Proxy Signature-Based Management Model of Sharing Energy Storage in Blockchain Environment

Round 1

Reviewer 1 Report

The authors propose a proxy signature management model for sharing energy storage, by exploiting the characteristichs of the blockchain technology.

I think the paper is well written and organized. Also the topic is extremely interesting because it looks at sustainability, which is one of the main challenges of our era.

However, I believe that small changes could improve its overall quality. They are listed below:

1. In subsection 3.1 you briefly define the background of the blockchain technology. Please add some references to reinforce this part. I think the 2 references [R1,R2] below are extremely significant in adding value and credibility to this subsection because they point out the fundamentals of the blockchain. 

[R1] Christidis, K. and Devetsikiotis, M., Blockchain and Smart Contracts for the Internet of Things, IEEE Access (2016).

[R2] Casino, F. et al., A systematic literature review of blockchain-based applications: Current status, classification and open issues, Telematics and Informatics (2019).

2. The literature review by Andoni et al. [R3] is a point of reference for what concerns the application of the blockchain technology in the energy sector. In [R3], the authors detect the main challenges and opportunities about this topic. Please, by citing [R3] make a brief discussion about which challenges and opportunities, suggested by [R3], are addressed in your paper. It could add even a great value to the contribution of your interesting paper.

[R3] Andoni et al., Blockchain technology in the energy sector: A systematic review of challenges and opportunities, Renewable and Sustainable Energy Reviews (2019).

3. In your paper, you say that the stored energy can be you used in three different fields: residential users, industrial users, power grid. I think that an additional field can be considered. As stated by Astarita et al. [R4], a recent trend concerns the possibility to use the blockchain technology also to guarantee the right matching between supply and demand in the case of electric vehicles recharging. Please, referring to [R4], explain if and how the model you propose can facilitate the safe sharing of stored energy for recharging electric vehicles. A brief and concise discussion is enough. 

[R4] Astarita, V. et al., A Review of Blockchain-Based Systems in Transportation, Information (2020) 

4. Please, Figure 2 should be better explained within the text. In particular I would like the leaf nodes of the schema to be better justified and discussed.

5. Make a careful check of the text because there are some typos.

E.g.:

line  392: "public key y can be obtain" should be "public key y can be obtained"

line 393: "the group (y,p,g) can be query publicly" should be "the group (y,p,g) can be queried publicly"

6. Please, extend the conclusions, by adding something about the possible future developments of your study. 

Author Response

Many thanks for the comments and suggestions. We have carefully revised the paper to incorporate the required changes, and highlighted main changes as marked in 'red' color in the revised manuscript. The details are given in WORD FILE below. 

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper is just once more application of blockchain technology.

What is needed:

1) more disussion on the real life applicability of proposed solution

2) more references , because it is research paper

3) the decision tree should be presented professionally, please, use professional software for decision tree drawing, or just transform it into block schema, or process diagram.

 

Author Response

Many thanks for the comments and suggestions. We have carefully revised the paper to incorporate the required changes and improve the quality and writing of the manuscript. The highlighted main changes as marked in 'red' color in the revised manuscript. The details are given in WORD FILE below.

Author Response File: Author Response.pdf

Reviewer 3 Report

The paper titled "Proxy Signature Based Management Model of Sharing Energy Storage in Blockchain Environment" is organized in a good way; however, some flaws are still existing. The authors are presenting a new way of the signature mechanism using a proxy. It is a quite interesting approach. Nevertheless, is it possible to compare this solution with other concepts? What is the measured cost and energy reduction (if any)? I cannot see hard data taken straight from the mentioned simulator compared with other already known states of the art. The authors are mentioning some simulations, but the results of these simulations are not presented.

Other issues are as follows:
1) SES acronym is not defined in the text in the place of the first usage (the abstract should be not counted as a place of the definition of this acronym).
2) In lines 96, 99, and 105, I suggest adding some bullets to make these three types of resources more visible in the article.
3) In lines 135 and 145 - the same as in suggestion 2).
4) Figure 2 should be placed after the first reference in the text. In this case, after the last paragraph of Section 2.
5) Since rest sentences (paragraphs) are constructed as they are right now, the line 191 should ends with dot "." not a colon ":".
6) In lines 225, 229, 235, 240, and 245, the authors describe each step of the transaction process. These steps are called "1", "2", "3", "4", and "5" in the text, however, they are called also "S1", "S2", "S3", "S4", and "S5" in the Figure 3, respectively. It should be normalized. I suggest using the names shown in Figure 3.
7) Names of sections and subsections should start not in the last lines of the page - see, for example, Section 3.3 or Section Conclusion.
8) I suggest to put in the italic font the names of each proxy signature mechanism (lines 303, 320, 333, and 346).
9) Line 305, there should be used the reverse order for "p of" (it should be "of p").
10) All variables used in the text should be given in the italic font.
11) What does it mean "large enough prime number"? It should be clearly explained.
12) Line 309 - what is it "Z"? It should be explained that even it is well known in the literature.
13) Number of sections "4 Case Study" and "5 Conclusion" should be renumbered since right now, there are two sections of number 4!

Author Response

Many thanks for the comments and suggestions. We have carefully revised the paper to incorporate the required changes and improve the quality and writing of the manuscript. The highlighted main changes as marked in 'red' color in the revised manuscript. The details are given in WORD FILE below.

In the revised manuscript, more cases are added and discussed, including the digital signature process based the traditional ElGamal digital signature mechanism which is used to make comparison with the one based on proposed method, and the consensus process based on the traditional non-agent method and the proposed principal-agent model with proxy signature mechanism. In the case study of the manuscript, the digital signature process of a bidding message on the blockchain of sharing energy storage is the first application scenario for the proposed solution. By the proposed proxy signature mechanism, the digital signature power pf delegation nodes is tranfered to the proxy node, and the proxy node can achieve the release of the bidding message even if the delegation nodes are faulty or off-line, which makes sure the real-time response for the market. However, the principal-agent model is incomplete because the online delegation on the blockchain cannot be realized without the proxy signature mechanism. On the other hand, the role of the proposed method in the concensus process based on practical Byzantine fault tolerance is demonstrated because it is another typical application scenario. According to the case study, we can find out that the stability of network can be enhanced because the proxy nodes deployed in the professional servers of operators may be healthier and more robust than ones deployed in the servers of owners. Moreover, the effeiciency and speed of consensus process can be improved due to the reduced amount of the nodes that need to multicast messages by using the proposed method.

In conclusion, the proposed proxy signature mechanism achieves the transfer of digital signature power, which is difficult to be solved by the traditional digital signature mechanism, on the blockchain, matching with the off-line principal-agent management model. The quantitative measurement about the cost and energy reduction needs to further study based on more data. The revised and added parts about the cases are shown in WORD FILE as follows.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The paper titled "Proxy Signature Based Management Model of Sharing Energy Storage in Blockchain Environment" was significantly improved, and now it can be published.