Optimizing RTL Code Obfuscation: New Methods Based on XML Syntax Tree
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis paper is well written. presented, and the results were obtained at a satisfactory level. However, I noticed a few points.
1. The title is too generic; it must change to a specific title that reflects the findings of the proposed method.
2. RTL code obfuscation is the technique proposed in this paper; however, the vendors of the hardware design might have their own strategies to protect their RTL.
If this is considered to adopt the proposed method of RTL code obfuscation, how does the EDA tool behave with the encrypted code using XML? What are the challenges that must be taken into account if RTL code is written with XML, and how will the EDA tool simulate it functionally? And what are the challenges that are associated with it if it goes for verification?
3. It is recommended to add a few recent articles in Section 2: Related Work. As all the literature is not recent except for one,
4. Layout Obfuscation: Information Removal: Author claims: Remove all spaces and useless comments in the RTL code. The original RTL code is then replaced with these meaningless strings. All the spaces are removed during the obfuscation process to make the structure of the code more compact and difficult to read. If you do this, there are more chances of getting an error if the file is not decrypted correctly, and it makes things difficult.
5. In the parameter obfuscation method, it is recommended to present the steps one after another for flow by taking any example to retain authenticity and gain the faith of the readers.
6. Critical Path Obfuscation: Please list out the benefits and drawbacks of the method if it is applied to any design with respect to the critical path or any other parameter.
Comments on the Quality of English Language
As far as I know, it is fine; however, the journal might look into the English language proficiency test.
Author Response
Dear reviewer，
We feel great thanks for your professional review work on our article.Regarding our response to your comments, please review the detailed response in the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors1- Lack of formulas and relations to show a scientific work.
2- It is expected to find more references related to this work.
3- Besides the proposed idea's advantages and disadvantages, coding and decoding complexity and the risk of missing the main data is another problem.
4- How much is it applicable for large-scale and small-scale scenarios? Does it have a similar impact in different scenarios?
5- The required bandwidth to transmit the additional data or time required to change and reshape the data, and additional consumed power should be evaluated.
Comments on the Quality of English LanguageMinor comments are needed.
Author Response
Dear reviewer，
We feel great thanks for your professional review work on our article.Regarding our response to your comments, please review the detailed response in the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper discusses research on RTL code obfuscation based on XML syntax tree. The authors propose four targeted obfuscation methods: layout obfuscation, parameter obfuscation, critical path obfuscation, and code increment obfuscation. These methods are applied based on the XML syntax tree generated by parsing the RTL code. An obfuscation tool is developed to assess the performance and effectiveness of the obfuscation methods. The experimental results show that the proposed methods have higher practicability, reliability, and obfuscation coverage, with the preservation of compiler-indicative comments. The obfuscation tool is compared with another tool, VCS, and it is found that the proposed methods provide higher obfuscation coverage and preservation of the original project architecture. The research contributes to the field of RTL code obfuscation by providing effective methods for code protection and enhancing the security of intellectual property. Although the paper is interesting, the following comments should be addressed.
-- The introduction effectively emphasizes the significance of securing RTL code within the rapidly advancing field of Integrated Circuit (IC) technology and business cooperation. However, providing specific examples or case studies would strengthen the argument for the importance of code obfuscation in protecting intellectual property.
-- While the related work briefly mentions the distinction between code obfuscation and encryption, it would benefit from a more comprehensive discussion of previous research efforts in RTL code obfuscation. Providing a detailed overview of existing techniques and their limitations would enhance the literature review. To help the authors, I suggest discussing the following recent publications: ‘Full-wave analysis of interconnects in finite substrates with layered media formulation of SVS-EFIE for 3d composite metal-dielectric structures’, and ‘Design of a high-efficiency dual-helical antenna for microwave plasma sources’.
-- The paper should provide a step-by-step explanation of the proposed obfuscation methods based on the XML syntax tree.
-- Explore and develop more advanced and sophisticated obfuscation techniques to further enhance the security of RTL code.
-- Investigate the impact of obfuscation techniques on performance metrics, such as area, timing, and power consumption.
-- Explore the potential of dynamic obfuscation techniques that can dynamically modify the obfuscated RTL code during runtime.
-- Investigate the practical applications of RTL code obfuscation in real-world industrial scenarios.
-- Explore the integration of obfuscation techniques with other security measures at different layers of the design, such as physical security and cryptographic methods.
Comments on the Quality of English LanguageMinor editing of the English language is required.
Author Response
Dear reviewer，
We feel great thanks for your professional review work on our article.Regarding our response to your comments, please review the detailed response in the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have addressed all of my comments from the previous review, and I have no further comments on the manuscript.
Reviewer 2 Report
Comments and Suggestions for AuthorsAll comments are addressed carefully.
No new comment.
Comments on the Quality of English LanguageIt is good in an acceptable style.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe authors revised the paper carefully. So, I have no further comments. My recommendation is to accept the paper at this stage.
