A Secure, Lightweight, and Anonymous User Authentication Protocol for IoT Environments

Round 1

Reviewer 1 Report

Thank you very much for this valuable contribution. The article is well written except for some minor grammatical errors and necessary spell-checking. Please, make sure that the variables in the formulas are correct for both, your own and those taken from the literature (especially Rajaram et al.). As you can see in the attached PDF document, there are a lot of inconsistencies and errors in this part.

I specifically like the systematic evaluation of the proposed scheme against existing schemes. To further improve the document, I suggest a more concise description of the targeted devices in the introduction and in Section 7 (performance analysis) as the envisioned IoT devices have very specific characteristics (e.g., smart card reader) that are not generally applicable. The devices' constraints should be described e.g. in terms of RFC7228 (or RFC7228bis, respectively).

Comments for author File: Comments.pdf

Author Response

We would like to thank the reviewers for their valuable suggestions that helped us to improve the quality, correctness, presentation and readability of the revised paper (sustainability-1317755). We have taken all the comments into consideration in the revised manuscript as we explained below. We hope the reviewers will be satisfied with the revisions made. To help with the review, we have also highlighted all the changes we have made to the original submission. Please find the attached pdf file.

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper proposes a secure, lightweight, and anonymous user authentication protocol for IoT environments. It begins with an introductory section, which includes the authors' motivation, a justification for the use of the Doley-Yao adversary model, and a description of the paper's main contributions. The second section gives a brief overview over related work. Section 3 presents a review of Rajaram's authentication scheme, which is followed by a section containing a cryptanalysis of that scheme. The fifth section proposes a novel scheme which promises to be more secure and lightweight. In section 6, the authors discuss a security analysis of the proposed scheme. Section 7 provides an analysis of the proposed scheme's performance, and the eighth section provides some very brief conclusions.

Comments and Recommendation

Overall, the paper contains clearly motivated and relevant research following an appropriate methodology, the results of which are appropriately presented and discussed. The paper is very well written and includes good figures and tables which help illuminate the research. However, the paper contains some minor shortcomings, which are described in the following.

An aspect of the applied methodology is described in a subsection of the introduction, namely the adversary model used. It would be better if this were moved to a later, perhaps separate section on methodology.

The methodology used by the authors appears sound and appropriate. The paper could benefit from some additional information about why BAN logic, real-or-random (ROR) model, and the AVISPA simulation were chosen, what their purpose is and how they work. The same can be said about the different attack types analysed in the paper. Why were these chosen? Are they comprehensive? Were others omitted, and if so, why? This could be addressed in combination with the previous recommendation.

The descriptions of the different phases and attacks and in sections 3, 4, and 5 are very dense and could benefit from being rewritten to use more plain language instead of an overreliance on notation. The figures used to describe the phases of the proposed approach are very helpful. This is especially important since the authors plan to publish in Sustainability, which is a journal with a broad readership from different disciplines who may not all be comfortable parsing sections densely filled with this kind of notation.

Again, in relation to the target journal Sustainability, the authors should make clearer the potential impact of their proposed protocol with regards to sustainability. That means, they should translate the computation cost advantage of their protocol into tangible terms: What would it mean in energy savings if their protocol was widely adopted?

Finally, an outlook to future work is missing and should be added.

In summary, the paper should be considered for publication after the minor revisions suggested above.

 

Author Response

We would like to thank the reviewers for their valuable suggestions that helped us to improve the quality, correctness, presentation and readability of the revised paper (sustainability-1317755). We have taken all the comments into consideration in the revised manuscript as we explained below. We hope the reviewers will be satisfied with the revisions made. To help with the review, we have also highlighted all the changes we have made to the original submission. Please find the attached pdf file.

Author Response File: Author Response.pdf

Reviewer 3 Report

Summary:

The study proposes a novel authentication scheme that resolves some security problems found in previous works. The paper claims that the authors found some vulnerabilities with Rajaram et al.'s protocol to various attacks, including off-line password guessing, impersonation, and privileged insider. The paper shows the proposed method and compares it against several related works. 

 

 

Comments:

• The paper shows and compares against Rajaram et al.'s work without thoroughly highlighting the reason for choosing this particular work. 
• The motivation for the work needs more clarification since the paper motivates based on the shortcomings of previous work rather than the need for secure and privacy-preserving protocol.
• Regarding the adversarial model, the use of the Dolev-Yao (DY) adversary model [12] and Canetti and Krawczyk (CK) adversary model [16] is not justified in the paper. Why do the authors choose these models for their analysis? Are there real-world applications where such threat models exist?  
• The related work and the description of the proposed method are well-written and described. I appreciate the authors' efforts in those sections.
• I believe the security analysis of Rajaram et al.'s work (section 4) is slightly thin and requires more highlights and theoretical proof. 
• The comparison with related work is conducted on the works [11, 17, 18, 19, 20, 21, 22, 23, and 24], which is great. However, why does the security analysis is done only on Rajaram et al. [11]?   

 

Author Response

We would like to thank the reviewers for their valuable suggestions that helped us to improve the quality, correctness, presentation and readability of the revised paper (sustainability-1317755). We have taken all the comments into consideration in the revised manuscript as we explained below. We hope the reviewers will be satisfied with the revisions made. To help with the review, we have also highlighted all the changes we have made to the original submission. Please find the attached pdf file.

Author Response File: Author Response.pdf

Reviewer 4 Report

Authors of this paper analyzed Rajaram et al.’s scheme [11] and found this scheme is vulnerable to off-line password guessing, impersonation, privileged insider, and known session-specific temporary information attacks, and does not provide user anonymity and untraceability.

Afterwards, the authors proposed a secure, lightweight, and anonymous authentication protocol, which uses only hash and exclusive-or operations, making it suitable for IoT environments.

 

Overall the paper is well written -except few paragraphs that I could not understand- and the idea is well elaborated. It is also good to follow-up and improve other researchers work.

 

Since this is an improved version of Rajaram et al.’s scheme [11], I think it is neccesary to include a link to your working code. Thus allowing the original reseachers and other researchers to further improve and study your proposal. This will also add more credibility to this paper.

 

I would also suggest to include the following omitted state-of-art works:

https://doi.org/10.1016/j.ipm.2021.102526

https://doi.org/10.3390/electronics10151787

https://doi.org/10.3390/fi11120251

 

Author Response

We would like to thank the reviewers for their valuable suggestions that helped us to improve the quality, correctness, presentation and readability of the revised paper (sustainability-1317755). We have taken all the comments into consideration in the revised manuscript as we explained below. We hope the reviewers will be satisfied with the revisions made. To help with the review, we have also highlighted all the changes we have made to the original submission. Please find the attached pdf file.

Author Response File: Author Response.pdf

Round 2

Reviewer 4 Report

I still think that the working code should be shared (the implementation sor code and not latex as the authors understood). Otherwise, I see no reason to withhold acceptance.

Author Response

Dear Sir,

Thank you very much for your comment.

In this paper, we theoretically presented the security weaknesses of Rajaram et al’s scheme and proposed the improved scheme. We conducted security analysis of the proposed scheme using the AVISPA tool and MIRACL library. The AVISPA code is shown in Figure 8, and the MIRACL library is referred to as [47] in the manuscript. Overall, we did not implement our scheme using working code. In the future, we plan to implement our scheme in practice as we described in lines 463-464.

Best regards,