A Novel Intrusion Detection Model Using a Fusion of Network and Device States for Communication-Based Train Control Systems
Round 1
Reviewer 1 Report
The manuscript presents the new intrusion detection method for communication-based train control system. The proposed method integrates the status of networks with device states using the HMM classifier. The research is verified by the experimental results. The results show that the proposed IDS can effectively prevent the more serious consequences of attacks on CBTC. Nonetheless, there are several aspects that require improvements:
1) I think that the Introduction of the paper is too large, and authors need to add a separate section in this paper - "Related Works".
2) I recommend adding an analysis of the following papers to the Related Works section:
- Gao B., Bu B. A Novel Intrusion Detection Method in Train-Ground Communication System. IEEE Access, 2019, 7, 178726-178743.
- Melaragno A., et al. Rail radio intrusion detection system (RRIDS) for communication based train control (CBTC). In proc. IEEE International Conference on Intelligent Rail Transportation (ICIRT), 2016, pp. 39-48.
- Zhang W., Bu B., Wang H. An Intrusion Detection Method of Data Tampering Attack in Communication-Based Train Control System. In proc. IEEE Intelligent Transportation Systems Conference (ITSC), 2019, pp. 345-350.
3) The authors should check English, for example grammar errors in Lines 8, 22, 36, 39, 68, etc.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In this paper, the authors presented 'A Novel Intrusion Detection Model Using a Fusion of Network and Device States for CBTC Systems'. There are several issues with this paper. The English language needs significant improvement. The abstract should contain numeric values. Authors are not consistent for example, authors sometimes write Cyber Physical Systems (CPS) and Intrusion detection system (IDS), the first alphabet should be either capital or small. Please check for similar issues. References for most of the text are missing for example 'In March of 2014, about 60 computers of the Metro system in Seoul was 25 infected'. References are outdated, please improve it. Conclusion is sloppy.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Review of manuscript electronics-684333 titled: "A Novel Intrusion Detection Model Using a Fusion of Network and Device States for CBTC Systems".
Overall Comments:
Topic is interesting, and the formulation of the proposed approach technically sound. Authors provide adequate context and background information. Overall outline and flow is good. Summarize shortcoming and technical challenges that this paper will be addressing in a table at the end of section 2 How are the scenarios selected? Provide an overall flow of the processing steps for the experimentation resultsTechnical/Formatting Comments:
Please use smaller paragraphs Please invite a native English speaker to proofread the manuscript, as several corrections in grammar and syntax need to be made Make figures bigger and axis labels largerAuthor Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Paper is revised significantly. I would recommend for publication.
Reviewer 3 Report
Review of manuscript electronics-684333.V2, titled: "A Novel Intrusion Detection Model Using a Fusion of Network and Device States for CBTC Systems."
Overall Comments:
The authors have adequately addressed most of our prior comments and recommendations. Other than minor edits mostly on grammar, which could be addressed prior to the final version, we'd like to recommend this paper for publication.