Modified AES-256 Algorithm with Multiple-Keys for Secure Data Transmission and Persistent Storage

Abstract

Symmetric Crypto-system usually has a single key and consumes less amount of time both for Encryption and Decryption. Asymmetric crypto-system has two keys but considerable amount of time consumed both for Encryption and Decryption. But Asymmetric crypto-systems are very difficult to crack.  So there is a need for increasing security in symmetric crypto-system by creating multiple keys both for secure transfer and secure persistent storage with less time needed for Encryption and Decryption. In this paper we modified Symmetric AES-256 algorithm to use multiple keys both for encryption and decryption. We also tested the algorithm for performance through cryptanalysis, execution and throughput analysis. We also compared the proposed algorithm for performance with the existing algorithms and it shows better improvement than the algorithms that currently exists in terms of security, Encryption and Decryption.