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Steganographic
Steganography ( ) is the practice of representing information within another message or physical object, in such a manner that the presence of the information is not evident to human inspection. In computing/electronic contexts, a computer file, message, image, or video is concealed within another file, message, image, or video. The word ''steganography'' comes from Greek ''steganographia'', which combines the words ''steganós'' (), meaning "covered or concealed", and ''-graphia'' () meaning "writing". The first recorded use of the term was in 1499 by Johannes Trithemius in his '' Steganographia'', a treatise on cryptography and steganography, disguised as a book on magic. Generally, the hidden messages appear to be (or to be part of) something else: images, articles, shopping lists, or some other cover text. For example, the hidden message may be in invisible ink between the visible lines of a private letter. Some implementations of steganography that lack a shared secret are f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steganography
Steganography ( ) is the practice of representing information within another message or physical object, in such a manner that the presence of the information is not evident to human inspection. In computing/electronic contexts, a computer file, message, image, or video is concealed within another file, message, image, or video. The word ''steganography'' comes from Greek ''steganographia'', which combines the words ''steganós'' (), meaning "covered or concealed", and ''-graphia'' () meaning "writing". The first recorded use of the term was in 1499 by Johannes Trithemius in his '' Steganographia'', a treatise on cryptography and steganography, disguised as a book on magic. Generally, the hidden messages appear to be (or to be part of) something else: images, articles, shopping lists, or some other cover text. For example, the hidden message may be in invisible ink between the visible lines of a private letter. Some implementations of steganography that lack a shared secret are f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steganography In The Hand Of John Dee
Steganography ( ) is the practice of representing information within another message or physical object, in such a manner that the presence of the information is not evident to human inspection. In computing/electronic contexts, a computer file, message, image, or video is concealed within another file, message, image, or video. The word ''steganography'' comes from Greek ''steganographia'', which combines the words ''steganós'' (), meaning "covered or concealed", and ''-graphia'' () meaning "writing". The first recorded use of the term was in 1499 by Johannes Trithemius in his '' Steganographia'', a treatise on cryptography and steganography, disguised as a book on magic. Generally, the hidden messages appear to be (or to be part of) something else: images, articles, shopping lists, or some other cover text. For example, the hidden message may be in invisible ink between the visible lines of a private letter. Some implementations of steganography that lack a shared secret are f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microdot Camera Markiv
A microdot is text or an image substantially reduced in size to prevent detection by unintended recipients. Microdots are normally circular and around in diameter but can be made into different shapes and sizes and made from various materials such as polyester or metal. The name comes from the fact that the microdots have often been about the size and shape of a typographical dot, such as a period or the tittle of a lowercase ''i'' or ''j''. Microdots are, fundamentally, a steganographic approach to message protection. History In 1870 during the Franco-Prussian War, Paris was under siege and messages were sent by carrier pigeon. Parisian photographer René Dagron used microfilm to permit each pigeon to carry a high volume of messages, as pigeons can carry little weight. Improvement in technology since then has made even more miniaturization possible. At the International Congress of Photography in Paris in 1925 Emanuel Goldberg presented a method of producing extreme reducti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microdot
A microdot is text or an image substantially reduced in size to prevent detection by unintended recipients. Microdots are normally circular and around in diameter but can be made into different shapes and sizes and made from various materials such as polyester or metal. The name comes from the fact that the microdots have often been about the size and shape of a typographical dot, such as a period or the tittle of a lowercase ''i'' or ''j''. Microdots are, fundamentally, a steganographic approach to message protection. History In 1870 during the Franco-Prussian War, Paris was under siege and messages were sent by carrier pigeon. Parisian photographer René Dagron used microfilm to permit each pigeon to carry a high volume of messages, as pigeons can carry little weight. Improvement in technology since then has made even more miniaturization possible. At the International Congress of Photography in Paris in 1925 Emanuel Goldberg presented a method of producing extreme reducti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steganographia
''Steganographia'' is a book on steganography, written in c. 1499 by the German Benedictine abbot and polymath Johannes Trithemius. General Trithemius' most famous work, ''Steganographia'' (written c. 1499; published Frankfurt, 1606), was placed on the ''Index Librorum Prohibitorum'' in 1609 and removed in 1900. This book is in three volumes, and appears to be about magic—specifically, about using spirits to communicate over long distances. However, since the publication of a decryption key to the first two volumes in 1606, they have been known to be actually concerned with cryptography and steganography. Until recently, the third volume was widely still believed to be solely about magic, but the "magical" formulae have now been shown to be covertexts for yet more material on cryptography. Reception Mentions within the third book of the magical work by such figures as Agrippa and John Dee still lend credence to the idea of a mystic-magical foundation concerning the third ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerckhoffs's Principle
Kerckhoffs's principle (also called Kerckhoffs's desideratum, assumption, axiom, doctrine or law) of cryptography was stated by Dutch-born cryptographer Auguste Kerckhoffs in the 19th century. The principle holds that a cryptosystem should be secure, even if everything about the system, except the key, is public knowledge. This concept is widely embraced by cryptographers, in contrast to security through obscurity, which is not. Kerckhoffs's principle was phrased by American mathematician Claude Shannon as "the enemy knows the system", i.e., "one ought to design systems under the assumption that the enemy will immediately gain full familiarity with them". In that form, it is called Shannon's maxim. Another formulation by American researcher and professor Steven M. Bellovin is: In other words — design your system assuming that your opponents know it in detail. (A former official at NSA's National Computer Security Center told me that the standard assumption there was that ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannes Trithemius
Johannes Trithemius (; 1 February 1462 – 13 December 1516), born Johann Heidenberg, was a German Benedictine abbot and a polymath who was active in the German Renaissance as a lexicographer, chronicler, cryptographer, and occultist. He is considered the founder of modern cryptography (a claim shared with Leon Battista Alberti) and steganography, as well as the founder of bibliography and literary studies as branches of knowledge. He had considerable influence on the development of early modern and modern occultism. His students included Heinrich Cornelius Agrippa and Paracelsus. Early life The byname ''Trithemius'' refers to his native town of Trittenheim on the Moselle River, at the time part of the Electorate of Trier. When Johannes was still an infant his father, Johann von Heidenburg, died. His stepfather, whom his mother Elisabeth married seven years later, was hostile to education and thus Johannes could only learn in secret and with many difficulties. He learned Greek, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aristagoras
Aristagoras ( grc-gre, Ἀρισταγόρας ὁ Μιλήσιος), d. 497/496 BC, was the leader of the Ionian city of Miletus in the late 6th century BC and early 5th century BC and a key player during the early years of the Ionian Revolt against the Persian Achaemenid Empire. He was the son-in-law of Histiaeus, and inherited the tyranny of Miletus from him. The Greeks had won the coast of Asia Minor from the preceding Hittite Empire during the Bronze Age, and thanks to their victory at Troy had kept it during the fall of the empire and retirement of the Hittites to Syria. They shared the coast with the Phrygians (proto-Armenians) coming in from the Balkans, but neither were prepared for the mass emigration of Iranians from the plains of Asia. Ionia appealed to the mainland Greeks for assistance and not receiving it were forced to capitulate, becoming subjects of the new Achaemenid Empire. As long as they paid their taxes and were no threat to the rule of the Persians, the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Espionage
Espionage, spying, or intelligence gathering is the act of obtaining secret or confidential information (intelligence) from non-disclosed sources or divulging of the same without the permission of the holder of the information for a tangible benefit. A person who commits espionage is called an ''espionage agent'' or ''spy''. Any individual or spy ring (a cooperating group of spies), in the service of a government, company, criminal organization, or independent operation, can commit espionage. The practice is clandestine, as it is by definition unwelcome. In some circumstances, it may be a legal tool of law enforcement and in others, it may be illegal and punishable by law. Espionage is often part of an institutional effort by a government or commercial concern. However, the term tends to be associated with state spying on potential or actual enemies for military purposes. Spying involving corporations is known as industrial espionage. One of the most effective ways to gath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Language
Greek ( el, label=Modern Greek, Ελληνικά, Elliniká, ; grc, Ἑλληνική, Hellēnikḗ) is an independent branch of the Indo-European family of languages, native to Greece, Cyprus, southern Italy (Calabria and Salento), southern Albania, and other regions of the Balkans, the Black Sea coast, Asia Minor, and the Eastern Mediterranean. It has the longest documented history of any Indo-European language, spanning at least 3,400 years of written records. Its writing system is the Greek alphabet, which has been used for approximately 2,800 years; previously, Greek was recorded in writing systems such as Linear B and the Cypriot syllabary. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic, and many other writing systems. The Greek language holds a very important place in the history of the Western world. Beginning with the epics of Homer, ancient Greek literature includes many works of lasting impo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postage Stamp
A postage stamp is a small piece of paper issued by a post office, postal administration, or other authorized vendors to customers who pay postage (the cost involved in moving, insuring, or registering mail), who then affix the stamp to the face or address-side of any item of mail—an envelope or other postal cover (e.g., packet, box, mailing cylinder)—that they wish to send. The item is then processed by the postal system, where a postmark or cancellation mark—in modern usage indicating date and point of origin of mailing—is applied to the stamp and its left and right sides to prevent its reuse. The item is then delivered to its addressee. Always featuring the name of the issuing nation (with the exception of the United Kingdom), a denomination of its value, and often an illustration of persons, events, institutions, or natural realities that symbolize the nation's traditions and values, every stamp is printed on a piece of usually rectangular, but sometimes triangular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yarn
Yarn is a long continuous length of interlocked fibres, used in sewing, crocheting, knitting, weaving, embroidery, ropemaking, and the production of textiles. Thread is a type of yarn intended for sewing by hand or machine. Modern manufactured sewing threads may be finished with wax or other lubricants to withstand the stresses involved in sewing. Embroidery threads are yarns specifically designed for needlework. Yarn can be made of a number of natural or synthetic materials, and comes in a variety of colors and thicknesses (referred to as "weights"). Although yarn may be dyed different colours, most yarns are solid coloured with a uniform hue. Etymology The word yarn comes from Middle English, from the Old English ''gearn'', akin to Old High German ''garn'', "yarn," Dutch "garen," Italian ''chordē'', "string," and Sanskrit ''hira'', "band." History The human production of yarn is known to have existed since the Stone Age and earlier prehistory, with ancient fiber mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
