Security-Enhanced Three-Dimensional Image Hiding Based on Layer-Based Phase-Only Hologram Under Structured Light Illumination

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript develops a three-dimensional (3D) image hiding and encryption method by combining a layer-based phase-only hologram under structured light illumination with a chaotic encryption and a digital image watermarking technology. They used the proposed method to enhance the security of encryption system. It is an interesting method to optimize the 3D image hiding system in practical applications. Simulation results and performance analysis are given. Overall, the authors depicted the processing procedures of the proposed method and made some simulations to verify the feasibility and effectiveness of the proposed method. The manuscript can meet the standards of Photonics. I think it can be acceptable for publication after minor revision. 1. It is suggested to further discuss some of the cipher text-only attack, known plaintext attack or chosen plaintext attack. 2. Authors should compare their method with others well-known techniques in 3D image hiding field. Minor revision is there. Please carefully address above concerns in the revised manuscript. Then the paper may be accepted.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript proposes a security-enhanced 3D image hiding method based on layer-based phase-only hologram (POH) under structured light illumination combined with chaotic encryption and digital image watermarking technology. The method encodes the original 3D plaintext image into a layer-based POH, further encrypts it with a chaotic random phase mask (CRPM) generated through a piecewise linear chaotic map (PWLCM), and embeds the encrypted phase into a 2D host image using DWT-SVD-based digital image watermarking. The structured light used in POH encoding introduces many optical parameters as supplementary keys, expanding the key space and enhancing key sensitivities. There are several remarks should be addressed.

1.  The manuscript states that the structured light used in the proposed method has many optical parameters that can serve as supplementary keys. Could the authors elaborate on the specific advantages of these optical parameters in terms of enhancing the security of the encryption system compared to other types of keys?

2.  You can provide a more detailed comparison of the key sensitivities before and after the introduction of structured light, supported by experimental data or theoretical analysis.

3. The authors mention that the proposed method has a large key space, but the specific calculation method and theoretical basis for the key space size are not detailed. Could you elaborate on how the key space size was calculated and provide a more in-depth theoretical analysis to support this claim?

4. The manuscript states that the decrypted result exhibits noise-like distribution when any one key has a slight deviation. However, the specific threshold for "slight deviation" is not clearly defined. Specify the exact range of deviation that would lead to a failed decryption and provide corresponding experimental data.

5. The authors suggest that a higher-dimensional chaotic system can be adopted to further improve the level of security.  Provide some specific suggestions or references on how to implement this in the proposed method. Moreover, discussing the potential challenges and solutions in extending the current method to color 3D images?

6.  In the introduction, it is suggested to supplement the introduction of the research status of holography technology in other fields. For example, you can cite "1.  J. Mater. Chem. A 2025, 13, 6009–6019, DOI: 10.1039/D4TA07450E      2.  Crystal Research and Technology, 2025, 2400264. DOI: 10.1002/crat.202400264". These papers can provide a more comprehensive background for the research on holography technology, helping readers better understand the application prospects and research significance of the proposed method.

7. It is suggested to supplement experiments on the impact of different types and intensities of noise on the decryption results, providing a more comprehensive evaluation of the method's anti-noise performance. Providing more experimental data on the influence of different embedding factors on the quality of the ciphertext and decryption results to support the selection of the embedding factor.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

In this manuscript, a security-enhanced three-dimensional (3D) image hiding and encryption method is proposed by combining a layer-based phase-only hologram (POH) under structured light illumination with a chaotic encryption and a digital image watermarking technology. Some concerns are listed as follows.

1. The manuscript should more explicitly distinguish its novelty beyond the authors' prior work (Ref [31]).
2. Supplement CC with objective metrics like Peak Signal-to-Noise Ratio (PSNR) or Structural Similarity Index (SSIM) for decrypted images, especially for the noise attack and filtering attacks.
3. The Conclusion states "apparent security-enhanced effect" and "significantly improved key sensitivities". Explicitly state the magnitude of improvement for key sensitivities.
4. How about the entropy of the ciphertext images?

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Publish

Reviewer 3 Report

Comments and Suggestions for Authors

This paper can be accepted in present form.