Info. Sec. (05): Cryptography Encryption and Decryption by Arfan Shahzad

Cryptography encryption and decryption is all about securing information system and data. Cryptography comes from the Greek words kryptos, meaning “hidden,” and graphein, meaning “to write,” and involves making and using codes to secure messages. Cryptanalysis involves cracking or breaking encrypted messages back into their unencrypted origins. Cryptography uses mathematical algorithms that are usually known to all. Encryption (Encipher): The process of converting an original message (plaintext) into a form that cannot be used by unauthorized individuals (ciphertext). Also referred to as enciphering. Encryption renders the data contents to unreadable and inaccessible form, unless one have the decryption key. Decryption (Decipher): The process of converting an encoded or enciphered message (ciphertext) back to its original readable form (plaintext). Also referred to as deciphering. Decryption requires two elements: the correct password and the corresponding decryption algorithm.