits, third digits, digit combinations, and so on. The graph to the right shows Benford's law for base 10, one of infinitely many cases of a generalized law regarding numbers expressed in arbitrary (integer) bases, which rules out the possibility that the phenomenon might be an artifact of the base-10 number syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Direction Finder
Direction finding (DF), or radio direction finding (RDF), isin accordance with International Telecommunication Union (ITU)defined as radio location that uses the reception of radio waves to determine the direction in which a radio station or an object is located. This can refer to radio or other forms of wireless communication, including radar signals detection and monitoring (ELINT/ESM). By combining the direction information from two or more suitably spaced receivers (or a single mobile receiver), the source of a transmission may be located via triangulation. Radio direction finding is used in the navigation of ships and aircraft, to locate emergency transmitters for search and rescue, for tracking wildlife, and to locate illegal or interfering transmitters. RDF was important in combating German threats during both the World War II Battle of Britain and the long running Battle of the Atlantic. In the former, the Air Ministry also used RDF to locate its own fighter group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unicity Distance
In cryptography, unicity distance is the length of an original ciphertext needed to break the cipher by reducing the number of possible spurious keys to zero in a brute force attack. That is, after trying every possible key, there should be just one decipherment that makes sense, i.e. expected amount of ciphertext needed to determine the key completely, assuming the underlying message has redundancy. Claude Shannon defined the unicity distance in his 1949 paper " Communication Theory of Secrecy Systems". Consider an attack on the ciphertext string "WNAIW" encrypted using a Vigenère cipher with a five letter key. Conceivably, this string could be deciphered into any other string—RIVER and WATER are both possibilities for certain keys. This is a general rule of cryptanalysis: with no additional information it is impossible to decode this message. Of course, even in this case, only a certain number of five letter keys will result in English words. Trying all possible keys we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Straddling Checkerboard
A straddling checkerboard is a device for converting an alphanumeric plaintext into digits whilst simultaneously achieving fractionation (a simple form of information diffusion) and data compression relative to other schemes using digits. It also is known as a monôme-binôme cipher. History In 1555, Pope Paul IV created the office of Cipher Secretary to the Pontiff. In the late 1580s, this position was held by members of the Argenti family, most notably Giovanni Batista and his nephew, Matteo. Matteo was the first to intentionally obscure borders between one-digit and two-digit codes, designing the first variable length cipher, although this was still a substitution cipher: With that cipher, ''La vigilanza di papa Clemente fu grande in ogni genere de negotii'' was enciphered as 550365178370360088658074864865534032402000824315833060080257009830075583200230258020028390875. The following table rearranges the same key so that the column number corresponds to the second digit and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Orchestra (spy)
The Red Orchestra (german: Die Rote Kapelle, ), as it was known in Germany, was the name given by the Abwehr Section III.F to anti-Nazi resistance workers in August 1941. It primarily referred to a loose network of resistance groups, connected through personal contacts, uniting hundreds of opponents of the Nazi regime. These included groups of friends who held discussions that were centred on Harro Schulze-Boysen, Adam Kuckhoff and Arvid Harnack in Berlin, alongside many others. They printed and distributed prohibited leaflets, posters, and stickers, hoping to incite civil disobedience. They aided Jews and resistance to escape the regime, documented the atrocities of the Nazis, and transmitted military intelligence to the Allies. Contrary to legend, the Red Orchestra was neither directed by Soviet communists nor under a single leadership. It was a network of groups and individuals, often operating independently. To date, about 400 members are known by name. The term was also u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
