A novel hyperchaotic image encryption algorithm with simultaneous shuffling and diffusion

The performance of an image encryption algorithm based on chaos is largely determined by the nonlinear characteristics of the underlying chaotic system. This paper proposes a mixed one- and two-dimensional chaotic map (MOTDCM) that has a wider hyperchaotic interval, a larger maximum Lyapunov exponent, and more complex nonlinear dynamics than most existing chaotic systems. Using the hyperchaotic sequences generated by the MOTDCM, a novel image encryption algorithm with different structures is proposed, in which shuffling and diffusion are carried out simultaneously from the perspective of the whole input image. Simulation results and a comparative analysis show that the proposed encryption algorithm has a large key space, high sensitivity to the secret key, and good statistical ciphertext properties. It has a better diffusion effect than existing algorithms and meets the imposed security requirements within only one round of operation, with a reduction in algorithm complexity and an improvement in encryption efficiency. Experimental results demonstrate that this encryption algorithm has good performance and can resist chosen-plaintext attacks and known-plaintext attacks effectively.