A Low-Complexity Start–Stop True Random Number Generator for FPGAs

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

A true random number generator, including a digital chaotically oscillating autonomous Boolean network as a source of entropy, characterized in that the digital chaotically oscillating autonomous Boolean network includes three logical elements connected to each other, the first of which is a two-input “exclusive” logical element or" or "exclusive or-not", the second is a two-input logical element "exclusive or" or "exclusive or-not", and the third logical element has three inputs and one output and implements the logical function "counting ones", in which its the output is set to a logical one if no more than one of its inputs has a logical one, otherwise a logical zero is set, while the output of the first two-input logical element is connected to the first input of the second two-input logical element and to the second input of the third logical element “counting ones” ", the output of the second two-input logical element is connected to its second input, to the second input of the first two-input logical element and to the third input of the third logical element “counting ones”, and the output of the third logical element “counting ones” is connected to its first input, to the first input the first two-input logic element and with the output of the entire network.

The numerical simulation of an exactly solvable problem made it possible to evaluate the quality of the multiplicative multipliers recommended in the work. generator throughout its entire period, as opposed to a limited interval for the tests performed. Some groups of multipliers are noted, the use of which in the PSM method can lead to errors.

How does the random number generator choose? Describe your generator's random number selection algorithm. Why is it better for and more effective than those described and developed. Describe where exactly your random number generator can be used.

Comments on the Quality of English Language

English at a high level.

Author Response

Thank you for the reviews. We appreciate the time the reviewer took and the valuable feedback they provided.

Comment:

A true random number generator, including a digital chaotically oscillating autonomous Boolean network as a source of entropy, characterized in that the digital chaotically oscillating autonomous Boolean network includes three logical elements connected to each other, the first of which is a two-input “exclusive” logical element or" or "exclusive or-not", the second is a two-input logical element "exclusive or" or "exclusive or-not", and the third logical element has three inputs and one output and implements the logical function "counting ones", in which its the output is set to a logical one if no more than one of its inputs has a logical one, otherwise a logical zero is set, while the output of the first two-input logical element is connected to the first input of the second two-input logical element and to the second input of the third logical element “counting ones” ", the output of the second two-input logical element is connected to its second input, to the second input of the first two-input logical element and to the third input of the third logical element “counting ones”, and the output of the third logical element “counting ones” is connected to its first input, to the first input the first two-input logic element and with the output of the entire network.

Answer:

It seems that this comment concerns a different article. In this work, we do not use the chaos phenomenon but phase fluctuations of ring oscillators, i.e., a non-deterministic mechanism.

Comment:

The numerical simulation of an exactly solvable problem made it possible to evaluate the quality of the multiplicative multipliers recommended in the work. generator throughout its entire period, as opposed to a limited interval for the tests performed. Some groups of multipliers are noted, the use of which in the PSM method can lead to errors.

Answer:

We do not conduct numerical simulations in this work and do not use multiplicative multipliers. The presented results concern the implementation of the proposed generator in real systems from various manufacturers. Since we use a non-deterministic phenomenon, the sequences produced are not periodic.

Comment:

How does the random number generator choose? Describe your generator's random number selection algorithm. Why is it better for and more effective than those described and developed. Describe where exactly your random number generator can be used.

Answer:

In the paper, after Figure 3, we have explained why the solution with additional phase detectors was chosen.

 

 

Reviewer 2 Report

Comments and Suggestions for Authors

This paper “A Low-Complexity Start-Stop True Random Number Generator for FPGAs” presents an innovative design of a low-complexity start-stop true random number generator (TRNG) that exploits jitter in ring oscillators (ROs). The approach includes phase detectors to enhance entropy collection and utilizes SHA-1 for online post-processing of raw bits. The TRNG passes all statistical tests described in NIST SP 800-22 and SP 800-90B, and produces random bits on demand, improving security by avoiding continuous operation. The proposed TRNG is implemented across various FPGA technologies and shows promising results. Overall, the paper is well-written and presents significant contributions to the field. However, there are areas that require improvement before it is ready for publication.

1. Writing Quality

Grammar and Writing Style: The overall language of the paper is clear and understandable. However, there are some grammatical errors and awkward phrasings that need correction. For example, the abstract could be more concise and direct. Proofreading by a native English speaker or a professional editor is recommended to enhance clarity and readability.

Structure and Flow: The paper is well-structured, with a logical progression from introduction to conclusion. However, the transitions between sections could be smoother. Improving the coherence between paragraphs, especially in the technical solution and results sections, would strengthen the paper.

2. Innovation

Novelty: The proposed use of phase detectors to increase entropy and the start-stop operation mode for enhanced security are notable innovations. These contributions are clearly significant and have practical implications for TRNG design.

Practical Relevance: The method's applicability across various FPGA technologies and its potential use in cryptographic systems demonstrate its practical relevance and usefulness.

3. Technical Approach

Design and Implementation: The technical approach is sound, and the design is well-explained. The use of only two ROs and additional phase detectors is a clever way to increase entropy without significantly increasing complexity.

Experimental Validation: The experimental results are thorough and convincingly demonstrate the effectiveness and reliability of the proposed TRNG. The statistical tests and comparisons with existing methods are well-presented and support the authors' claims.

4. Results and Discussion

Results Sufficiency: The results are comprehensive and detailed, covering various aspects of the TRNG's performance. The statistical analysis is robust, and the discussion of results is thorough.

Depth of Discussion: While the discussion is detailed, it could benefit from additional insights into the potential limitations of the proposed method and suggestions for future work. Highlighting specific areas for improvement or further research would add value to the paper.

5. References

Format: The references are generally well-cited, but there are inconsistencies in the formatting. Ensure all references adhere to the journal's guidelines. Some references may need reformatting to match the required style.

Coverage: The references cover a broad range of relevant literature, but adding more recent publications could provide a more comprehensive background and context for the current work.

 

Suggestions for Improvement

Grammar and Expression:

Ø  Conduct a thorough grammatical review to correct errors and improve phrasing.

Ø  Simplify complex sentences to enhance readability.

Ø  Ensure smooth transitions between sections and paragraphs for better coherence.

Technical Details:

Ø  Expand on the discussion of the method's novelty and unique advantages.

Ø  Include potential limitations and areas for future research in the discussion section.

References:

Ø  Standardize the reference format according to the journal's guidelines.

Ø  Update the reference list with recent and relevant publications.

Conclusion

The paper makes a significant contribution to the field of TRNG design, with its innovative approach and practical relevance. The experimental validation is robust, and the results are compelling. By addressing the identified areas for improvement in writing quality, technical details, and references, the paper can reach a level of excellence suitable for publication.

 

Recommendation: Accept with minor revisions.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The overall language of the paper is clear and understandable. However, there are some grammatical errors and awkward phrasings that need correction. For example, the abstract could be more concise and direct. Proofreading by a native English speaker or a professional editor is recommended to enhance clarity and readability.

Author Response

Thank you so much for the review. We truly appreciate the time taken by the reviewer and the invaluable feedback that has been provided. Your input is greatly valued and helped us improve our paper.

 Comment:

This paper “A Low-Complexity Start-Stop True Random Number Generator for FPGAs” presents an innovative design of a low-complexity start-stop true random number generator (TRNG) that exploits jitter in ring oscillators (ROs). The approach includes phase detectors to enhance entropy collection and utilizes SHA-1 for online post-processing of raw bits. The TRNG passes all statistical tests described in NIST SP 800-22 and SP 800-90B, and produces random bits on demand, improving security by avoiding continuous operation. The proposed TRNG is implemented across various FPGA technologies and shows promising results. Overall, the paper is well-written and presents significant contributions to the field. However, there are areas that require improvement before it is ready for publication.

Answer:

Dear Reviewer,

I wanted to express my sincere gratitude for the time you dedicated to thoroughly reviewing our article. Your feedback and insightful comments are incredibly valuable to us, and we truly appreciate the care and consideration you put into providing constructive suggestions. Your contribution has been immensely helpful, and we are grateful for your dedication to improving our work.

Comment:

1. Writing Quality

Grammar and Writing Style: The overall language of the paper is clear and understandable. However, there are some grammatical errors and awkward phrasings that need correction. For example, the abstract could be more concise and direct. Proofreading by a native English speaker or a professional editor is recommended to enhance clarity and readability.

Structure and Flow: The paper is well-structured, with a logical progression from introduction to conclusion. However, the transitions between sections could be smoother. Improving the coherence between paragraphs, especially in the technical solution and results sections, would strengthen the paper.

 Answer:

We greatly appreciate your thoughtful comment. As non-English speakers, we are particularly thankful for feedback of this nature. The grammar has been diligently improved, and efforts have been made to enhance the continuity and coherence between the sections of the article. Numerous sentences have been rewritten to ensure better readability and flow. It is our hope that these revisions will make the article more enjoyable and coherent for all readers.

Comment:

2. Innovation

Novelty: The proposed use of phase detectors to increase entropy and the start-stop operation mode for enhanced security are notable innovations. These contributions are clearly significant and have practical implications for TRNG design.

Practical Relevance: The method's applicability across various FPGA technologies and its potential use in cryptographic systems demonstrate its practical relevance and usefulness.

Answer:

Thank you very much for your insightful comments.

Comment:

3. Technical Approach

Design and Implementation: The technical approach is sound, and the design is well-explained. The use of only two ROs and additional phase detectors is a clever way to increase entropy without significantly increasing complexity.

Experimental Validation: The experimental results are thorough and convincingly demonstrate the effectiveness and reliability of the proposed TRNG. The statistical tests and comparisons with existing methods are well-presented and support the authors' claims.

Answer:

Thank you for taking the time to share your insightful comment with us. Your feedback is truly valuable to us. We have extended the article to include theoretical considerations, and we believe that this addition will significantly enhance the understanding and depth of our work.

Comment:

4. Results and Discussion

Results Sufficiency: The results are comprehensive and detailed, covering various aspects of the TRNG's performance. The statistical analysis is robust, and the discussion of results is thorough.

Depth of Discussion: While the discussion is detailed, it could benefit from additional insights into the potential limitations of the proposed method and suggestions for future work. Highlighting specific areas for improvement or further research would add value to the paper.

Answer:

We are truly grateful for your insightful comment, which has made a significant contribution to improving the quality of our article. As a result of your input, we have expanded the discussion to encompass potential disadvantages of our solution and have outlined the directions for future work. Your valuable input has been instrumental in furthering the depth and breadth of our article.

Comment:

5. References

Format: The references are generally well-cited, but there are inconsistencies in the formatting. Ensure all references adhere to the journal's guidelines. Some references may need reformatting to match the required style.

Coverage: The references cover a broad range of relevant literature, but adding more recent publications could provide a more comprehensive background and context for the current work.

Answer:

I greatly appreciate your kind attention. The bibliography has been meticulously reformatted and supplemented. Your support is truly valuable.