Moving Target Defense for Detecting Coordinated Cyber-Physical Attacks on Power Grids via a Modified Sensor Measurement Expression

Round 1

Reviewer 1 Report

In figure 5, you write in y-axis “Deetecton”, check the spelling.

Clarify how calculate the detection rate

Can you compare the applied method with machine learning algorithms for cyber-physical attack detection

Clarify the type of estimator that you use and compare it with others in literature

Clarify how select the thresholds values to know if there attacks or not

In equation (27), you modify the measured signal by adding “−Δ?(???±??)” , what is the different if we consider measurement noises “e” only, or any random function, is this new contribution 

Clarify the steps of the proposed technique in a flowchart.

Support the assumption of the attack scenarios by references.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper proposes a modified sensor measurement expression for moving target defense strategy to defect coordinated cyber-physical attacks in a Power Grid.

I find the paper interesting, and the statements are proven. 24 simulation strategies are performed. However, the completeness of the test set is not demonstrated. The scalability of the proposed method is also not demonstrated. The results are not compared with other achievements in the field.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

This paper presents a technique for modifying the measurements in a smart grid so that possible coordinated cyberattacks can be detected. The approach is algebraic, based on least-squares optimization, and is interesting with application in real environments.

The main problem with the paper is its poor use of English. Many parts of the text are barely understandable, so the general logic and fitness of the proposal are almost lost and cannot be followed as one would expect. I strongly recommend the authors to rewrite the manuscript and resubmit so that their work can be fairly assessed.

Author Response

Dear reviewer, thank you for your advice.

After being modified by MDPI professional English writing serveice , our article is now resubmitted. The supporting documents can be seen in the attachment.

Thank you sincerely!

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

 Accept in present form

Author Response

Thank you for your review!

Reviewer 2 Report

None.

Author Response

Thank you for your review!

Reviewer 3 Report

A method for detecting supposedly undetectable coordinated attacks to the smart grid is presented in this paper. It is based on a purposely designed change of state in the system so that typical covert attacks are led to be ineffective. The paper is well organized, is clear and there is enough support for the improvements in the proposed technique. A few comments to the authors follow:

1) Explain more clearly the proof of the Theorem in the paper. In particular, the reasoning that lambda is roughly 1, can be equal to 1, or is between 0.8 and 1.2 is really confusing. Since this is the key result in the paper, it should be presented without ambiguity.

2) According to this proof and the previous point, equation (25) is an approximation, not an identity.

3) Reformat Table 2, it is too long.

4) In Figs. 9 and 12, explain the meaning of the axes labels, and their numerical scales.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 3

Reviewer 3 Report

The authors have provided complete and accurate answer to all my previous concerns.