Date Added: Apr 2012
Cryptography is an art of illusion in which the sender encodes the message using a key and sends it over the communication channel. The receiver on the other side of the channel decodes the message back and using the key tries to obtain back the original message. If the key during the communication is same on both sides then it is called as symmetric key cryptography and if is called as asymmetric key cryptography. There has been different encoding techniques used for the pain text in both block & stream cipher mode some of them are ECB & CBC for block cipher & OFB & CBC for block cipher.