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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Founded in 1929 Disney primarily engages in child and adult entertainment. Starting with the production of animated motion-picture cartoons in the late 1940s Disney began to make also nature documentaries and live-action motion pictures, as well as short cartoons and live-action programs for television. In 1955 the company opened Disneyland, which was their first amusement park. Further openings of amusement parks in the U.S. and Europe followed. In 1996 Disney acquired Capital Cities/ABC Inc., which owned the ABC television network.
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"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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b. July 13, 1527, London, England
d. December 1608, Mortlake, Surrey
English alchemist, astrologer, and mathematician who contributed greatly to the revival of interest in mathematics in England. After lecturing and studying on the European continent between 1547 and 1550, Dee returned to England in 1551 and was granted a pension by the government. He became astrologer to the queen, Mary Tudor, and shortly thereafter was imprisoned for being a magician but was released in 1555. Dee later toured Poland and Bohemia (1583-89), giving exhibitions of magic at the courts of various princes. He became warden of Manchester College in 1595.