Abstract: Abstract: With the rapid development of computer networks and multimedia technologies, the security problem of digital image transmission has become increasingly salient. A hyper-chaotic encryption algorithm was proposed for plaintext associated images. The algorithm employed hyper-chaotic systems with more complex dynamics as a chaotic sequence generator, expanded the key space, and utilized a diffusion-scrambling-diffusion encryption framework. The method performed three-stage processing on the image, of which the depth diffusion improved efficiency using fewer iterations. The scrambling algorithm eliminated the correlation between adjacent pixels in the original image by disturbing the pixel positions. The experiment analyzed and compared the key space size, algorithm efficiency, and anti-plaintext attack capability. The simulation results show that the algorithm has not only larger key space and higher operating efficiency, but also strong plaintext sensitivity, thus effectively resisting differential attacks with great potential for secure communication applications.

Key words: Keywords: image encryption, hyper-chaotic system, plaintext correlation, scrambling, diffusion