Review Reports
- Bashar Suhail Khassawneh1,*,
- Issa AL-Aiash2 and
- Mahmoud AlJamal3,*
- et al.
Reviewer 1: Anonymous Reviewer 2: Islambek Saymanov
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis paper proposes a QR code image watermarking algorithm that combines DWT, SVD, and Schur decomposition to enhance watermark robustness under common attacks. By embedding the QR watermark into the LL and HH subbands, the authors claim that the method achieves high NC values under multiple attack types while preserving QR code scannability.
1. The writing quality should be improved by reducing grammatical errors, spelling mistakes, and redundant expressions.
2. The theoretical advantages of Schur decomposition in watermarking should be supplemented, clarifying its differences and complementarity with SVD.
3. A sensitivity analysis of α (embedding strength) should be provided, such as performance curves when α varies from 0.01 to 0.2.
4. The motivation for embedding watermarks separately into the LL and HH subbands should be theoretically explained more clearly, including why the LH/HL subbands are not selected.
5. Comparative experiments with recent deep-learning-based watermarking algorithms should be included to enhance the competitiveness of the method.
6. Two studies related to digital content security also offer valuable insights. The anti-recompression analysis in “Re-cropping Framework: A Grid Recovery Method for Quantization Step Estimation in Non-aligned Recompressed Images” and the robustness enhancement through chaotic structures in “Encrypt a Story: A Video Segment Encryption Method Based on the Discrete Sinusoidal Memristive Rulkov Neuron” can provide broader technical references for strengthening the attack model and security discussion of this paper.
7. When discussing robustness and embedding strategies in the image domain, the paper “Image Steganography in Color Conversion” may be referenced, as its idea of maintaining information stability during color-space transformation aligns methodologically with the DWT–SVD–Schur embedding pipeline of this work.
Author Response
Manuscript Title: Unbreakable QR Code Watermarks: A High-Robustness Technique for Digital Image Security Using DWT, SVD, and Schur Factorization
Manuscript ID: cryptography-4022333
I would like to sincerely thank you for the time, effort, and expertise you dedicated to reviewing my manuscript. Your insightful comments and constructive suggestions have been invaluable in improving the quality and clarity of the paper. I carefully considered each point you raised and revised the manuscript accordingly.
I am grateful for your thoughtful feedback, which not only strengthened this work but also provided me with valuable perspectives for my future research.
Thank you once again for your contribution and support.
All the revisions are included in the attached file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis paper proposes a new watermarking method based on a combination of the discrete wavelet transform (DWT), singular value decomposition (SVD), and Schur matrix factorization to ensure digital image security and protect copyright. The authors used QR codes as watermarks and tested their resilience to various attacks (noise, clipping, compression).
The article requires serious revision due to the incomplete presentation of experimental results (PSNR/SSIM results are missing from the tables) and the ambiguity of some aspects of the methodology.
- The authors did not follow the template of the journal "Cryptography".
- In Section 4.3 (Evaluation Metrics), the authors present the PSNR (Eq. 28) and SSIM (Eq. 30) formulas and emphasize their importance in measuring the "imperceptibility" of the watermark. However, Tables 1, 2, 3, and 4 only present the NC (Normalized Correlation) values. Where are the PSNR and SSIM values? There is no information on how much the image quality has changed after the watermark is placed. Only robustness is shown, but invisibility is not proven. PSNR and SSIM results for all experiments must be included in the tables.
- Algorithm 1 (Line 386) and Algorithm 2 show that α_L and α_H (scaling factors) are used. However, the article does not provide information on how the exact value of these coefficients was chosen (e.g., 0.01, 0.05, or 0.1?) and how this choice affects the results. The authors should provide a deeper theoretical justification for why they chose Schur factorization in addition to DWT and SVD and how it specifically contributes to the efficiency of this algorithm.
- To clearly demonstrate the superiority of the proposed method, a comparative table of numerical results (NC and PSNR) obtained under the same conditions with other modern methods is needed. The current table (Table 5) only lists general terms such as "Good robustness" and the results of other papers separately, making direct comparison difficult.
- The text contains many grammatical errors, incorrect article usage, and inappropriate word combinations. This makes the article difficult to read and understand. The article must be professionally proofread or fully edited by a professional with excellent knowledge of English.
Examples:
Line 43: The phrase "safe and sound" is too colloquial for a scientific article.
Line 58: "An digital watermark" (should be: "A digital watermark").
Line 288: "an scalar multiple" (should be: "a scalar multiple").
Line 310: "an matrix" (should be: "a matrix").
Line 312: "SvD" (lowercase, should be "SVD").
Comments for author File: Comments.pdf
Line 43: The phrase "safe and sound" is too colloquial for a scientific article.
Line 58: "An digital watermark" (should be: "A digital watermark").
Line 288: "an scalar multiple" (should be: "a scalar multiple").
Line 310: "an matrix" (should be: "a matrix").
Line 312: "SvD" (lowercase, should be "SVD").
Author Response
Manuscript Title: Unbreakable QR Code Watermarks: A High-Robustness Technique for Digital Image Security Using DWT, SVD, and Schur Factorization
Manuscript ID: cryptography-4022333
I would like to sincerely thank you for the time, effort, and expertise you dedicated to reviewing my manuscript. Your insightful comments and constructive suggestions have been invaluable in improving the quality and clarity of the paper. I carefully considered each point you raised and revised the manuscript accordingly.
I am grateful for your thoughtful feedback, which not only strengthened this work but also provided me with valuable perspectives for my future research.
Thank you once again for your contribution and support.
All the revisions are included in the attached file.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have addressed the reviewers’ comments thoroughly, and the revised manuscript has been significantly improved. I recommend acceptance.
Reviewer 2 Report
Comments and Suggestions for AuthorsI agree with the responses
Comments on the Quality of English LanguageLine 43: The phrase "safe and sound" is too colloquial for a scientific article.
Line 58: "An digital watermark" (should be: "A digital watermark").
Line 288: "an scalar multiple" (should be: "a scalar multiple").
Line 310: "an matrix" (should be: "a matrix").
Line 312: "SvD" (lowercase, should be "SVD").