An Extended Playfair Encryption Technique Based on Fibonacci Series

The rapid advancement in networking technologies leads to the sharing of information by millions of users at a much higher rate. Information sharing over unprotected network may lead to compromise of the sensitive and confidential information to unauthorized person. Cryptography is one of the several ways to guard sensitive and confidential information. Before sharing the information over the Internet, it must be encrypted to preserve its confidentiality. Encryption is a process of converting readable information into scrambled form so that no unauthorized person can make use of it. In this paper, the Playfair encryption technique is taken into consideration for encrypting the information to be shared. In its simplest form, the Playfair encryption technique generates a 5 × 5 key table by taking a key as input and encrypts the diagraphs of actual message. The key generation process is improved by modifying it with Fibonacci series. The Fibonacci series is used create a random key, which is passed to generate 5 × 5 key table. This key table is used to encrypt the actual message using rules defined by Playfair encryption algorithm. In this paper, the limitations of 5 × 5 key table are removed by using an 8 × 8 key table, which provides much higher level of security to the message being encrypted.