The devices often considered the first "computers" in our understanding were rather
In 1642
Further improvements in the field of early computing devices were made by Charles Xavier Thomas de Colmar, a Frenchmen. His arithometer could not only add and multiply, but perform the four basic arithmetic functions and was widely used up until the First World War.
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some essential definitions in the field of cryptography are:
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"Few false ideas have more firmly gripped the minds of so many intelligent men than the one that, if they just tried, they could invent a cipher that no one could break." (David Kahn)
The variants of encryption systems are endless.
For deciphering there exists always the same game of trial and error (first guessing the encryption method, then the code). A help to do so is pruning. Once, after a more or less long or short period a code/cipher breaks. Monoalphabetic ciphers can be broken easily and of course are no longer used today but for games.
for further information on codes and ciphers etc. see:
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Research in
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the word "cipher" comes from the Hebrew word "saphar", meaning "to number". Ciphers are mere substitutions. Each letter of the alphabet gets substituted; maybe by one letter or two or more.
an example:
PLAINTEXT a b c d e f g h i j k l m n o p q r s t u v w x y z
CIPHERTEXT D E F G H I J K L M N O P Q R S T U V W X Y Z A B C
The first of the great medieval universities was established at 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 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,
The Roman smoke signals network consisted of towers within 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
Aeneas Tacitus, a Greek military scientist and cryptographer, invented an optical communication system that combines water and beacon telegraphy. Torches indicated the beginnings and the ends of message transmissions while water jars were used to transmit the messages. These jars had a plugged standard-size hole drilled on the bottom side and were filled with water. As those who sent and those who received the message unplugged the jars simultaneously, the water drained out. Because the transmitted messages corresponded to water levels, the sender indicated by torch signal that the appropriate water level has been reached. It is a disadvantage that the possible messages are restricted to a given code, but as this system was mainly used for military purposes, this was offset by the advantage that it was almost impossible for outsiders to understand these messages unless they possessed the codebook.
With communication separated from transportation, the distant became near.
Tacitus' telegraph system was very fast and not excelled until
For further information see Joanne Chang & Anna Soellner, Decoding Device,
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