Fuzzy Keyword Searchable Encryption Scheme Based on Blockchain

Round 1

Reviewer 1 Report

The authors focus on the context of searchable encrypted documents on encrypted cloud data. They propose a fuzzy keyword searchable encryption scheme based on blockchain.   The title, abstract, and keywords fit the manuscript. The related works are timely to date and the methodology is well explained. I would suggest further details on the algorithm because section 4.2 is confusing.

Author Response

Thank you for your suggestions and doubts about the content of my article. Accordingly, I make corresponding modifications and explanations. I hope you can continue to correct me.
The content of Section 4.2 of this paper is explained as follows: The definition of the algorithm is shown in Section 4.2 of this paper, which mainly includes 7 algorithms, namely key generation algorithm (KeyGen), index generation algorithm (BuildIndex), trapdoor generation algorithm (Trapdoor), search algorithm (Search), verification algorithm (Verify), decryption algorithm (Dec) and data update algorithm (Updata). This part describes the general process of the proposed scheme: 1) The data owner first generates relevant keys locally, and on this basis completes data encryption and index construction, and uploads encrypted documents and secure indexes to the cloud server. 2) If data users want to search the encrypted documents on the cloud server, they need to generate the corresponding search trap door and upload it to the cloud server. 3) After receiving the search trap from the data user, the cloud server performs the search operation and returns the search results to the blockchain. 4) The blockchain will perform verification after receiving the search results. If the verification passes, the results will be handed over to the data user, and then the data user will perform decryption. Otherwise, reject the result. Finally, the scheme also supports dynamic data updates, which are performed by the data owner. In addition, the details missing from this section are shown in detail in Section 4.3.

Reviewer 2 Report

The authors proposes a fuzzy keyword searchable encryption scheme based on blockchain, which uses edit distance to generate fuzzy keyword sets and generates a secure index with verification tags for each fuzzy keyword set to verify the authenticity of the returned results. The works are valid. However, there are some issues should be addressed or cleared.

 

1.      In subsection 4.2 in page 6, the key set in step 1 and the encrypted documents set in step 2 have the symbol, please check them.

2.      The authors used ‘Edit distance’ in their scheme. In fact, we care more about the meaning of keywords. Please explain it.

3.      The authors give the performance comparison in Table.4 in page 10. The results would be clearer if the authors could be graphically represented.

4.      The symbols should be italicized, please check the manuscript.

5.      The format of the references should be consistent, please improve them.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

There are some issues need to be described clearly.

 1. The authors used “Edit distance” in their scheme. In fact, we care more about the meaning of keywords. Are there fuzzy keyword searchable encryption schemes based on the meaning of keywords? If so, please give the references, otherwise, please give the reasons.

Author Response

Thanks for your review. In this scheme, the meaning of keywords is the same as the references listed in this paper [15][17][18].   Different keywords are extracted from the plaintext documents, then fuzzy keyword sets are generated for each exact keyword, and secure indexes are constructed.   However, the detailed concept of keywords is not given in the above literature.   In my understanding, keywords are a class of words in a plain text document that not only summarizes the main content of the document, but also distinguishes the document from other documents.