The goal of this article is to provide a definition of “verifiable credentials,” and a complete use case for a large university.

Here, you will find the introduction to a White Paper on the Dem-Attest-ULille Blockchain Project, led by the University of Lille, France’s largest public university with nearly 80,000 students, and pioneer and driver of the verifiable credential model. 

White Paper on the Dem-Attest-ULille Blockchain Project

Download the White Paper

The challenge of the Dem-Attest-ULille Project is to produce academic verifiable credentials (VCs) that are forgery-proof, bilingual and valid for life. Blockchain technology has been chosen for this purpose. 

The project is “user-oriented,” aiming to provide a better service to the holders of a verifiable credential, that is, students. It also aims to make the work of the issuer, in this case, the university, much more reliable and automated. 

Ultimately, much like a passport, or id document, it is intended to allow the university, other institutions, and potential employers to verify, for example, that claims of university credits and diplomas match the identity of the holder. Again, like a passport, it also mitigates the threat of a forgery of the diploma document.

What are verifiable credentials (VCs)?

A verifiable credential is no more and no less than a type of digital version of a title, diploma or certificate, issued by an authoritative issuer. So why is there so much buzz about this subject? The blockchain makes this new credential format “verifiable”, both at source and freely on the web, meaning that its integrity can be consulted without any risk of falsification or forgery.

In this context, A new standard World Wide Web Consortium (W3C) has recently been issued for this purpose, called, precisely, “Verifiable Credentials” (VCs)”. Likewise, the European Commission, which established the European Blockchain Service Infrastructure (EBSI), as a driver of this revolution, is continuing to set up identity and trust registries to allow the sharing of such credentials in this new VerifiableCredential format.


The roles and information flows forming the basis for the Verifiable Credentials specification. w3(.)org


The buzzwords describing a Verifiable Credential include:

  • Tamper-proof
  • Verifiable online, without having to consult a third party
  • Usable without any time limit, if not revoked by the controller or issuer
  • Usable on any verifier platform, using the VerifiableCredential (W3C) standard.

Why is there so much interest in Verifiable Credentials?

Why are we all so interested in this new type of credential that leverages blockchain technology? 

The Dem-Attest-ULille digital transformation project shows that blockchain, for a university, can be an extremely powerful tool in order to:

  • Provide an immediate service to students, offering them 100% digital, multilingual, tamper-proof diploma certificates, recognized by all, and worldwide,
  • Automate, improve the reliability, and the reduce the costs of producing and verifying academic credentials,
  • Strengthen confidence in institutions and the documents they issue, by providing employers or any other entity with tamper-proof documents immediately available on the web.

In the fall of 2021, more than 16,000 verifiable credentials were issued to the university’s graduates, demonstrating the success of the first phase of the model project, in this context.

Certainly, it is legitimate to ask:

Is it easy to use for everyone, and respectful of privacy and the environment?

This White Paper provides various testimonies and all of the documentation of the Dem-Attest-ULille project to answer these questions with a resounding, “Yes, yes, and yes!

The code developed by the University of Lille to integrate blockchain technology into its information system is available to all universities under open source license.

The Dem-Attest-ULille project Logo

Verifiable Credential Use Case : genesis of the Dem-Attest-ULille Verifiable Credential Project

The Dem-Attest-ULille project, launched in early 2021 by the University of Lille, is part of a threefold process involving:

  • The work initiated by the GTNum 8 Blockchain Education France (in French) Working Group, funded by the Ministry of National Education, Youth and Sports, Directorate of Digital Education,
  • The digitalization projects of the University of Lille’s registrar’s office,
  • The French governmental project fr.EBSI, funded by the European Blockchain Partnership and European Blockchain Service Infrastructure (EBSI). This project aims to deploy verifiable credentials according to the new W3C VerifiableCredential standard, based on the blockchain trust identity architecture deployed by the European Commission.

During its research, the Blockchain Education France Working Group has identified that the most internationally supported project involves work on verifiable credentials in order to reinvent the way:

  • Institutions issue learning outcomes (diplomas and other credentials),
  • Students, then citizens, retrieve them,
  • Employers and other training organizations verify them, throughout the lifecycle. 

Blockchain Education France, therefore, launched, during 2019, together with the company Blockchain Certified Data, publisher of the BCdiploma solution, a first pilot project to test these “blockchain verifiable credentials” for a small example population of students.  

At the University of Lille, the Certificate of Competence in Higher Education Languages (CLES) team, supported by the University of Lille’s registrar’s office, succeeded in issuing a first batch of 248 blockchain address type certificates over the course of a few months.

Feedback from students, recruiters and business teams is promising: they all sense a high value-added service, both in terms of the service provided and the potential for the digital transformation of administrative processes.

The project to extend the system to all of the issuer university’s diplomas is now taking shape, and was signed off by the Executive Committee in September 2020, and followed up by an innovative public contract between the customer and the company Blockchain Certified Data – BCdiploma in January 2021.

The University of Lille

The University of Lille announced the implementation of Digital Credentials for all graduates

On May 28, 2021, in its Press Release (in French), the University of Lille announced the implementation of a blockchain address solution of Digital Credentials for all graduates of the University, across subject areas:

“Starting in July, the University of Lille will deploy verifiable credentials of completion for all its graduates, using blockchain technology. 

From now on, the students of the University of Lille will receive an account link to claim a digital certificate “with probative value”, shortly after their graduation.

This credential, hosted on the university’s web servers and based on blockchain technology, will give employers or any entity all the information to verify the authenticity of the degree. 

The system will be generalized to 25,000 diplomas awarded annually by the university. 

While there have been occasional cases of experiments, mainly with small classes in large schools, the University of Lille is the first in France to deploy it on such a large scale.

Verifiable Credential Use Case: Dem-Attest-ULille Project Goals

The Dem-Attest-ULille project enables the implementation of a dematerialization process of the PDF “Certificate of completion of the diploma” document, currently produced using the university’s management software, APOGEE.

Here are the goals set out at the beginning of the project by Perrine de Coëtlogon, Director of the Dem-Attest-ULille Project, and Board Member of Open Education Global:

  • To provide the student with a “verifiable” type of digital diploma certificate, instead of a PDF, i.e. in a 100% digital tamper-proof format that does not age, and contains all the necessary proofs of authenticity and verifier signature of the controller issuer, in the shortest possible time,
  • To protect the privacy of the user and prevent the threat of diploma claims fraud,
  • To modernize the registrar’s office, in order to ensure:
    • a quality procedure for data production,
    • reduction in the time required for issuing and checking data,
    • translations of the credential and reference documents,
    • low cost (especially compared to paper),
    • the availability of the data does not age,
    • mitigation of the threat of forgeries,
  • To facilitate student mobility and access to employment,
  • To enhance the attractiveness of the “diploma”, which can be shared in a click, permanently available to the graduate,
  • To leverage the strengths of blockchain technology, or the “distributed ledger”:
    • document certificates remain in the blockchain, even if the technical partner is no longer active,
    • student user account signature and data is encrypted and distributed (in order to guarantees GDPR compliance),
  • To work with European registrar’s offices, starting with the Belgian ARES controller office (scholarships),
  • To work at the European and international level on the interoperability of these “verifiable credentials” (VCs).

Why choose blockchain technology

Why choose blockchain technology to issue Verifiable Credentials?

Here is the answer of Pierre Boulet, Vice-President of Digital Transformation at the University of Lille:

Why use blockchain technology for diploma digitalization projects at the University? 

Regarding the subject of the technology to be used, we started investigating and observing the market as far back as 2018. It turned out that blockchain technologies fully meet our needs, particularly in terms of security, protection against the threat of diploma forgeries, and age-less data availability.

The question of the verifiability of the validity of diplomas by anyone also arose. Decentralized technologies, in fact, make it easy to validate VerifiableCredential diplomas issued by a large number of license holder actors, in standard json formats. This is why the European Blockchain Partnership identified this one of the very first use cases to be implemented. Our diplomas are now set to be published on the EBSI European blockchain, which is almost in production, within the framework of the fr.EBSI project.

For more general considerations on the blockchain, see the chapter “A French and European vision of blockchain (in French)” of the White Paper “Blockchain technologies for the public sector,” published by the controller issuer, the University of Lille.

For more general considerations on the use of blockchain in the context of academic verifiable credentials, see the article “Understanding Digital Credentials”, by Luc Jarry-Lacombe, CEO and cofounder of BCdiploma.

What about the energy consumption of the blockchain?

Claims are often made against blockchain technology that it consumes an excessive amount of energy. However, such claims do not apply to all the various types of blockchain. Compliance with the highest energy footprint standards is one of the main prerequisites of the Dem-Attest-ULille Project, and the solution used for issuing verifiable credentials, namely BCdiploma, can work with several blockchains. So, the question was which one?

Pierre Boulet’s article, “Energy consumption of blockchain technologies (in French),” provides a comprehensive reflection on the subject:

The excessive energy consumption of some public blockchain technologies such as Bitcoin or Ethereum is not inevitable. This energy consumption, comparable to that of a small European country, comes from the consensus algorithm used: the proof-of-work. Since the appearance of Bitcoin in 2008, new consensus algorithms have appeared, offering a different compromise between security, decentralization and energy consumption. Ethereum’s planned migration to proof-of-stake – in 2022 – is set to be an important step towards less energy-intensive blockchain technologies.

For example, the University of Lille has chosen to deploy its degree certificates on the Avalanche blockchain, which operates with a “Proof of Stake” (PoS) protocol, and, thus, has an energy consumption 2,400 times lower than that of the Ethereum blockchain in its current configuration (Proof-of-Work, PoW).

Based on the latest work on the consumption of public PoS blockchains, we estimate that the carbon footprint of the issuing, on the blockchain, of a certificate by the license holder, for example, an entity such as the University of Lille, is about 0.025g of CO2, compared with an average of 4g for an email without any attachment.

Dem-Attest-ULille Verifiable Credentials project schedule

Dem-Attest-ULille Verifiable Credentials project schedule

Dem-Attest-ULille and the European fr.EBSI project

The University of Lille is leading the French project entitled fr.EBSI, which aims to issue diplomas in the European Blockchain Service Infrastructure (EBSI) blockchain ecosystem, with Blockchain Certified Data – BCdiploma as the technical operator.

To go further, you can consult the article “Verifiable credentials on the EBSI blockchain: everything you need to know about fr.EBSI project“.

The work presented above is a preliminary step to the large-scale deployment of the University of Lille’s Verifiable Credentials on the EBSI blockchain. More broadly, it provides the basis of a type of  generic solution for issuing credentials that respect the new European “VerifiableCredential” standard, by embedding decentralized diploma holder identifiers.

Within fr.EBSI, BCdiploma has deployed, for the customer, various interfaces to store the certificates produced on the EBSI blockchain, with the support of decentralized student entities and the University of Lille.

The first deliverable of the fr.EBSI project is an online identity verification service for the claim of credentials in the “ESSIF/EBSI Verifiable Presentation” json format :

The first deliverable of the fr.EBSI project is an online identity verification service

Try the Verifiable Credentials verification service by clicking here

This online verifier service checks whether a certificate complies with the expected json format and whether the signature is valid concerning the European Commission’s trust registries (EBSI blockchain), for all credential claims.

The second deliverable, produced by Blockchain Certified Data – BCdiploma for the customer and co-funded by NGI-ESSIF Lab and the i-Nov program, will be an open-source self-sovereign holder identity wallet, allowing students to keep, present and claim their obtained diplomas. This virtual student wallet will be deployed by the controller, the University of Lille, paving the way for many more projects focused on the identity of students.

virtual student wallet will be deployed by the controller

Want more details about the implementation of Verifiable Credentials at the University of Lille?

Download the White Paper by clicking here.

This gives access to information of the following:

  • The Dem-Attest-ULille Project Working Groups (WG)
  • Results of the “Process and quality” WG
  • Results of the “Models and data” WG
  • Results of the “Business interface within the E.N.T. of the University of Lille” WG
  • Architecture and data flow
  • Student satisfaction survey
  • About BCdiploma
  • Annexes

Enjoy your further reading!