Dual Level Security for Key Exchange using Modified RSA Public Key Encryption in Playfair Technique

Abstract

The objective of this paper is to provide the dual level security for the key in playfair cipher using modified RSA digital signature scheme. This work has two phases, in the first phase the key is converted into the ASCII code and in the second phase, this work is using the concept of modified RSA digital signature scheme in which user authentication, data integrity and non-repudiation services are provided but as all know that in playfair technique, key exchange process is most important so there is a need to secure the key during key transfer that’s why this work is using the concept of modified RSA public key encryption technique to encrypt the key before sending it to the receiver for decryption. This work use a 10*8 matrix which contain all alphabetic in the uppercase as well as in lowercase, the numeric value from 0 to 9, list of operator and list of bracket. General Terms Key Security.