Differential cryptanalysis of image cipher using block-based scrambling and image filtering

Abstract Recently, an image encryption algorithm using block-based scrambling and image filtering was proposed by Hua et al. The main idea of the encryption algorithm is to utilize image filtering to permutate and diffuse plain-images. In this paper, we analyze the security problems of the encryption algorithm in detail and break the encryption using a codebook attack. A linear relation between plain-images and cipher-images is disclosed by differential cryptanalysis. Using the linear relation, we build a codebook containing ( M × N + 1 ) pairs of cipher-images and the corresponding plain-images, where M × N is the size of plain-images. The proposed codebook attack indicates that the encryption algorithm is insecure. To defend the codebook attack, an improved algorithm is proposed. Experimental results show that the improved algorithm not only inherits the merits of the original algorithm, but also improves security robustness against the proposed differential cryptanalysis.