A Novel Method for Image Encryption

Abstract

In general, playfair cipher support 5 × 5 matrix is used to generate a key matrix for encryption, which supports only 25 uppercase alphabets. To succeed in dealing with this drawback, various extended playfair cipher techniques are used. Here, a new cryptographic method of image encryption is proposed, which contains two stages to make it secure. In the first stage, we, first, performed the rotation operation, and then, we apply diffusion operation (XOR) on two consecutive pixels. Then, the extended playfair cipher (EPC) technique along with secret key is used. Here in EPC, we use 16 × 16 key matrixes which give us better result as compare to other playfair cipher technique. The proposed encryption technique is implemented on images for evaluation of security aspects and performance analysis on the basis of key size analysis, key sensitivity analysis and statistical analysis.