Cryptography Playfair Cipher using Linear Feedback Shift Register

Abstract

In this paper we present a new approach for secure transmission of message by modified version of Play fair cipher combining with Random number generator methods. To develop this method of encryption technique, one of the simplest methods of random number generator methods called Linear Feedback Shift Register (LFSR) has been used. Play fair cipher method based on poly alphabetic cipher. It is relatively easy to break because it still leaves much of the structure and a few hundred of letters of cipher text are sufficient. Here we are mapping random numbers to secret key of Play fair cipher method and corresponding numbers will be transmitted to the recipient instead of alphabetical letter. This method rapidly increases security of the transmission over an unsecured channel.