Cryptography
"Cryptography, a word with Greek origin means Secret writing . However, we use the term to refer to the science and art of transforming messages to make them secure and immiane to attacks." Following figure shows the components involved in cryptography. Plain Text and Cipher Text The original message, before being transformed is called plain text. After the message is transformed, it is called cipher text. An encryption algorithm transform the plain text into cipher text; a description algorithm transformed the cipher text into plain text. The sender uses an encryption algorithm and the receiver uses a decryption algorithm. Ciphers We refer to encryption and decryption algorithm as ciphers. The term cipher is also used to refer to different categories of algorithm in cryptography. This is not o say that every sender-receiver pair needs their very own unique cipher for a secure communication on the contrary, one cipher can serve millions ...