Holographic encryption algorithm based on bit-plane decomposition and hyperchaotic Lorenz system

In recent years, many encryption algorithms based on chaotic systems have developed rapidly, and most of them only have simple confusion-diffusion structures, which only work on plaintext images. However, these algorithms will result in low encryption and small key space. This paper proposes a holographic encryption algorithm based on hyperchaotic Lorenz systems and bit-plane decomposition. Firstly, the plaintext image is converted into a phase-only hologram (also called kinoform) through an improved Gerchberg-Saxton(GS) algorithm. Secondly, perform bit-plane decomposition on the hologram, and perform Arnold scrambling on some of the decomposed sub-images; Finally, the sub-images are synthesized by bit-plane theory and XOR diffusion is taken to obtain the final encrypted image. The hyperchaotic Lorenz system generates the chaotic sequences acting on the scrambling and diffusion, and its key stream is related to the plaintext image through the SHA-256 hash function. Simulation results and performance analysis indicate that the encryption algorithm proposed in this paper has higher security performance and can resist different attacks efficiently.