Design, Implementation and Practical Energy-Efficiency Evaluation of a Blockchain Based Academic Credential Verification System for Low-Power Nodes

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

A review of the paper entitled "Design, Implementation, and Practical Evaluation of the Energy Efficiency of a Blockchain-Based Academic Credential Verification System for Low-Power Nodes" was conducted. We acknowledge the author's trust in carrying out the described task, and the general observations and suggestions drawn from the article are presented below.

In summary, the article constitutes a substantial and relevant contribution to the field. The topic—the use of blockchain for academic credential verification—is contemporary, relevant, and of growing interest in both academic and industrial contexts. The technical approach is solidly grounded, and the inclusion of a practical evaluation on low-power devices, an aspect rarely examined in such detail, is appreciated. The comparison between proof-of-work (PoW) and proof-of-authority (PoA) from an energy and performance perspective is particularly valuable and can be of great use to researchers and developers seeking to move toward sustainable solutions.

However, certain areas have been identified that could be improved to increase the impact and clarity of the work. First, a need for further analysis of smart contract security has been observed. The security analysis is somewhat limited. It would be advisable to include, even briefly, a formal assessment or the use of tools such as Slither, Mythril, or similar, which are standard in smart contract audits.

Regarding privacy and regulatory compliance, it is essential to address the guarantee of privacy regulations, such as the GDPR, especially considering the inherent public accessibility of IPFS, given the off-chain data storage by OrbitDB and IPFS.

Regarding scalability and governance in PoA, it is pertinent to mention that the article assumes a relatively small institutional environment. It would be beneficial to explore how this model would adapt to networks comprising multiple actors, such as universities, agencies, and companies. Likewise, a thorough analysis of the risks associated with centralization and potential collusion attacks in the context of PoA is considered highly relevant, as such an assessment could provide valuable information for continuous system improvement.

Finally, further elaboration is suggested in the usability and user experience (UX) section. Although the technical design is robust, it would be beneficial to include an assessment of the interface's suitability for non-technical users, such as students or teachers without a computer science background, even if only exploratory.

Finally, the article would benefit from a thorough analysis of interoperability standards. Since the lack of standardization in credential recognition has been identified as a barrier, it would be useful to briefly mention initiatives such as EBSI, Verifiable Credentials, or DIDs (Decentralized Identifiers), and reflect on how this solution aligns with or could be integrated with them.

Finally, it is pertinent to acknowledge the authoring team for the decision to share the code as open source. This practice promotes reproducibility and accelerates progress within the scientific and technical community.

I reiterate my gratitude for the opportunity to contribute to the editorial process and express my willingness to provide additional clarifications if needed.

Author Response

Please find attached our detailed responses to the comments. In order to ease the labor of the reviewers, in the new manuscript we have colored in red the differences with the previous version of the article.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The present article entitled “Design, Implementation and Practical Energy-Efficiency

Evaluation of a Blockchain Based Academic Credential Verification System for Low-Power Nodes” by Gabriel Fernandez-Blanco et. al. discusses the design and implementation of a blockchain-based system for verifying academic credentials, focusing on energy efficiency and the use of decentralized applications. Even the  subject of the paper is very important the text is not well organized since is a mix for a review article, technical report and a research paper. However  it could be accepted taking into account the following points:

1. Authors have to answer the following questions:
   1. How is the traceability and immutability of academic records ensured on the blockchain?
   2. How can the energy efficiency of DApps be improved with newer technologies (e.g., Ethereum 2.0, PoS)? Are the proposed models applicable now?
2. The authors have to explain their contribution to this specific work and not to explain everything that takes place in generally. First step is to give the problem and the second one to show their contribution by presenting and explain their experimental results.
3. Has an energy consumption calculation been performed for scenarios where a realistic number of students worldwide request graduation certificates on a daily basis?
4. Are the experimental results that presented in (figures 12,13 etc) reproducible, and if not, what is the margin of error?

Comments on the Quality of English Language

The present article entitled “Design, Implementation and Practical Energy-Efficiency

Evaluation of a Blockchain Based Academic Credential Verification System for Low-Power Nodes” by Gabriel Fernandez-Blanco et. al. discusses the design and implementation of a blockchain-based system for verifying academic credentials, focusing on energy efficiency and the use of decentralized applications. Even the  subject of the paper is very important the text is not well organized since is a mix for a review article, technical report and a research paper. However  it could be accepted taking into account the following points:

1. Authors have to answer the following questions:
   1. How is the traceability and immutability of academic records ensured on the blockchain?
   2. How can the energy efficiency of DApps be improved with newer technologies (e.g., Ethereum 2.0, PoS)? Are the proposed models applicable now?
2. The authors have to explain their contribution to this specific work and not to explain everything that takes place in generally. First step is to give the problem and the second one to show their contribution by presenting and explain their experimental results.
3. Has an energy consumption calculation been performed for scenarios where a realistic number of students worldwide request graduation certificates on a daily basis?
4. Are the experimental results that presented in (figures 12,13 etc) reproducible, and if not, what is the margin of error?

Author Response

Please find attached our detailed responses to the comments. In order to ease the labor of the reviewers, in the new manuscript we have colored in red the differences with the previous version of the article.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

How would the system scale to an international consortium of universities with different regulatory frameworks?

What specific identity recovery mechanisms are proposed in the event of private key loss?

Could the system be enhanced with decentralized reputation or academic scoring, beyond binary verification?

How would the revocation of certificates already issued on the blockchain be handled without violating immutability?

How feasible is it to implement multi-party contracts for collaborative validation (e.g., professor + program director)?

Author Response

Please find attached our detailed responses to the comments. In order to ease the labor of the reviewers, in the new manuscript we have colored in red the differences with the previous version of the article.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Now, the authors of the paper entitled “Evaluation of a Blockchain Based Academic Credential Verification System for Low-Power Nodes” have adopted most of the remarks and the paper is acceptable in the present form.

Author Response

Please find attached our detailed responses to the comments.  

Author Response File: Author Response.pdf