Multi-cube encryption scheme for multi-type images based on modified Klotski game and hyperchaotic map

With the advent of the big data era, designing security protection schemes for large amounts of image information has become an urgent problem. Multi-image encryption (MIE) algorithms provide a method for batch encryption of images, but the problems of compatibility of algorithms to image types and slow encryption speed have not been solved better. To address the above issues, inspired by the traditional Chinese game Klotski, this scheme is designed as a novel MIE algorithm. First, multiple plain images fused into a multi-image cube is performed with point-to-point confusion. Next, each plane is divided into a number of small pieces by different schemes, and then the different-sized pieces are stacked to form multiple cubes. Next, the faces of the small cube are rotated and exchanged positions, and then the small cube is combined into a large cube by different schemes. Finally, a diffusion operation is performed on each pixel of the large cube to generate the cipher cube. Since the size of the image cube is variable, there is no restriction on the type and size of the plain image being encrypted. The simulation and security analysis results show that the scheme can pass all the performance tests, and some of these indicators also have advantages compared to similar schemes, and in the encryption and decryption efficiency has a more obvious improvement compared to other schemes, which proves that the scheme securely and efficiently encrypts and decrypts images.