Kasiski enlisted in East Prussia's 33rd Infantry Regiment on 20 March 1823 at the age of 17. In May 1824, he was promoted to the rank of Master Sergeant, and eight months later was commissioned as a Second Lieutenant in February 1825. It took fourteen years to earn his next promotion, when, in May 1839, he advanced to the rank of First Lieutenant. His next advancement was quicker, promoted to Captain in November 1842. Kasiski finally retired from active service with the rank of Major on 17 February 1852. Between 1860 and 18 ...

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Friedrich Kasiski, Friedrich Kasiski - Military service, Friedrich Kasiski - Cryptography

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Charles Babbage (December 26, 1791 – October 18, 1871) was an English mathematician, analytical philosopher, mechanical engineer and (proto-) computer scientist who originated the idea of a programmable computer. Parts of his uncompleted mechanisms are on display in the London Science Museum. In 1991, working from Babbage's original plans, a difference engine was completed, and functioned perfectly. It was built to tolerances achievable in the 19th century, indicating that Babbage's machine would have worked. Nine years later ...

Including:

• Charles Babbage - Life
• Charles Babbage - Education
• Charles Babbage - Marriage
• Charles Babbage - Children
• Charles Babbage - Design of computers
• Charles Babbage - Difference engine
• Charles Babbage - Printer
• Charles Babbage - Analytical engine
• Charles Babbage - Other accomplishments
• Charles Babbage - Odd

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Cryptography List of cryptographers - Pre-computer. Charles Babbage, UK, 19th century mathematician who, about the time of the Crimean War, secretly developed an effective attack against polyalphabetic substitution ciphers. His development was published independently a few years later by Friedrich Kasiski, a Prussian officer. Babbage also designed, and had partially built, the first programmable digital computer, the Analytical Engine. He first designed and had partially bui ...

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• List of cryptographers - Pre-19th century
• List of cryptographers - Pre-computer
• List of cryptographers - Modern
• List of cryptographers - External link

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The Vigenère cipher is a method of encryption that uses a series of different Caesar ciphers based on the letters of a keyword. It is a simple form of polyalphabetic substitution. The Vigenère cipher has been reinvented many times. The method was originally described by Giovan Batista Belaso in his 1553 book La cifra del. Sig. Giovan Batista Belaso, however, the scheme was later misattributed to Blaise de Vigenère in the 19th cent ...

Including:

• Vigenère cipher - History
• Vigenère cipher - Description
• Vigenère cipher - Cryptanalysis
• Vigenère cipher - Kasiski examination
• Vigenère cipher - Friedman test
• Vigenère cipher - The cipher of Blaise de Vigenère
• Vigenère cipher - Variants
• Vigenère cipher - Notes

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Charles Babbage was born in England most likely at 44 Crosby Row, Walworth Road, London. There is quite a discrepancy over the date of Babbage's birth. It was first published in The Times obituary as December 26, 1792. However, days later a nephew of Babbage wrote to say that Babbage was born precisely one year earlier, in 1791. Later evidence, from St. Mary's Newington, London, proved that Babbage was born on January 6, 1792. The reliabi ...

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Charles Babbage, Charles Babbage - Life, Charles Babbage - Education, Charles Babbage - Marriage, Charles Babbage - Children, Charles Babbage - Design of computers, Charles Babbage - Difference engine, Charles Babbage - Printer, Charles Babbage - Analytical engine, Charles Babbage - Other accomplishments, Charles Babbage - Odd

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Substitution over a single letter—simple substitution—can be demonstrated by writing out the alphabet in some order to represent the substitution. This is termed a substitution alphabet. The cipher alphabet may be shifted or reversed (creating the Caesar and Atbash ciphers, respectively) or scrambled in a more complex fashion, in which case it is called a mixed alphabet or deranged alphabet. Traditionally, mixed alphabets are created by first writing out a keyword, then all the remaining letters. Substitution cipher - Examples. Using this system, the ...

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Substitution cipher, Substitution cipher - Simple substitution, Substitution cipher - Examples, Substitution cipher - Security for simple substitution ciphers, Substitution cipher - Homophonic substitution, Substitution cipher - Polyalphabetic substitution, Substitution cipher - Polygraphic substitution, Substitution cipher - Mechanical substitution ciphers, Substitution cipher - The one-time pad, Substitution cipher - Substitution in modern cryptography

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The strength behind the Vigenère cipher is, like all polyalphabetic ciphers, to make frequency analysis more difficult. Frequency analysis is the practice of decrypting a message by counting the frequency of ciphertext letters, and equating it to the letter frequency of normal text. For instance if P occurred most in a ciphertext whose plaintext is in English one could suspect that P corresponded to E, because E is the most frequently used letter in English. Using the Vigenère cipher, E can be enciphered as any of several letters in the alphabet at different points in the ...

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Vigenère cipher, Vigenère cipher - History, Vigenère cipher - Description, Vigenère cipher - Cryptanalysis, Vigenère cipher - Kasiski examination, Vigenère cipher - Friedman test, Vigenère cipher - The cipher of Blaise de Vigenère, Vigenère cipher - Variants, Vigenère cipher - Notes

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An early example of a book about cryptography was a Roman work, now lost and known only by references. Many of the early works on cryptography were esoteric, mystical, and reputation-promoting; cryptography being mysterious, there was much opportunity for such things. At least one work by Trithemius was put on the Index (ie, banned) by the Catholic Church as being about black magic or witchcraft. Many writers claimed to have invented unbreakable ciphers. None were, t ...

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Books on cryptography, Books on cryptography - Early history, Books on cryptography - Open literature versus classified literature, Books on cryptography - The Codebreakers, Books on cryptography - Early 21st-century conditions, Books on cryptography - The list, Books on cryptography - Cryptographic techniques, Books on cryptography - Cryptographic environment/context -- 'security', Books on cryptography - History of cryptography, Books on cryptography - Historic works, Books on cryptography - Overview of cryptography, Books on cryptography - Fiction

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Rotor machine - Invention. The concept of a rotor machine occurred to a number of inventors independently at a similar time. In 2003, it emerged that the first inventors were two Dutch naval officers, Theo A. van Hengel (1875 – 1939) and R. P. C. Spengler (1875 – 1955) in 1915 (De Leeuw, 2003). Previously, the invention had been ascribed to four inventors working independently and at much the same time: Edward Hebern, Ar ...

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Rotor machine, Rotor machine - Background, Rotor machine - Mechanization, Rotor machine - History, Rotor machine - Invention, Rotor machine - The Enigma machine, Rotor machine - Various machines, Rotor machine - List of rotor machines

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In recognition of the high error rate in the calculation of mathematical tables, Babbage wanted to find a method by which they could be calculated mechanically, removing human sources of error. Three different factors seem to have influenced him: a dislike of untidiness; his experience working on logarithmic tables; and existing work on calculating machines carried out by Wilhelm Schickard, Blaise Pascal, and Gottfried Leibniz. He first discussed the principles of a calcu ...

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Charles Babbage, Charles Babbage - Life, Charles Babbage - Education, Charles Babbage - Marriage, Charles Babbage - Children, Charles Babbage - Design of computers, Charles Babbage - Difference engine, Charles Babbage - Printer, Charles Babbage - Analytical engine, Charles Babbage - Other accomplishments, Charles Babbage - Odd

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History of cryptography - Shannon. The era of modern cryptography really begins with Claude Shannon, arguably the father of mathematical cryptography. In 1949 he published the paper Communication Theory of Secrecy Systems in the Bell System Technical Journal and a little later the book, Mathematical Theory of Communication, with Warren Weaver. These, in addition to his other works on information and communication theory established a solid theoretical basis for cryptography and for cryptanalysis. And with that, c ...

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History of cryptography, History of cryptography - Classical cryptography, History of cryptography - Medieval cryptography, History of cryptography - Cryptography from 1800 to World War II, History of cryptography - World War II cryptography, History of cryptography - Modern cryptography, History of cryptography - Shannon, History of cryptography - An encryption standard, History of cryptography - Public key, History of cryptography - Cryptography politics, History of cryptography - Modern cryptanalysis

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The strength behind the Vigenère cipher is, like all polyalphabetic ciphers, to make frequency analysis more difficult. Frequency analysis is the practice of decrypting a message by counting the frequency of ciphertext letters, and equating it to the letter frequency of normal text. For instance if P occurred most in a ciphertext whose plaintext is in English one could suspect that P corresponded to E, because E is the most frequently used letter in English. Using the Vigenère cipher, E can be enciphered as any of several letters in the alphabet at different points in the ...

See also:

Vigenère cipher, Vigenère cipher - History, Vigenère cipher - Description, Vigenère cipher - Cryptanalysis, Vigenère cipher - Kasiski examination, Vigenère cipher - Friedman test, Vigenère cipher - Variants, Vigenère cipher - Notes

Read more here: » Vigenère cipher: Encyclopedia II - Vigenère cipher - Cryptanalysis

It is relatively straightforward to create a machine for performing simple substitution. We can consider an electrical system with 26 switches attached to 26 light bulbs; when you turn on any one of the switches, one of the light bulbs is illuminated. If each switch is operated by a key on a typewriter, and the bulbs are labelled with letters, then such a system can be used for encryption by choosing the wiring between the keys and the bulb: for example, typing the letter A would make the bulb labelled Q light up. However, ...

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Rotor machine, Rotor machine - Background, Rotor machine - Mechanization, Rotor machine - History, Rotor machine - Invention, Rotor machine - The Enigma machine, Rotor machine - Various machines, Rotor machine - List of rotor machines

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In classical cryptography, one of the earliest encryption methods was the simple substitution cipher, where letters in a message were systematically replaced using some secret scheme. Monoalphabetic substitution ciphers used only a single replacement scheme — sometimes termed an "alphabet"; this could be easily broken, for example, by using frequency analysis. Somewhat more secure were schemes involving multiple alphabets, polyalphabetic ciphers. Because such schemes were implemented by hand, only a handful of different alphabets co ...

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Rotor machine, Rotor machine - Background, Rotor machine - Mechanization, Rotor machine - History, Rotor machine - Invention, Rotor machine - The Enigma machine, Rotor machine - Various machines, Rotor machine - List of rotor machines

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With the invention of radio, much of military communications went wireless, allowing the possiblity of enemy interception much more readily than tapping into a landline, increasing the need to protect communications using sufficiently strong cryptography. By the end of World War I, cryptography and its literature began to be both 'official', and 'classified'. Thereupon, publicly available material started to diverge more than before from actual cryptographic, and cryptanalytic, practice, largely by 'leaving things out'. There began a ...

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Books on cryptography, Books on cryptography - Early history, Books on cryptography - Open literature versus classified literature, Books on cryptography - The Codebreakers, Books on cryptography - Early 21st-century conditions, Books on cryptography - The list, Books on cryptography - Cryptographic techniques, Books on cryptography - Cryptographic environment/context -- 'security', Books on cryptography - History of cryptography, Books on cryptography - Historic works, Books on cryptography - Overview of cryptography, Books on cryptography - Fiction

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The running key variant of the Vigenère cipher was also considered unbreakable at one time. This version uses a block of text as long as plaintext as the key. Since the key is as long as the message the Friedman and Kassiski tests no longer work (the key is not repeated). In 1920, Friedman was the first to discover this variant's weaknesses. The problem with the running key Vigenere cipher is that the cryptanalyst has statistical information about the key (assuming that the block of text is in English) and that inf ...

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Vigenère cipher, Vigenère cipher - History, Vigenère cipher - Description, Vigenère cipher - Cryptanalysis, Vigenère cipher - Kasiski examination, Vigenère cipher - Friedman test, Vigenère cipher - Variants, Vigenère cipher - Notes

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In a Caesar cipher, each letter of the alphabet is shifted along some number of places; for example, in a Caesar cipher of shift 3, A would become D, B would become E and so on. The Vigenère cipher consists of using several Caesar ciphers in sequence with different shift values. To encipher, a table of alphabets can be used, termed a tabula recta, Vigenère square, or Vigenère table. It consists of the alphabet written out 26 times in different rows, each alphabet shifted cycl ...

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Vigenère cipher, Vigenère cipher - History, Vigenère cipher - Description, Vigenère cipher - Cryptanalysis, Vigenère cipher - Kasiski examination, Vigenère cipher - Friedman test, Vigenère cipher - Variants, Vigenère cipher - Notes

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Leone Battista Alberti (the inventor of polyalphabetic ciphers), Johannes Trithemius (in his works Poligraphia and Stegonographia) and Giovanni Battista Della Porta (in Magia Naturalis) all created important predecessors to the Vigenère cipher. Trithemius was the first person to introduce the tabula recta, but he provided no system for switching between cipher alphabets. The Vigenère cipher was originally described by Giovan Batista Belaso in his 1553 book La cifra del. Sig. Giovan Batista Belaso. Blaise ...

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Vigenère cipher, Vigenère cipher - History, Vigenère cipher - Description, Vigenère cipher - Cryptanalysis, Vigenère cipher - Kasiski examination, Vigenère cipher - Friedman test, Vigenère cipher - Variants, Vigenère cipher - Notes

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One type of substitution cipher, the one-time pad, is quite special. It was invented near the end of WWI by Gilbert Vernam and Joseph Mauborgne in the US. It was mathematically proved unbreakable by Claude Shannon, probably during WWII; his work was first published in the late 1940s. In its most common implementation, the one-time pad can be called a substitution cipher only from an unusual perspective; typically, the plaintext l ...

See also:

Substitution cipher, Substitution cipher - Simple substitution, Substitution cipher - Examples, Substitution cipher - Security for simple substitution ciphers, Substitution cipher - Homophonic substitution, Substitution cipher - Polyalphabetic substitution, Substitution cipher - Polygraphic substitution, Substitution cipher - Mechanical substitution ciphers, Substitution cipher - The one-time pad, Substitution cipher - Substitution in modern cryptography

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Charles Babbage was born in England, most likely at 44 Crosby Row, Walworth Road, London. There is quite a discrepancy over the date of Babbage's birth. It was first published in The Times obituary as December 26, 1792. However, days later a nephew of Babbage wrote to say that Babbage was born precisely one year earlier, in 1791. The parish register of St. Mary's Newington, London, shows that ...

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Charles Babbage, Charles Babbage - Life, Charles Babbage - Education, Charles Babbage - Marriage, Charles Babbage - Children, Charles Babbage - Design of computers, Charles Babbage - Difference engine, Charles Babbage - Printer, Charles Babbage - Analytical engine, Charles Babbage - Other accomplishments, Charles Babbage - Odd

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