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Introduction "A man is crazy who writes a secrete in any other way than one which will conceal it from the vulgar." Roger Bacon (~1250 AD) The essence of human communication is not only the social behavior to give or get messages (of whatever meaning) but also how to give and get them, and to include certain people by excluding others from the process of informing. e.g. whispering is an effective way of talking to exclude the majority. What about ways of writing? Already some of the first written messages in human history obviously found special forms of hiding contents from the so-called others. When the knowledge of writing meant a privilege in a stronger sense as it is true today (in China for a long period writing was forbidden to people not working for the government), the alphabet itself was a kind of cryptography (that is why Catholic churches were painted with pictures explaining the stories of the Bible). Certainly the methods of deciphering and enciphering improved a lot during the last 4.000 years. In the meantime cryptography has become a topic without end and with less technological limits every day. On the one hand there is the field of biometrics, which is highly related to cryptography but still in its beginnings, on the other hand there emerge so-called infowars, which intend to substitute or at least accompany war and are unthinkable without cryptography. But there is much more to detect, like the different forms of de- and encoding. And very important, too, there is the history of cryptography that tells us about the basics to make it easier to understand today's issues. In the actual age of (dis-)information storing and transporting electronic information safely increases its importance. Governments, institutions, economy and individuals rely on the hope that no-one can read or falsify their messages/data as it is much more difficult to detect and proof abuses in electronic media than in elder forms of written communication. |
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Timeline 00 - 1600 AD 3rd cent. Leiden papyrus: medical information gets enciphered to stop abuses 8th cent. - Abu 'Abd al-Rahman al-Khalil ibn Ahmad ibn 'Amr ibn Tammam al Farahidi al-Zadi al Yahmadi finds the solution for a Greek cryptogram by first of all finding out the plaintext behind the encryption, a method which never got out of date. Afterwards he writes a book on cryptography. - cipher alphabets for magicians are published 1250 the English monk Roger Bacon writes cipher-descriptions. At that time the art of enciphering was a popular game in monasteries 1379 Gabrieli di Lavinde develops the nomenclature-code for Clement VII (114); a code-system made out of ciphers and codes, which kept being irreplaceable until the 19th century 1392 (probably) the English poet Geoffrey Chaucer writes the book The Equatorie of the Planetis, which contains several passages in ciphers made out of letters, digits and symbols 1412 for the first time ciphers including different substitutions for each letter are developed (in Arabic) ~1467 invention of the "Captain Midnight Decoder Badge", the first polyalphabetic cipher (disk); the inventor, Leon Battista Alberti, also called the father of Western cryptography, uses his disk for enciphering and deciphering at the same time 15th/16th century nearly every state, especially England and France, has people working on en- and deciphering for them 1518 the first printed book on cryptology is written by the German monk Johannes Trithemius. He also changes the form of polyalphabetic cipher from disks into rectangulars 1533 the idea to take a pass-phrase as the key for polyalphabetic cipher is realized by Giovan Batista Belaso 1563 Giovanni Battista Porta suggests to use synonyms and misspellings to irritate cryptoanalysts 1585 Blaise de Vigenère has the idea to use former plaintexts or ciphertexts as new keys; he invents the 1587 Mary, Queen of Scots, is beheaded for the attempt to organize the murder of Queen Elisabeth I., whose agents find out about Mary's plans with the help of decryption 1588 the first book in shorthand is published |
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Cryptography's Terms and background "All nature is merely a cipher and a secret writing." Blaise de Vigenère In the (dis-)information age getting information but at the same time excluding others from it is part of a power-game (keeping the other uneducated). The reason for it eventually has found an argument called security. Compared to the frequency of its presence in articles, the news and political speeches security seems to be one of the most popular words of the 90's. It must be a long time ago when that word was only used for and by the military and the police. Today one can find it as part of every political issue. Even development assistance and nutrition programs consider it part of its work. The so-called but also real need for information security is widespread and concerning everybody, whether someone uses information technology or not. In any case information about individuals is moving globally; mostly sensitive information like about bank records, insurance and medical data, credit card transactions, and much much more. Any kind of personal or business communication, including telephone conversations, fax messages, and of course e-mail is concerned. Not to forget further financial transactions and business information. Almost every aspect of modern life is affected. We want to communicate with everybody - but do not want anybody to know. Whereas the market already depends on the electronic flow of information and the digital tools get faster and more sophisticated all the time, the rise of privacy and security concerns have to be stated as well. With the increase of digital communication its vulnerability is increasing just as fast. And there exist two (or three) elements competing and giving the term digital security a rather drastic bitter taste: this is on the one hand the growing possibility for criminals to use modern technology not only to hide their source and work secretly but also to manipulate financial and other transfers. On the other hand there are the governments of many states telling the population that they need access to any kind of data to keep control against those criminals. And finally there are those people, living between enlightening security gaps and at the same time harming other private people's actions with their work: computer hackers. While the potential of global information is regarded as endless, it is those elements that reduce it. There is no definite solution, but at least some tools have been developed to improve the situation: cryptography, the freedom to encode those data that one does not want to be known by everybody, and give a possibility to decode them to those who shall know the data. During the last 80 years cryptography has changed from a mere political into a private, economic but still political tool: at the same time it was necessary to improve the tools, eventually based on mathematics. Hence generally cryptography is regarded as something very complicated. And in many ways this is true as the modern ways of enciphering are all about mathematics. "Crypto is not mathematics, but crypto can be highly mathematical, crypto can use mathematics, but good crypto can be done without a great reliance on complex mathematics." (W.T. Shaw) For an introduction into cryptography and the mathematical tasks see: |
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0 - 1400 A.D. 150 A The Roman smoke signals network consisted of towers within a visible range of each other and had a total length of about 4500 kilometers. It was used for military signaling. For a similar telegraph network in ancient Greece see About 750 In Japan block printing is used for the first time. 868 In China the world's first dated book, the Diamond Sutra, is printed. 1041-1048 In China moveable types made from clay are invented. 1088 The first of the great medieval universities was established in Bologna. At the beginning universities predominantly offered a kind of do-it-yourself publishing service. Books still had to be copied by hand and were so rare that a copy of a widely desired book qualified for being invited to a university. Holding a lecture equaled to reading a book aloud, like a priest read from the Bible during services. Attending a lecture equaled to copy a lecture word by word, so that you had your own copy of a book, thus enabling you to hold a lecture, too. For further details see History of the Idea of a University, |
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water-clocks The water-clocks are an early long-distance-communication-system. Every communicating party had exactly the same jar, with a same-size-hole that was closed and the same amount of water in it. In the jar was a stick with different messages written on. When one party wanted to tell something to the other it made a fire-sign. When the other answered, both of them opened the hole at the same time. And with the help of another fire-sign closed it again at the same time, too. In the end the water covered the stick until the point of the wanted message. |
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Hieroglyphs Hieroglyphs are pictures, used for writing in ancient Egypt. First of all those pictures were used for the names of kings, later more and more signs were added, until a number of 750 pictures |
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