Data Security and Cryptography Substitution Techniques Algorithms implementation

Abstract

Cryptography and data security have been used
to make data more secure for many years, military
communications are having a major impact on growing
cryptography field. Although the internet have been invited
in the ends 1960's, but it is not appear to public until invent
the World Wide Web (www) in 1989. The World Wide Web
allows people to e-mail each other and transfer data. This
appeared as one reason in growing use of computer. In
addition needs to make e-commerce more secure.
Cryptography understanding helps to find better ways or
protocols to make transfer data faster and more efficient.
This paper starts with a brief background about security
and cryptography. It provides central concepts of
cryptography. Also provides an account of substitution
techniques algorithms and their implementation. The
implementation will be as an application in c# language that
reads a text, encodes it by a specified algorithm and decodes
the encrypted text. In addition explaining the mathematical
functions used in the algorithms