10-04-2012, 11:24 AM
Cryptography
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(Crypto means hidden or secret)
Cryptography, which comes from the Greek words ‘Kryptos’ or ‘hidden’ and graphein ‘to write’, is the science of sectret communication. It is a methodology for transforming the representation or appearance of a message without changing its information content. The original message is called plaintext and the transformed message is known as cipher text.
A crypto algorithm is a procedure that takes the plaintext data and transforms it into cipher text in a reversible way.
Cryptosystems use what are called keys—public key and private key. Encrypt and decrypt.