Overview of Cryptography

Abstract

Until very recently, the term "cryptography" was almost always used to refer to "encryption," which is the act of transforming plaintext or conventional information into an unintelligible form (called cipher text). Decryption is the opposite, or the process of returning plaintext from the unintelligible cipher text. The encryption and reversing decryption operations are carried out by a pair of algorithms known as cyphers (or cyphers). The algorithm and, in each case, a "key" work together just to regulate the precise operation of a cypher. The key, which is required to decrypt the cipher text, is a secret that should ideally only be known by the communicants. It typically takes the form of a short string of characters that the user can remember. A "cryptosystem" is the ordered list of elements with a finite number of potential combinations in formal mathematics.