How Can We Achieve Query Keyword Frequency Analysis in Privacy-Preserving Situations?

Round 1

Reviewer 1 Report

The paper propose a new scheme KFA-PEKS which improves PEKS with KFA. PEKS with KFA was first proposed by [24] but under a single server setup (not immune to KGA). The author heavily relied on the scheme in [22] to construct PEKS in distributed systems, which uses DT-PKC. The novelty comes from using timestamps to control the security deadline on query trapdoors, such that the KFA is private wrt the user's data. The separate servers for matching and KFA allows immunity to KGA. Overall, the paper focuses on an important problem. The solution has incremental technical contribution. The scheme is novel and effective. However, the presentation and English language needs improvement. I recommend Acception after revision.

There are many minor errors. For example, boneh -> Boneh; trpadoor -> trapdoor. It needs more proofreading. 

The notation system is too chaotic to follow.  It needs simplification.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The core proposal of the paper is combining searchable encryption with keyword frequency analysis. The authors demonstrate that their scheme is unique in achieving multi-keyword search, resistant to Keyword Guessing Attacks (KGA), and highly practical and applicable.

In the Section Prelimaries, please give the references of the preliminary knowledge.

Please correct some typos, too.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The review is in a separate file.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

The authors have incorporated my suggestions into the latest version of the paper. The paper is now ready for publication. After that, it is up to cryptanalysts to judge and evaluate the paper's content.

However, there is one more important observation.
To fully understand a paper, it may be necessary to take tables and algorithms from other papers, possibly with some modifications. In such cases, however, it is essential that the reference is precise, and it is not sufficient to refer only to the reference number. It can take many ways. For example:

- For Page 4, Table 1. Immediately after the table: Source: [22], Table 1: Notations and terminologies

- For Page 5, Algorithm 1. Subset Decision Mechanism. Before Input: Source: [22], Algorithm 1 Subset Decision

 

The Minor revision is recommended.

Author Response

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Author Response File: Author Response.docx