MIE-SPD: A New and Highly Efficient Chaos-Based Multiple Image Encryption Technique With Synchronous Permutation Diffusion

Due to the advancement of computing technologies and the Internet of Things, there has been a notable rise in image data in different sectors. Having safety mechanisms in place is crucial to protect image data from unauthorised access. This article introduces a new and effective technique for securing multiple images concurrently. The suggested encryption method varies from other multiple image encoding approaches because of its unique synchronous permutation diffusion (SPD) functioning and fast circular shifting operation based on diffusion and permutation. SPD involves evaluating diffusion and permutation processes at the same time. When encrypting, the colour image components are merged to build a single big image. After that, the big picture is segregated into distinct cellblocks that do not overlap. Furthermore, every single block undergoes the SPD process. The encryption method is fast and efficient as it combines circular shift and SPD techniques. The method is also more efficient due to the two types of permutation operations: block-selection and circular shift. Moreover, the method is effective in both software and hardware as it utilises a single fixed type 1D chaotic map for both diffusion and permutation stages. Using the SHA-256 hash method, the input image hashes are utilised to create algorithmic key parameters, providing resistance to chosen-ciphertext and plaintext attacks. Based on the results of the security study and simulation, the proposed method is quick, highly effective in encryption, and enhances the security of cipher images.