Running Head: CRYPTOGRAPHIC ALGORITHMS
DES Secret Key Algorithms
A secret key is a piece of code or parameter that is designed to both encrypt and decrypt
messages in a symmetric encryption. It is also called symmetric cryptography. This name is
derived from its ability to encrypt and decrypt data using the same key. Therefore, both
communicating parties must have access to the key, but be the only ones that can access it for the
communication to remain anonymous. A secret key uses two main categories of algorithms;
stream ciphers and block ciphers. A block cipher is divided into two categories; a secret key
processer called a key schedule, and a data path which carries plaintext and ciphertext. The key
schedule algorithm sorts out the secret key by deriving it from the “round keys” that are found in
the data path. Each round key is used in every round.
Block ciphers are popularly used in Data Encryption Standard (DES), a system that was
designed by International Business Machines (IBM) in the 1970s. Similar to block ciphers, a
DES is made up of two segments; a key program/schedule...