Application of modulus theory to crytographic system

In this paper, introduce the reader to some of the fundamental notions of cryptography in a number theory context. Cryptography has long been an important issue in the realm of computers, mainly due to security needed for passwords. Security is a human issue in today’s world. Cryptography is only as good as the practices of the people who use it. With the growing quantity of digital data stored, communicated by electronic data, processing system, organization like public and commercial sectors have felt the need to protect information from unwanted intrusion. These wide spread uses of electronic funds transfer has made privacy a pressing concern in most financial transaction. There for the secret communication system are needed. The complexity of cryptography effectively puts it outside the understanding of most people and so motivation for the practices of cryptographic security is not available.