Timeline Cryptography - Introduction

Besides oral conversations and written language many other ways of information-transport are known: like the bush telegraph, drums, smoke signals etc. Those methods are not cryptography, still they need en- and decoding, which means that the history of language, the history of communication and the history of cryptography are closely connected to each other
The timeline gives an insight into the endless fight between enciphering and deciphering. The reasons for them can be found in public and private issues at the same time, though mostly connected to military maneuvers and/or political tasks.

One of the most important researchers on Cryptography through the centuries is David Kahn; many parts of the following timeline are originating from his work.

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some essential definitions

some essential definitions in the field of cryptography are:
- cryptoanalysis
- cryptology
- ciphers

"Few false ideas have more firmly gripped the minds of so many intelligent men than the one that, if they just tried, they could invent a cipher that no one could break." (David Kahn)

codes
plaintext
ciphertext
to encipher/encode
to decipher/decode

The variants of encryption systems are endless.
For deciphering there exists always the same game of trial and error (first guessing the encryption method, then the code). A help to do so is pruning. Once, after a more or less long or short period a code/cipher breaks. Monoalphabetic ciphers can be broken easily and of course are no longer used today but for games.

for further information on codes and ciphers etc. see:
http://www.optonline.com/comptons/ceo/01004A.html
http://www.ridex.co.uk/cryptology/#_Toc439908851

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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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DES

The U.S. Data Encryption Standard (= DES) is the most widely used encryption algorithm, especially used for protection of financial transactions. It was developed by IBM in 1971. It is a symmetric-key cryptosystem. The DES algorithm uses a 56-bit encryption key, meaning that there are 72,057,594,037,927,936 possible keys.

for more information see:
http://www.britannica.com/bcom/eb/article/3/0,5716,117763+5,00.html
http://www.cryptography.com/des/

http://www.britannica.com/bcom/eb/article/3/0...
http://www.cryptography.com/des/
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