A Modified Playfair Cipher for Encrypting Digital Images

Abstract

In this paper, a new extension of the Playfair cipher algorithm is proposed to encrypt image data more securely. The proposed method constructs a 16×16 secret key matrix to scramble image data byte by byte. In addition, the algorithm complexity is increased using masking and XOR procedure. That is, the key is used to generate a mask that is subsequently XORed with the scrambled image. Experimental results showed that using two slightly different secret keys, the resultant encrypted images are still completely different.