<p>Due to the rapid advancement of communication technologies and networks, the secure transmission of image information has become increasingly critical, making image encryption an essential technique. Among various approaches, image encryption based on chaotic systems has attracted significant research interest. Although numerous chaotic encryption methods have been proposed, many exhibit limited security. To enhance the security of image encryption schemes, this paper introduces a novel encryption method employing the 3D Sprott K chaotic system. First, the dynamic characteristics of the Sprott K chaotic system are analyzed through phase diagrams, bifurcation diagrams, and Lyapunov exponents (LEs). Subsequently, an image encryption algorithm is designed based on this system. The algorithm incorporates a scrambling stage and two diffusion operations: the Zigzag algorithm is applied to permute pixel positions, while two diffusion processes alter pixel values. Finally, the security performance of the proposed encryption algorithm is thoroughly evaluated. Experimental results demonstrate that the scheme effectively encrypts images and achieves a high level of security.</p>