Securing images using chaos and multidimensional Playfair cipher

Image is utilized in diverse fields due to its vividness, intuitiveness, and copiousness. Existing methods for image encryption have limitations to support for 24-bit pixel images, greater cipher image size, low resistance against differential attacks, the high correlation between cipher images obtained by using a 1-bit modification of the plain image, restriction on the size of the secret image and overhead of sharing secret key among participants for every secret image. The proposed encryption method uses hyper-chaotic Chen system based triple permutation, XORing, and multidimensional Playfair encryption that overcome the limitations in the existing methods. The statistical analysis is performed in respect of the parameters: histogram analysis, correlation coefficient, randomness tests, information entropy, encryption quality, diffusion characteristics, Mean Absolute Error, key and search space analysis, and computational complexity. The results of the analysis manifest that the proposed method has got potency to be an efficient image encryption method.