Implementation of N-Cryptographic Multilevel Cryptography Using RSA and Substitution Cryptosystem

Abstract

The purpose of cryptography is to ensure information is made in such a way that an unintended individual will not have access to it or does not understand what it means when intercepted on a communication network. Some people try to defeat this purpose by using an extra ordinary means to harm the algorithmic construct of the system. The effort required for this purpose depends on the complexity of the algorithm and the number of cryptographic-ciphers used. Given that effort required to cryptanalyze ciphertext when one-algorithmic transformation was made is x-effort, then the effort required when n-algorithmic transformation was done is nx-effort. This paper implements multilevel encryption algorithm using two cryptosystem; RSA and Substitution cryptosystem with one transformation per each. It presents an algorithmic paradigm which can be implemented using any programming language. It simplifies the stages used for both encryption and decryption, presenting each stage in a sequential order