1950: The Turing Test

Alan Turing, an English mathematician and logician, advocated the theory that eventually computers could be created that would be capable of human thought. To cut through the long philosophical debate about exactly how to define thinking he proposed the "imitation game" (1950), now known as Turing test. His test consisted of a person asking questions via keyboard to both a person and an intelligent machine within a fixed time frame. After a series of tests the computers success at "thinking" could be measured by its probability of being misidentified as the human subject. Still today Turing's papers on the subject are widely acknowledged as the foundation of research in artificial intelligence.

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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:
http://www.sbox.tu-graz.ac.at/home/j/jonny/projects/crypto/symmetr/content.htm

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Braille

Universally accepted system of writing used by and for blind persons and consisting of a code of 63 characters, each made up of one to six raised dots arranged in a six-position matrix or cell. These Braille characters are embossed in lines on paper and read by passing the fingers lightly over the manuscript. Louis Braille, who was blinded at the age of three, invented the system in 1824 while a student at the Institution Nationale des Jeunes Aveugles (National Institute for Blind Children), Paris.

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William Frederick Friedman

Friedman is considered the father of U.S.-American cryptoanalysis - he also was the one to start using this term.

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