To improve the security and efficiency of multi-image encryption, this study proposes a hybrid encryption method that combines interferenceless coded aperture correlation holography (I-COACH) with chaotic modulation and compressed sensing techniques. This method constructs a dual-layer encryption framework that integrates optical and digital processing, thereby overcoming the limitations of single-domain schemes.

In the optical layer, I-COACH is used to encode multiple input images by recording their point spread holograms without interference, providing initial encryption and resistance to physical attacks. Then, resulting hologram is processed using block-wise discrete cosine transform (DCT) to achieve sparsity. Dual chaotic sequences perturb DCT coefficients to enhance key sensitivity and randomness. Finally, compressed sensing is used to achieve secondary encryption while reducing the data volume by 30%, enabling efficient and secure storage or transmission. The experimental results show that the proposed method against differential attacks achieves an average number of pixels change rate (NPCR) of 99.44% and a unified average changing intensity (UACI) of 33.04%, with a ciphertext entropy of 7.9996 bit. Moreover, it exhibits excellent encryption performance in terms of key sensitivity, robustness, and resistance to statistical analysis. This method provides a practical solution for secure image application scenarios such as medical imaging and surveillance.