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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As stated, telecommunication is seen as an unreliable media for transporting secret messages. Therefore today, cryptography is needed more than ever before, especially for e-commerce.
Key cryptosystems try to provide more privacy.
symmetric-key cryptosystems:
The same key is used for both encryption and decryption. In this case the encipherer and the recipient of the message/text have to agree on a common key before the enciphering-process can start. And most of all they should trust each other. And exactly this is the main problem of this system: how to exchange the key without offering an opportunity for stealing it?
In former times messengers or pigeons were doing the exchange of those keys.
Symmetric-key systems make sense in small entities. If a lot of people are spread over a wide area and belong to the same network, distributing the keys starts getting complicated.
Today, those cryptosystems get controlled by other keys, based on highly complex mathematical algorithms.
some symmetric-key systems are:
- DES (Data Encryption Standard), the standard for credit cards
- Triple-DES, which is a variation of DES, encrypting the plaintext three times.
- IDEA (International Data Encryption Standard)
- blowfish encryption algorithm, which is said to be faster than DES and IDEA
Security and confidence are the key-words for a popular key-system: As DES and its successors have been used for so many years and by many people without having been broken, they are considered safe - safer than others, not used that frequently, no matter whether they are actually safer or not.
For further information see:
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A server is program, not a computer, as it sometimes said, dedicated to store files, manage printers and network traffic, or process database queries.
Web sites, the nodes of the
This book gives a fascinating glimpse of the many documented attempts throughout history to develop effective means for long distance communications. Large-scale communication networks are not a twentieth-century phenomenon. The oldest attempts date back to millennia before Christ and include ingenious uses of homing pigeons, mirrors, flags, torches, and beacons. The first true nationwide data networks, however, were being built almost two hundred years ago. At the turn of the 18th century, well before the electromagnetic telegraph was invented, many countries in Europe already had fully operational data communications systems with altogether close to one thousand network stations. The book shows how the so-called information revolution started in 1794, with the design and construction of the first true telegraph network in France, Chappe's fixed optical network.
http://www.it.kth.se/docs/early_net/