ABSTRACT
The term cryptography is a combination of two Greek words “Kruptos” and “Graphio”. Formally, cryptography is the study of secure designs required for the protection of sensitive communication. Cryptography deals with the means and methods of data conversation in a secure form so that the data cannot be used by unauthorized person, authenticity of the data can be established, modification on the data can be avoided and the data cannot be repudiated by the generator. In 1949, Claude Shannon in one of his fundamental papers Communication Theory of Secrecy Systems explained two properties, confusion and diffusion, that a “good” cryptosystem should satisfy in order to hinder statistical analysis. Cryptanalysis deals with the study, observations, and analysis of cryptosystem in order to attack on it. If the attacker can determine the secret key, then the cryptosystem is totally broken and there is no security at all.
