A Modified Circular Version of Playfair Cipher

Abstract

In present era, data is the most valuable assets for everyone. We all share data to each other via any mode of communication. For secure communication data can be encrypted during its transmission. There are many techniques available to encrypt data in which Playfair Cipher is best known for its multiple letter encryptions. It is highly tedious for opponent to decipher the ciphertext encrypted using Playfair. The goal of this research paper is to provide security for the alphanumeric data during its transmission.

In this paper we outline the pros and cons of classical Playfair cipher. Encryption process of classical Playfair cipher uses a matrix in which letters are arranged in 5 rows and 5 columns. Arrangement of letters is based on a keyword (non repeating letters). This encryption process is only for alphabets and numeric data cannot be encrypted. So, by using alphanumeric keyword we have proposed an enhancement to the existing encryption process which is constructed in new arrangement i.e. tracks and sectors.