An extended Playfair Cipher using rotation and random swap patterns

In this paper, we have proposed an encryption method which is developed by extending Playfair Cipher to make it more secure. Known as Polyalphabetic cipher, Playfair uses a key matrix containing 25 characters for encryption. This extended playfair cipher supports all 26 characters filled in two different key matrices, second matrix having extra checksum characters. As Playfair is susceptible to various attacks, so to avoid that, we included rotation operation on key matrices and swapping of rows and columns of key matrices according to randomly generated swap patterns. Cryptanalysis of new proposed extended cipher is done by performing various attacks and we conclude that this technique is more secure and can be used as a part of advanced encryption algorithms like AES, DES.