Play fair algorithm

Playfair cipher is an interesting data encryption technique with a medium level of complexity, and therefore, issuitable for security of wireless and mobile systems. Different sizes of the matrices used for key have been previously studied by researchers, but no study has been done so far that provides a comparative analysis of different matrix sizes of a key. This paper is motivated by this observation, and provides a comparison of three different matrix sizes used for the key. These matrices are 9 x9, 10 x 10, and 11 x 11.Different experiments were performed which indicate that for the data used herein, the size of the plain-text does not have a significant effect on the encryption of the output. However, the size of the key does have a notable effect and the encryption level increases with big keys of bigger sizes