Differential cryptanalysis of image cipher using block-based scrambling and image filtering
This work addresses security vulnerabilities in image encryption for applications like secure communication, though it is incremental as it builds on and improves an existing scheme.
The paper analyzes and breaks an existing image encryption algorithm using block-based scrambling and image filtering via differential cryptanalysis and a codebook attack, showing it is insecure; it then proposes an improved algorithm that maintains the original benefits while enhancing security against such attacks.
Recently, an image encryption algorithm using block-based scrambling and image filtering has been proposed by Hua et al. In this paper, we analyze the security problems of the encryption algorithm in detail and break the encryption by a codebook attack. We construct an linear relation between plain-images and cipher-images by differential cryptanalysis. With this linear relation, we build a codebook containing $(M \times N + 1)$ pairs of plain-images and cipher-images, where $M\times N$ is the size of images. The proposed codebook attack indicates that the encryption scheme is insecure. To resist the codebook attack, an improved algorithm is proposed. Experimental results show that the improved algorithm not only inherits the merits of the original scheme, but also has stronger security against the differential cryptanalysis.