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Vigenère Cipher
The Vigenère cipher () is a method of encryption, encrypting alphabetic text where each letter of the plaintext is encoded with a different Caesar cipher, whose increment is determined by the corresponding letter of another text, the key (cryptography), key. For example, if the plaintext is attacking tonight and the key is oculorhinolaryngology, then *the first letter of the plaintext, a, is shifted by 14 positions in the alphabet (because the first letter of the key, o, is the 14th letter of the alphabet, counting from zero), yielding o; *the second letter, t, is shifted by 2 (because the second letter of the key, c, is the 2nd letter of the alphabet, counting from zero) yielding v; *the third letter, t, is shifted by 20 (u), yielding n, with wrap-around; and so on. It is important to note that traditionally spaces and punctuation are removed prior to encryption and reintroduced afterwards. * In this example the tenth letter of the plaintext t is shifted by 14 position ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Autokey Cipher
An autokey cipher (also known as the autoclave cipher) is a cipher that incorporates the message (the plaintext) into the key. The key is generated from the message in some automated fashion, sometimes by selecting certain letters from the text or, more commonly, by adding a short ''primer key'' to the front of the message. There are two forms of autokey cipher: ''key-autokey'' and ''text-autokey'' ciphers. A key-autokey cipher uses previous members of the keystream to determine the next element in the keystream. A text-autokey uses the previous message text to determine the next element in the keystream. History This cipher was invented in 1586 by Blaise de Vigenère with a reciprocal table of ten alphabets. Vigenère's version used an agreed-upon letter of the alphabet as a primer, making the key by writing down that letter and then the rest of the message. More popular autokeys use a tabula recta, a square with 26 copies of the alphabet, the first line starting with 'A', th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Gilbert Vernam
Gilbert Sandford Vernam (April 3, 1890 – February 7, 1960) was a Worcester Polytechnic Institute 1914 graduate and AT&T Bell Labs engineer who, in 1917, invented an additive polyalphabetic stream cipher and later co-invented an automated one-time pad cipher. Vernam proposed a teleprinter cipher in which a previously prepared key, kept on paper tape, is combined character by character with the plaintext message to produce the ciphertext. To decipher the ciphertext, the same key would be again combined character by character, producing the plaintext. Vernam later worked for the Postal Telegraph Company, and became an employee of Western Union when that company acquired Postal in 1943. His later work was largely with automatic switching systems for telegraph networks. Vernam's patent The combining function Vernam specified in , issued July 22, 1919, is the XOR operation, applied to the individual impulses or bits used to encode the characters in the Baudot code. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
One-time Pad
The one-time pad (OTP) is an encryption technique that cannot be Cryptanalysis, 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 (cryptography), 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 arithmetic, 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 True random, 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 informat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
American Civil War
The American Civil War (April 12, 1861May 26, 1865; also known by Names of the American Civil War, other names) was a civil war in the United States between the Union (American Civil War), Union ("the North") and the Confederate States of America, Confederacy ("the South"), which was formed in 1861 by U.S. state, states that had Secession in the United States, seceded from the Union. The Origins of the American Civil War, central conflict leading to war was a dispute over whether Slavery in the United States, slavery should be permitted to expand into the western territories, leading to more slave states, or be prohibited from doing so, which many believed would place slavery on a course of ultimate extinction. Timeline of events leading to the American Civil War, Decades of controversy over slavery came to a head when Abraham Lincoln, who opposed slavery's expansion, won the 1860 presidential election. Seven Southern slave states responded to Lincoln's victory by seceding f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Confederate States Of America
The Confederate States of America (CSA), also known as the Confederate States (C.S.), the Confederacy, or Dixieland, was an List of historical unrecognized states and dependencies, unrecognized breakaway republic in the Southern United States from 1861 to 1865. It comprised eleven U.S. states that declared Secession in the United States, secession: South Carolina in the American Civil War, South Carolina, Mississippi in the American Civil War, Mississippi, Florida in the American Civil War, Florida, Alabama in the American Civil War, Alabama, Georgia in the American Civil War, Georgia, Louisiana in the American Civil War, Louisiana, Texas in the American Civil War, Texas, Virginia in the American Civil War, Virginia, Arkansas in the American Civil War, Arkansas, Tennessee in the American Civil War, Tennessee, and North Carolina in the American Civil War, North Carolina. These states fought against the United States during the American Civil War. With Abraham Lincoln's 1860 Un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cryptographic Sliding Rule-IMG 0533
Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adversarial behavior. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, information security, electrical engineering, digital signal processing, physics, and others. Core concepts related to information security ( data confidentiality, data integrity, authentication, and non-repudiation) are also central to cryptography. Practical applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymous with encryption, converting re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Random House
Random House is an imprint and publishing group of Penguin Random House. Founded in 1927 by businessmen Bennett Cerf and Donald Klopfer as an imprint of Modern Library, it quickly overtook Modern Library as the parent imprint. Over the following decades, a series of acquisitions made it into one of the largest publishers in the United States. In 2013, it was merged with Penguin Group to form Penguin Random House, which is owned by the Germany-based media conglomerate Bertelsmann. Penguin Random House uses its brand for Random House Publishing Group and Random House Children's Books, as well as several imprints. Company history 20th century Random House was founded in 1927 by Bennett Cerf and Donald Klopfer, two years after they acquired the Modern Library imprint from publisher Horace Liveright, which reprints classic works of literature. Cerf is quoted as saying, "We just said we were going to publish a few books on the side at random", which suggested the name Random ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Anchor Books
Vintage Books is a trade paperback publishing imprint of Penguin Random House originally established by Alfred A. Knopf in 1954. The company was acquired by Random House in April 1960, and a British division was set up in 1990. After Random House merged with Bantam Doubleday Dell, Doubleday's Anchor Books trade paperback line was added to the same division as Vintage. Following Random House's merger with Penguin, Vintage UK was transferred to Penguin UK. In addition to publishing classic and contemporary works in paperback under the Vintage brand, the imprint also oversees the sub-imprints Bodley Head, Jonathan Cape, Chatto and Windus, Harvill Secker, Hogarth Press, Square Peg, and Yellow Jersey. Vintage began publishing some titles in the mass-market paperback format in 2003. Notable authors * Albert Camus * Robert Caro * Joan Didion * Dave Eggers * Ralph Ellison * James Ellroy * William Faulkner * Dashiell Hammett * Jane Jacobs * Gabriel Garcia Marquez * Cormac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Charles Babbage
Charles Babbage (; 26 December 1791 – 18 October 1871) was an English polymath. A mathematician, philosopher, inventor and mechanical engineer, Babbage originated the concept of a digital programmable computer. Babbage is considered by some to be "List of pioneers in computer science, father of the computer". He is credited with inventing the first mechanical computer, the difference engine, that eventually led to more complex electronic designs, though all the essential ideas of modern computers are to be found in his analytical engine, programmed using a principle openly borrowed from the Jacquard loom. As part of his computer work, he also designed the first Printer (computing), computer printers. He had a broad range of interests in addition to his work on computers covered in his 1832 book ''Economy of Manufactures and Machinery''. He was an important figure in the social scene in London, and is credited with importing the "scientific soirée" from France with hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Scientific American
''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it, with more than 150 Nobel Prize-winners being featured since its inception. In print since 1845, it is the oldest continuously published magazine in the United States. ''Scientific American'' is owned by Springer Nature, which is a subsidiary of Holtzbrinck Publishing Group. History ''Scientific American'' was founded by inventor and publisher Rufus Porter (painter), Rufus Porter in 1845 as a four-page weekly newspaper. The first issue of the large-format New York City newspaper was released on August 28, 1845. Throughout its early years, much emphasis was placed on reports of what was going on at the United States Patent and Trademark Office, U.S. Patent Office. It also reported on a broad range of inventions including perpetual motion machines, an 1860 devi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
The Alphabet Cipher
"The Alphabet Cipher" was a brief study published by Lewis Carroll in 1868, describing how to use the alphabet to send encrypted codes. It was one of four ciphers he invented between 1858 and 1868, and one of two polyalphabetic ciphers he devised during that period and used to write letters to his friends. It describes what is known as a Vigenère cipher, a well-known scheme in cryptography. While Carroll calls this cipher "unbreakable", Friedrich Kasiski had already published in 1863 a volume describing how to break such ciphers and Charles Babbage had secretly found ways to break polyalphabetic ciphers in the previous decade during the Crimean War. The piece begins with a tabula recta In cryptography, the ''tabula recta'' (from Latin language, Latin ''wikt:tabula#Latin, tabula wikt:rectus#Latin, rēcta'') is a square table of alphabets, each row of which is made by shifting the previous one to the left. The term was invented .... "The Alphabet-Cipher", Lewis Carroll, 1868 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
