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Null Cipher
A null cipher, also known as concealment cipher, is an ancient form of encryption where the plaintext is mixed with a large amount of non-cipher material. Today it is regarded as a simple form of steganography, which can be used to hide ciphertext. This is one of three categories of cipher used in classical cryptography along with substitution ciphers and transposition ciphers. Classical cryptography In classical cryptography, a ''null'' is an extra character intended to confuse the cryptanalyst. In the most common form of a null cipher, the plaintext is included within the ciphertext and one needs to discard certain characters in order to decrypt the message (such as first letter, last letter, third letter of every second word, etc.) Most characters in such a cryptogram are nulls, only some are significant, and some others can be used as pointers to the significant ones. Here is an example null cipher message, sent by a German during World War I: Taking the first letter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encryption
In Cryptography law, cryptography, encryption (more specifically, Code, encoding) is the process of transforming information in a way that, ideally, only authorized parties can decode. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Despite its goal, encryption does not itself prevent interference but denies the intelligible content to a would-be interceptor. For technical reasons, an encryption scheme usually uses a pseudo-random encryption Key (cryptography), key generated by an algorithm. It is possible to decrypt the message without possessing the key but, for a well-designed encryption scheme, considerable computational resources and skills are required. An authorized recipient can easily decrypt the message with the key provided by the originator to recipients but not to unauthorized users. Historically, various forms of encryption have been used to aid in cryptography. Early encryption ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invisible Ink
Invisible ink, also known as security ink or sympathetic ink, is a substance used for writing, which is invisible either on application or soon thereafter, and can later be made visible by some means, such as heat or ultraviolet light. Invisible ink is one form of steganography. History One of the earliest writers to mention an invisible ink is Aeneas Tacticus, in the 4th century BC. He mentions it in discussing how to survive under siege but does not indicate the type of ink to be used. This was part of his list of the 20 different methods of secret communications in a book called ''On the Defense of Fortifications''. One of the techniques that involved steganography involved puncturing a tiny hole above or below letters in a document to spell out a secret message. This did not include an invisible ink but the Germans improved on the method during World War I and World War II. They used invisible ink and microdots instead of pinpricks. Philo of Byzantium may be the first write ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical Cipher
In cryptography, a classical cipher is a type of cipher that was used historically but for the most part, has fallen into disuse. In contrast to modern cryptographic algorithms, most classical ciphers can be practically computed and solved by hand. However, they are also usually very simple to break with modern technology. The term includes the simple systems used since Greek and Roman times, the elaborate Renaissance ciphers, World War II cryptography such as the Enigma machine and beyond. In contrast, modern strong cryptography relies on new algorithms and computers developed since the 1970s. Types of classical ciphers Classical ciphers are often divided into ''transposition ciphers'' and ''substitution ciphers'', but there are also '' concealment ciphers''. Substitution ciphers In a substitution cipher, letters, or groups of letters, are systematically replaced throughout the message for other letters, groups of letters, or symbols. A well-known example of a substitution c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Code (cryptography)
In cryptology, a code is a method used to encrypt a message that operates at the level of meaning; that is, words or phrases are converted into something else. A code might transform "change" into "CVGDK" or "cocktail lounge". The U.S. National Security Agency defined a code as "A substitution cryptosystem in which the plaintext elements are primarily words, phrases, or sentences, and the code equivalents (called "code groups") typically consist of letters or digits (or both) in otherwise meaningless combinations of identical length."A History of U.S. Communications Security; the David G. Boak Lectures , National Security Agency (NSA), Volumes I, 1973, Volumes II 1981, partially released 2008, additional portions declassified October 14, 2015 A ' ... [...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] |
Null (SQL)
In SQL, null or NULL is a special marker used to indicate that a data value does not exist in the database. Introduced by the creator of the Relational model, relational database model, E. F. Codd, SQL null serves to fulfill the requirement that all ''true relational database management systems (Relational database#RDBMS, RDBMS)'' support a representation of "missing information and inapplicable information". Codd also introduced the use of the lowercase Greek omega (ω) symbol to represent null in database theory. In SQL, NULL is a List of SQL reserved words, reserved word used to identify this marker. A null should not be confused with a value of 0. A null indicates a lack of a value, which is not the same as a zero value. For example, consider the question "How many books does Adam own?" The answer may be "zero" (we ''know'' that he owns ''none'') or "null" (we ''do not know'' how many he owns). In a database table, the Column (database), column reporting this answer would ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrostic
An acrostic is a poem or other word composition in which the ''first'' letter (or syllable, or word) of each new line (or paragraph, or other recurring feature in the text) spells out a word, message or the alphabet. The term comes from the French from post-classical Latin , from Koine Greek , from Ancient Greek "highest, topmost" and "verse". As a form of constrained writing, an acrostic can be used as a mnemonic device to aid memory retrieval. When the ''last'' letter of each new line (or other recurring feature) forms a word it is called a telestich (or telestic); the combination of an acrostic and a telestich in the same composition is called a double acrostic (e.g. the first-century Latin Sator Square). Acrostics are common in medieval literature, where they usually serve to highlight the name of the poet or his patron, or to make a prayer to a saint. They are most frequent in verse works but can also appear in prose. The Middle High German poet Rudolf von Ems for ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substitution Ciphers
In cryptography, a substitution cipher is a method of encrypting in which units of plaintext are replaced with the ciphertext, in a defined manner, with the help of a key; the "units" may be single letters (the most common), pairs of letters, triplets of letters, mixtures of the above, and so forth. The receiver deciphers the text by performing the inverse substitution process to extract the original message. Substitution ciphers can be compared with transposition ciphers. In a transposition cipher, the units of the plaintext are rearranged in a different and usually quite complex order, but the units themselves are left unchanged. By contrast, in a substitution cipher, the units of the plaintext are retained in the same sequence in the ciphertext, but the units themselves are altered. There are a number of different types of substitution cipher. If the cipher operates on single letters, it is termed a simple substitution cipher; a cipher that operates on larger groups of letters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transposition Cipher
In cryptography, a transposition cipher (also known as a permutation cipher) is a method of encryption which scrambles the positions of characters (''transposition'') without changing the characters themselves. Transposition ciphers reorder units of plaintext (typically characters or groups of characters) according to a regular system to produce a ciphertext which is a permutation of the plaintext. They differ from Substitution cipher, substitution ciphers, which do not change the position of units of plaintext but instead change the units themselves. Despite the difference between transposition and substitution operations, they are often combined, as in historical ciphers like the ADFGVX cipher or complex high-quality encryption methods like the modern Advanced Encryption Standard (AES). General principle Plaintexts can be rearranged into a ciphertext using a Key (cryptography), key, scrambling the order of characters like the shuffled pieces of a jigsaw puzzle. The resulting m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Insider
''Business Insider'' (stylized in all caps: BUSINESS INSIDER; known from 2021 to 2023 as INSIDER) is a New York City–based multinational financial and business news website founded in 2007. Since 2015, a majority stake in ''Business Insider''s parent company Insider Inc. has been owned by the international publishing house Axel Springer. It operates several international editions, including one in the United Kingdom. ''Insider'' publishes original reporting and aggregates material from other outlets. it maintained a liberal policy on the use of anonymous sources. It has also published native advertising and granted sponsors editorial control of its content. The outlet has been nominated for several awards, but has also been criticized for using factually incorrect clickbait headlines to attract viewership. In 2015, Axel Springer SE acquired 88 percent of the stake in Insider Inc. for $343 million (€306 million), implying a total valuation of $442 million. From ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicholas Murray Butler
Nicholas Murray Butler (April 2, 1862 – December 7, 1947) was an American philosopher, diplomat, and educator. Butler was president of Columbia University, president of the Carnegie Endowment for International Peace, a recipient of the Nobel Peace Prize, and the late James S. Sherman's replacement as William Howard Taft’s running mate in the 1912 United States presidential election. ''The New York Times'' printed his Christmas greeting to the nation for many years during the 1920s and 1930s. Early life and education Butler, great-grandson of Morgan John Rhys, was born in Elizabeth, New Jersey, to Mary Butler and manufacturing worker Henry Butler. He enrolled in Columbia College (later Columbia University) and joined the Peithologian Society. He earned his bachelor of arts degree in 1882, his master's degree in 1883 and his doctorate in 1884. Butler's academic and other achievements led Theodore Roosevelt to call him "Nicholas Miraculous". In 1885, Butler studied in Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poetry Magazine
''Poetry'' (founded as ''Poetry: A Magazine of Verse'') has been published in Chicago since 1912. It is one of the leading monthly poetry journals in the English-speaking world. Founded by poet and arts columnist Harriet Monroe, who built it into an influential publication, it is now published by the Poetry Foundation. In 2007 the magazine had a circulation of 30,000, and printed 300 poems per year out of approximately 100,000 submissions.Goodyear, Dana"The Moneyed Muse: What can two hundred million dollars do for poetry?" article, ''The New Yorker'', double issue, February 19 and February 26, 2007 It is sometimes referred to as ''Poetry—Chicago''. ''Poetry'' has been financed since 2003 with a $200 million bequest from philanthropist and Lilly heiress, Ruth Lilly. History The magazine was founded in 1912 by Harriet Monroe, an author who was then working as an art critic for the ''Chicago Tribune''. She wrote at that time: "The Open Door will be the policy of this magazin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
