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Alberti Cipher
The Alberti cipher, created in 1467 by Italian architect Leon Battista Alberti, was one of the first polyalphabetic ciphers. In the opening pages of his treatise ' he explained how his conversation with the papal secretary Leonardo Dati about a recently developed movable type printing press led to the development of his cipher wheel. Cipher disk Alberti's cipher disk embodies the first example of polyalphabetic substitution with mixed alphabets and variable periods This device, called ''Formula'', was made up of two concentric disks, attached by a common pin, which could rotate one with respect to the other. The larger one is called ''Stabilis'' tationary or fixed and the smaller one is called ''Mobilis'' ovable The circumference of each disk is divided into 24 equal cells. The outer ring contains one uppercase alphabet for plaintext and the inner ring has a lowercase mixed alphabet for ciphertext. The outer ring also includes the numbers 1 to 4 for the superencipherment of a co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alberti Cipher Disk
Alberti may refer to: Leon Battista Alberti, the Renaissance architect Places * Alberti Partido, a partido of Buenos Aires Province, Argentina * Alberti, Buenos Aires, the main town of the partido * Alberti (Buenos Aires Underground), a railway station Other uses * Alberti (surname) Alberti is an Italian surname that derives from the given name Alberto, Latin translation of Germanic Albert (given name), Albert. It may refer to: *Alberti (family), Florentine family *Achille Alberti (1860–1943), Italian sculptor *Aída Alberti ... * Alberti bass, a musical accompaniment figuration, usually in the left hand on a keyboard instrument * Alberti cipher, an early polyalphabetic cipher (late 15th century) * Alberti (family), Florentine political family See also * Albertis (other) * Albertoni, a surname * D'Albertis (other) {{disambiguation, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptanalysis
Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic security systems and gain access to the contents of encrypted messages, even if the cryptographic key is unknown. In addition to mathematical analysis of cryptographic algorithms, cryptanalysis includes the study of side-channel attacks that do not target weaknesses in the cryptographic algorithms themselves, but instead exploit weaknesses in their implementation. Even though the goal has been the same, the methods and techniques of cryptanalysis have changed drastically through the history of cryptography, adapting to increasing cryptographic complexity, ranging from the pen-and-paper methods of the past, through machines like the British Bombes and Colossus computers at Bletchley Park in World War II, to the mathematically advanced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Kahn (writer)
David Kahn (February 7, 1930 – January 23, 2024) was an American historian, journalist, and writer. He wrote extensively on the history of cryptography and military intelligence. Kahn's first published book, '' The Codebreakers - The Story of Secret Writing'' (1967), has been widely considered to be a definitive account of the history of cryptography. Biography David Kahn was born in New York City to Florence Abraham Kahn, a glass manufacturer, and Jesse Kahn, a lawyer, and grew up in Great Neck, NY on Long Island. Kahn said he traced his interest in cryptography to reading Fletcher Pratt's '' Secret and Urgent'' (1939) as a boy. Kahn was a founding editor of the '' Cryptologia'' journal. In 1969, Kahn married Susanne Fiedler; they divorced in 1994. They have two sons, Oliver and Michael.* Kahn attended Bucknell University. After graduation, he worked as a reporter at ''Newsday''. He also served as an editor at the ''International Herald Tribune'' in Paris in the 1960 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpen-Adria-Universität Klagenfurt
The University of Klagenfurt ( or ''Alpen-Adria-Universität Klagenfurt'', AAU) is a federal Austrian research university and the largest research and higher education institution in the state of Carinthia. It has its campus in Klagenfurt. Originally founded in 1970 and relaunched in 1993, the university today holds faculties of arts, humanities & education, management, economics & law, social sciences, and technical sciences. It is listed in the ARWU, THE, and QS global rankings and held rank 48 worldwide in THE's ''Young University Rankings'' 2021. The university has defined three research priority areas, ''Social Ecology'' (until 2018, transferred to BOKU Vienna), ''Networked and Autonomous Systems'', and ''Multiple Perspectives in Optimization'', with the former spawning three ERC Grants and the latter a ''doc.funds'' programme of the Austrian Science Fund. It has launched a new initiative, ''Humans in the Digital Age'' (HDA), in 2019, hosting an ERC Grant on cybersecuri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Analysis
In cryptanalysis, frequency analysis (also known as counting letters) is the study of the frequency of letters or groups of letters in a ciphertext. The method is used as an aid to breaking classical ciphers. Frequency analysis is based on the fact that, in any given stretch of written language, certain letters and combinations of letters occur with varying frequencies. Moreover, there is a characteristic distribution of letters that is roughly the same for almost all samples of that language. For instance, given a section of English language, , , and are the most common, while , , and are rare. Likewise, , , , and are the most common pairs of letters (termed ''bigrams'' or ''digraphs''), and , , , and are the most common repeats. The nonsense phrase " ETAOIN SHRDLU" represents the 12 most frequent letters in typical English language text. In some ciphers, such properties of the natural language plaintext are preserved in the ciphertext, and these patterns have the poten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency Distribution
In statistics, the frequency or absolute frequency of an Event (probability theory), event i is the number n_i of times the observation has occurred/been recorded in an experiment or study. These frequencies are often depicted graphically or tabular form. Types The cumulative frequency is the total of the absolute frequencies of all events at or below a certain point in an ordered list of events. The Empirical probability, relative frequency (or ''empirical probability'') of an event is the absolute frequency Normalizing constant, normalized by the total number of events: : f_i = \frac = \frac. The values of f_i for all events i can be plotted to produce a frequency distribution. In the case when n_i = 0 for certain i, pseudocounts can be added. Depicting frequency distributions A frequency distribution shows a summarized grouping of data divided into mutually exclusive classes and the number of occurrences in a class. It is a way of showing unorganized data notably to sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kasiski
Major Friedrich Wilhelm Kasiski (29 November 1805 – 22 May 1881) was a German infantry officer, cryptographer and archeologist. Kasiski was born in Schlochau, Kingdom of Prussia (now Człuchów, Poland). Military service 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 1868 he was the commander of a National Guard battalion. Cryptography In 1863, Kasiski published a 95-page book on cryptography, ''Die Geheimschriften und die Dechiffrir-Kunst'' (German, "Secret writing and the Art of Deciphering"). This was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Cipher
In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is ''encipherment''. To encipher or encode is to convert information into cipher or code. In common parlance, "cipher" is synonymous with "code (cryptography), code", as they are both a set of steps that encrypt a message; however, the concepts are distinct in cryptography, especially classical cryptography. Codes generally substitute different length strings of characters in the output, while ciphers generally substitute the same number of characters as are input. A code maps one meaning with another. Words and phrases can be coded as letters or numbers. Codes typically have direct meaning from input to key. Codes primarily function to save time. Ciphers are algorithmic. The given input must follow the cipher's process to be solved. Ciphers are commonly used to encrypt written info ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leon Battista Alberti
Leon Battista Alberti (; 14 February 1404 – 25 April 1472) was an Italian Renaissance humanist author, artist, architect, poet, Catholic priest, priest, linguistics, linguist, philosopher, and cryptography, cryptographer; he epitomised the nature of those identified now as polymaths. He is considered the founder of European cryptography, a claim he shares with Johannes Trithemius. He is often considered primarily an architect. However, according to James Beck, "to single out one of Leon Battista's 'fields' over others as somehow functionally independent and self-sufficient is of no help at all to any effort to characterize Alberti's extensive explorations in the fine arts". Although Alberti is known mostly as an artist, he was also a mathematician and made significant contributions to that field. Among the most famous buildings he designed are the churches of San Sebastiano (1460) and Sant'Andrea (1472), both in Mantua. Alberti's life was told in Giorgio Vasari's ''Lives of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plaintext
In cryptography, plaintext usually means unencrypted information pending input into cryptographic algorithms, usually encryption algorithms. This usually refers to data that is transmitted or stored unencrypted. Overview With the advent of computing, the term ''plaintext'' expanded beyond human-readable documents to mean any data, including binary files, in a form that can be viewed or used without requiring a key or other decryption device. Information—a message, document, file, etc.—if to be communicated or stored in an unencrypted form is referred to as plaintext. Plaintext is used as input to an encryption algorithm; the output is usually termed ciphertext, particularly when the algorithm is a cipher. Codetext is less often used, and almost always only when the algorithm involved is actually a code. Some systems use multiple layers of encryption, with the output of one encryption algorithm becoming "plaintext" input for the next. Secure handling Insecure handling of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Connecticut State University
Western Connecticut State University (WCSU and WestConn) is a public university in Danbury, Connecticut. It was founded in 1903 as a teacher's college and is part of the Connecticut State University System. WCSU consists of four schools: the Ancell School of Business, the Macricostas School of Arts and Sciences, the School of Professional Studies, and the School of Visual and Performing Arts. The university offers 38 Bachelor's and one associate degree programs, 15 Master's degree programs, and two doctoral programs. WCSU is accredited by the New England Commission of Higher Education (NECHE). WCSU is home to the Jane Goodall Center for Excellence in Environmental Studies, which is the result of a partnership between WCSU and the Jane Goodall Institute (a private non-profit organization that promotes research, education and wildlife conservation). The university's Westside campus houses the Ives Concert Park, one of the premier performance venues in the area. Western Connecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
