Key-Systems 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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World Wide Web (WWW) Probably the most significant Internet service, the World Wide Web is not the essence of the Internet, but a subset of it. It is constituted by documents that are linked together in a way you can switch from one document to another by simply clicking on the link connecting these documents. This is made possible by the Hypertext Mark-up Language (HTML), the authoring language used in creating World Wide Web-based documents. These so-called hypertexts can combine text documents, graphics, videos, sounds, and Especially on the World Wide Web, documents are often retrieved by entering keywords into so-called search engines, sets of programs that fetch documents from as many Among other things that is the reason why the World Wide Web is not simply a very huge database, as is sometimes said, because it lacks consistency. There is virtually almost infinite storage capacity on the Internet, that is true, a capacity, which might become an almost everlasting too, a prospect, which is sometimes According to the Internet domain survey of the |
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