An Architecture for Biometric Electronic Identification Document System Based on Blockchain ^††

Round 1

Reviewer 1 Report

The manuscript titled “An Architecture for Biometric Electronic Identification Document System based on Blockchain” proposes a novel architecture for biometric electronic Identification Document (e-ID) system based on Blockchain for citizens identity verification in transactions corresponding to notary, registration, tax declaration and payment, basic health services and registration of economic activities, among others.

In such a context the authors propose a transaction validation process that exploits a Blockchain system in order to record and verify the transactions made by all citizens registered in the electoral census, which should be grant security, integrity, scalability, traceability and no-ambiguity.

The experimental process adopted by them include the evaluation of the mining time, memory and CPU usage when the number of transactions scale up.

They claim that the proposed architecture, based on the use of smart cards and biometric authentication mechanism, is able to reduce the identity theft for document owner, controlling the e-government services could be accessed by the citizen.

 

Although the manuscript is well written, I suggest a careful re-reading of it in order to fix some minor typos (e.g., "behaivoral" instead of "behavioral" in Section 2.2, “conclusions, remarks and future work” instead of “conclusions, remarks, and future work” in Section 1, and so on).

 

The overall structure of the manuscript does not follow the canonical structure of most literature articles, resulting somewhat unbalanced on the introductory part, with the result of reducing the contents readability.

I suggest to divide the "Introduction" section into two sections, "Introduction" and "Related Work", reserving the introductory section only for a brief overview of the domain taken into account, expanding each concept by using subsections of the "Related Work" section, instead of propose them as unhooked sections of the manuscript.

 

In any case, they should cite and discuss further papers focused on information very close or directly related to the research field taken into account by the authors, i.e., they should add more in-deep information and additional literature references.

 

For the same reasons I previously mentioned in relation to the introductory part, also the presentation of the proposed architecture results very confused.

The authors should avoid to mix literature information with information related to the proposed architecture, moving the latter into a specific section (e.g., "Proposed Architecture").

 

About the Conclusion section, it should be extended in order to summarize the entire process they followed, with the aim to offer a brief but complete summary of the work performed by them.

I also suggest to remove the subsection “6.1. Future work”, using a paragraph to provide these information.

 

The references do not appear quite updated (only two papers have been published in the last two years) and, in addition, accordingly to my previous observation on the “Introduction” section, the authors should include and discuss additional works related to the research scenario taken into account, in order to provide an overview to the readers, by including at least the following ones, which discuss about the “security”, “data exchange”, and “biometric” aspects:

(1) Li, X., Jiang, P., Chen, T., Luo, X., & Wen, Q. (2017). A survey on the security of blockchain systems. Future Generation Computer Systems.

(2) Huang, Z., Su, X., Zhang, Y., Shi, C., Zhang, H., & Xie, L. (2017, December). A decentralized solution for IoT data trusted exchange based-on blockchain. In 2017 3rd IEEE International Conference on Computer and Communications (ICCC) (pp. 1180-1184). IEEE.

(3) Saia, R., Carta, S., Recupero, D. R., & Fenu, G. (2019). Internet of entities (IoE): A blockchain-based distributed paradigm for data exchange between wireless-based devices. In 8th International Conference on Sensor Networks, SENSORNETS 2019 (pp. 77-84). SciTePress.

(4) Delgado-Mohatar, O., Fierrez, J., Tolosana, R., & Vera-Rodriguez, R. (2019, June). Blockchain and biometrics: A first look into opportunities and challenges. In International Congress on Blockchain and Applications (pp. 169-177). Springer, Cham.

(5) Garcia, P. (2018). Biometrics on the blockchain. Biometric Technology Today, 2018(5), 5-7.

 

In conclusion, apart from the minor problems previously highlighted, the most important weakness I found in the manuscript is the absence of a “clear” scientific contributions related to the proposed architecture.

This means that the authors must define in a clear way such contributions, with regard to the state-of-the-art solutions, reporting them in the Abstract, Introduction, and Conclusion sections.

This is a very important aspect, especially by considering that (as declared by the authors) thi work represents an extended version of a paper previously published by them, entitled “Consensus Algorithm for a Private Blockchain”: the authors need to well define the new contributions both respect to this previous paper and to the state-of-the-art solutions.

Author Response

Although the manuscript is well written, I suggest a careful re-reading of it in order to fix some minor typos (e.g., "behaivoral" instead of "behavioral" in Section 2.2, “conclusions, remarks and future work” instead of “conclusions, remarks, and future work” in Section 1, and so on).

Suggested minor typos have been corrected and a re-reading was carried out found other ones also corrected.

The overall structure of the manuscript does not follow the canonical structure of most literature articles, resulting somewhat unbalanced on the introductory part, with the result of reducing the contents readability.

I suggest to divide the "Introduction" section into two sections, "Introduction" and "Related Work", reserving the introductory section only for a brief overview of the domain taken into account, expanding each concept by using subsections of the "Related Work" section, instead of propose them as unhooked sections of the manuscript.

In any case, they should cite and discuss further papers focused on information very close or directly related to the research field taken into account by the authors, i.e., they should add more in-deep information and additional literature references.

For the same reasons I previously mentioned in relation to the introductory part, also the presentation of the proposed architecture results very confused.

The authors should avoid to mix literature information with information related to the proposed architecture, moving the latter into a specific section (e.g., "Proposed Architecture").

A "Related Work" section has been added including additional paper reviews, clarifying the highlights of the proposed architecture based on the works in literature.

About the Conclusion section, it should be extended in order to summarize the entire process they followed, with the aim to offer a brief but complete summary of the work performed by them.

I also suggest to remove the subsection “6.1. Future work”, using a paragraph to provide these information.

Some parts of the section has been rewritten and "Future work" subsection has been removed.

 

The references do not appear quite updated (only two papers have been published in the last two years) and, in addition, accordingly to my previous observation on the “Introduction” section, the authors should include and discuss additional works related to the research scenario taken into account, in order to provide an overview to the readers, by including at least the following ones, which discuss about the “security”, “data exchange”, and “biometric” aspects:

(1) Li, X., Jiang, P., Chen, T., Luo, X., & Wen, Q. (2017). A survey on the security of blockchain systems. Future Generation Computer Systems.

(2) Huang, Z., Su, X., Zhang, Y., Shi, C., Zhang, H., & Xie, L. (2017, December). A decentralized solution for IoT data trusted exchange based-on blockchain. In 2017 3rd IEEE International Conference on Computer and Communications (ICCC) (pp. 1180-1184). IEEE.

(3) Saia, R., Carta, S., Recupero, D. R., & Fenu, G. (2019). Internet of entities (IoE): A blockchain-based distributed paradigm for data exchange between wireless-based devices. In 8th International Conference on Sensor Networks, SENSORNETS 2019 (pp. 77-84). SciTePress.

(4) Delgado-Mohatar, O., Fierrez, J., Tolosana, R., & Vera-Rodriguez, R. (2019, June). Blockchain and biometrics: A first look into opportunities and challenges. In International Congress on Blockchain and Applications (pp. 169-177). Springer, Cham.

(5) Garcia, P. (2018). Biometrics on the blockchain. Biometric Technology Today, 2018(5), 5-7.

The suggested references have been added and additional ones too.

 

In conclusion, apart from the minor problems previously highlighted, the most important weakness I found in the manuscript is the absence of a “clear” scientific contributions related to the proposed architecture.

This means that the authors must define in a clear way such contributions, with regard to the state-of-the-art solutions, reporting them in the Abstract, Introduction, and Conclusion sections.

This is a very important aspect, especially by considering that (as declared by the authors) thi work represents an extended version of a paper previously published by them, entitled “Consensus Algorithm for a Private Blockchain”: the authors need to well define the new contributions both respect to this previous paper and to the state-of-the-art solutions.

 

Totally agree, hopefully with the new section "Related Work" this point will be clarified. In terms of the previous paper, the main contribution is highlighted in the introduction section which is the blockchain architecture combined with biometry technology, for this particular application which has not been reported yet to the best of our knowledge.  

Reviewer 2 Report

The author proposed a new architecture by integrating biometrics based authentication into a blockchain network, which is novel and interesting to the biometrics community as well as blockchain research field. The paper is well structured and described. In addition, I have two comments:

During the efficiency report, does the time consuming include the biometrics data comparison? If so, is there a time difference between fingerprint and iris?   I am not so clear of the procedures of biometrics comparison. If I understood correctly, the biometrics features are stored in the blockchain. During the comparison, the system will retrieve the reference feature from the blockchain to compare against the probe feature? Will the probe sample need to be stored somewhere in the blockchain as well?

Author Response

During the efficiency report, does the time consuming include the biometrics data comparison? If so, is there a time difference between fingerprint and iris?  

No, efficiency report does not consider biometrics data comparison.

I am not so clear of the procedures of biometrics comparison. If I understood correctly, the biometrics features are stored in the blockchain. During the comparison, the system will retrieve the reference feature from the blockchain to compare against the probe feature?

Biometry is just considered for user and ID authentication through the smart card, this feature is only accessed by the National Register Office before the person is doing a transaction. The block in BCT only considers information changes for example in the civil status or the tax information of the citizen.      

Will the probe sample need to be stored somewhere in the blockchain as well? 

Yes, in fact in the block diagram of a node in the network (Fig. 3) there is a database where all probe samples are stored. A comparison of the samples are made between the biometry of the bearer, the biometric information stored in the smart card and the one stored in the database.