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Digital Signatures, Timestamps etc |
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Most computer systems are far from being secure.
A lack of security - it is said - might hinder the developments of new information technologies. Everybody knows electronic transactions involve a more or less calculated risk. Rumors about insecurity let consumers doubt whether the commodity of e-commerce is bigger or its risks. First of all the market depends on the consumer's confidence. To provide that another application for public key cryptography gets essential: the digital signature, which is used to verify the authenticity of the sender of certain data.
It is done with a special private key, and the public key is verifying the signature. This is especially important if the involved parties do not know one another. The DSA (= Digital Signature Algorithm) is a public-key system which is only able to sign digitally, not to encrypt messages. In fact digital signature is the main-tool of cryptography in the private sector.
Digital signatures need to be given for safe electronic payment. It is a way to protect the confidentiality of the sent data, which of course could be provided by other ways of cryptography as well. Other security methods in this respect are still in development, like digital money (similar to credit cards or checks) or digital cash, a system that wants to be anonymous like cash, an idea not favored by governments as it provides many opportunities for money laundry and illegal transactions.
If intellectual property needs to be protected, a digital signature, together with a digital timestamp is regarded as an efficient tool.
In this context, the difference between identification and authentication is essential. In this context smartcards and firewalls are relevant, too.
A lot of digital transactions demand for passwords. More reliable for authentication are biometric identifiers, full of individual and unrepeatable codes, signatures that can hardly be forged.
For more terms of cryptography and more information see:
 http://poseidon.csd.auth.gr/signatures
http://www.dlib.org/dlib/december97/ibm/12lotspiech.html
http://www.cryptography.com/technology/technology.html
http://www.cdt.org/crypto/glossary.shtml
http://www.oecd.org//dsti/sti/it/secur/prod/GD97-204.htm
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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  Java applets, so making multimedia content possible.
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 servers as possible and index the stored information. (For regularly updated lists of the 100 most popular words that people are entering into search engines, click here). No search engine can retrieve all information on the whole World Wide Web; every search engine covers just a small part of it.
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 consoling, but threatening too.
According to the Internet domain survey of the Internet Software Consortium the number of Internet host computers is growing rapidly. In October 1969 the first two computers were connected; this number grows to 376.000 in January 1991 and 72,398.092 in January 2000.
World Wide Web History Project, http://www.webhistory.org/home.html
 http://www.searchwords.com/
http://www.islandnet.com/deathnet/
http://www.salonmagazine.com/21st/feature/199...
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