Random Numbers Generated Based on Dual-Channel Chaotic Light
Round 1
Reviewer 1 Report (New Reviewer)
Comments and Suggestions for AuthorsComments for author File: 
Comments.pdf
The text is well-written and easy to read and understand. Still, I suggest additional proofreading to make it perfect!
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report (New Reviewer)
Comments and Suggestions for AuthorsThe paper outlines an extensive study on the generation of random numbers using a chaotic system based on semiconductor nanolasers. It represents an innovative approach in the field of photonics and chaos theory, while the topic itself is significant because of its implications in various secure communication and cryptographic systems. Overall, the paper is well structured and written, but could benefit from some smaller improvements.
- Please elaborate where can we expect the biggest benefits of using chaotic system based on NLs, utilized as an entropy source for generating random numbers? Are there are some specific application examples where other entropy sources are not sufficient, perform slow, or are considered a bottleneck, and where chaotic system would be a solution?
- In conclusion section, authors should elaborate on potential future directions for the research (future work).
The paper gives valuable insights into the use of chaotic NLs for RNG, demonstrating significant advancements in the field. I recommend it for publication after addressing my previous comments.
Author Response
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Author Response File: Author Response.pdf
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
1. While the theoretical model is explained, there is a lack of critical analysis regarding its assumptions, limitations, and the implications of these on the study's findings. This discussion should be expanded. The manuscript could be strengthened by a broader series of experiments exploring a wider range of parameter mismatches and injection parameters.
2. A section discussing how the methodology could be scaled or modified for different types and sizes of NLs would be beneficial.
3. The interpretation of results requires further depth. For example, a discussion about why retaining 5-LSBs yields success across all NIST tests while retaining 6-LSBs does not would add valuable insight.
4. The paper lacks an in-depth statistical analysis beyond the passing of NIST SP 800-22 tests. The inclusion of other randomness tests and statistical measures could strengthen the argument for the quality of the RNG.
5. Specifics on how the value of m-LSBs was chosen and the impact of its variation on the quality of the generated randomness require a more thorough examination.
6. The literature review seems focused on works that directly align with the authors' findings. A broader examination of related studies, particularly those with conflicting results or different approaches, would enhance the paper's context.
7. How do the results of this paper compare to other RNGs using different physical phenomena as entropy sources in terms of speed, security, and reliability?
8. There is scant justification for the choice and range of parameters selected for the study. More information is needed on why these parameters are relevant and how they affect the system dynamics and RNG quality.
9. The authors should clarify the theoretical underpinning that allows for the claimed match between NL dynamics and RNG requirements. What specific characteristics of NLs make them suitable for generating randomness?
10. The role of post-processing techniques in generating randomness from NLs seems to be critical. Could the authors elaborate on the possible weaknesses or failures introduced by post-processing? Could the system be optimized to provide true randomness without the need for such intense post-processing?
11. In the case of parameter mismatch and the need to retain different LSBs, the paper should describe the process of determining the optimal number of LSBs to be retained. Is there any empirical formula or technique used to come to these conclusions?
12. On the testing of randomness, while NIST SP 800-22 is a commonly accepted standard, the authors should justify why they selected this suite as opposed to other tests, like the Diehard tests or the TestU01 suite.
13. How sensitive is the RNG’s performance to fluctuations in NL parameters? Are there any error-correction mechanisms in place to address potential deviations?
Comments on the Quality of English LanguageExtensive editing of English language required
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for Authors1) The authors should explain in the abstract what type of distribution density function was expected and what was generated by the system, i.e. whether it was a uniform, Gaussian, etc. probability density function.
2) In figure 1, each output signal from each block must be related to its equation.
3) According to the theoretical model illustrated, the generator's output signal is a square waveform.
4) Is the article a simulation or a physical implementation? It is only in the results section that it is explicitly stated that the previous equations were solved numerically using the Fourth-Order Runge-Kutta method. The reader then assumes that the article deals with a computer numerical simulation. Is this correct?
5) Considering that all the blocks have been implemented by simulation, what is the stochastic source? Is the laser signal produced using some kind of random number generator? There is a lack of information on the operation of the scheme used in the simulation. There are only superficial details on each block of the model.
6) For a reader with little experience in the field, the article is confusing and confused.
7) The article should be rewritten in greater detail.
Comments on the Quality of English Languagea) Remove the comma:
...optical chaotic signals, and generate... 11
b) Add a comma:
... operation and the m least... 14
c) Remove the comma:
... parameters, and examine... 20
d) Change the verb form:
...that retains 5-LSBs... to ... that retains 5-LSBs... 23
e) Correct your spelling
...mation verification [1,2]... 31 to ...motion verification [1,2]...
f) Correct the verb
...which is difficult... 41 to ...which makes it difficult...
3) Correct your spelling
...of Tbps... 41 to ...of T bps...
Sorry, I'll stop right there! It has already been demonstrated that the text requires a revision of the grammar rules.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for Authors1. Did the authors realize the circuit shown in Figure 1 by themselves, or it is an off the shelf circuit block? The block diagram is overly simplified. There is no information about the filters that should have been present before the ADCs block. How did the authors sample data without using any filters before the ADCs? Could you please explain this?
2. Why does the p-value at line, 163, 164, compared with 0.0001 rather than 
? Could you please provide a brief explanation?
3. Line 183 mentions sampling, but there is no information on the sampling frequency. Could you please mention the sampling frequency?
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsWhile the theoretical model is explained, there is a lack of critical analysis regarding its assumptions, limitations, and the implications of these on the study's findings. This discussion should be expanded. The manuscript could be strengthened by a broader series of experiments exploring a wider range of parameter mismatches and injection parameters.
1. Consider including specific quantitative metrics to measure the performance of the random number generator. This could include measures of randomness, entropy, and statistical properties of the generated sequences.
2. Provide a comparative analysis of the proposed method with existing random number generators. This could involve comparing the performance of the generated sequences against standard benchmarks and other RNG methods.
3. Conduct a more in-depth statistical analysis of the generated random sequences. This could involve analyzing the distribution properties, autocorrelation, and other statistical tests to validate the randomness and quality of the generated sequences.
4. Provide a more detailed explanation of the methodology used to generate random numbers based on nanolasers, including the specific processes involved in generating complex optical chaotic signals and how high-quality random sequences are obtained.
5. Expand on the simulation results section by providing a more comprehensive analysis of the performance of the proposed random number generator under different conditions and parameters. Include specific details about the random number test suite NIST SP800-22 and how the generated sequences performed in the tests.
6. The conclusion and future work can be improved to provide a clearer and more robust abstract. The paper would benefit from improved clarity and structure, with some sections requiring reorganization for better flow and understanding.
7. The analysis presented in the paper Is insufficient. Both the literature review and the results lack depth and require greater comprehensiveness. Only one result is implemented and simulated in this paper, which is not sufficient. Furthermore, the research methodology needs to be explained in terms of its adoption and requires more in-depth scrutiny and comparisons with previous research. Additionally, the data needs to be validated, and the conclusions and future work need to be improved.
Comments on the Quality of English Language
Moderate revisions
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe authors have revised the manuscript extensively. However, there is a fundamental flaw in the schematic which generates random bits. The author’s response is not satisfactory.
At lines 139 and 140, the authors mentioned “According to the device shown in Figure 1, the rate equations for the chaotic entropy source can be written as follows [41,43].”
These two references 41 and 43 used the rate equations, but there was no block diagram like in Figure 1, as shown below.
Figure 1 shows an analog mixer or multiplier which takes two inputs and outputs their product. There must be a DC value as well as the fundamental frequency and its harmonics. (Please consult the basic operation of analog multiplier)
These multiplier output signals cannot be sampled without first passing through a filter before ADC.
Comments for author File: Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Round 3
Reviewer 3 Report
Comments and Suggestions for AuthorsI don't have any technical requirements. Just a reminder that authors should generate data very carefully; otherwise, statistical analysis is meaningless.
Author Response
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Author Response File: Author Response.pdf
