Alphanumeric Encryption: The 6x6 Structure of Playfair Cipher

The information exchange is a significant task in any telecommunication system with set of protocols. The information sharing is one aspect but to secure the afore-mentioned exchange is another aspect too, which remains the point of attention for security analysts from decades. The security analysts are more keen to design and develop algorithms not only to preserve the confidentiality and integrity of the information which is part of any exchange but also concern about less computationally intensive techniques. The Playfair was known to be one of the most distinguished, simple to implement ciphers in the history of cryptography, which provides a straightforward yet effective way to encrypt pair of letters. However, this structure had many flaws which make it inefficient to use in modern era of the communication systems. In this paper a more efficient version of Playfair is proposed having few new rules incorporated to address the existing limitation of traditional version. To increase the complexity of proposed scheme which shield against attacks is one objective, and to make it use with ease is the another aim of this study. The proposed algorithm can be used in such an applications where the uses of high computationally intensive algorithms prohibited.