Footnote

1. A Learner Earns a Degree

This is the most classic case of using VCs but also the most coarse-grained. A learner might receive a degree—for example, a B.Sc.—from an accredited institution. The institution issues the VC and registers it to the ledger, and the learner adds it to a wallet. 

Although VCs are of course machine readable, making sense of them in an automated way requires a data model; efforts toward such a data model are under way for degrees or the nontraditional concept of badges. In addition to the VC, the learner might receive a decorative certificate as a PDF, which can be printed, framed, and put on the wall. This PDF would go into the data pod, and a hash of the PDF might go into the ledger to prove its authenticity. Within the federation, though, the machine-readable VC will be used.

2. A Learner Earns Course Credit

On a more fine-grained level, a user might receive credit for a course. Again, the institution would issue a VC for the course. Course equivalencies are a constant challenge—although different institutions offer large numbers of basically equivalent courses (think Calculus I), defining eligibility for transfer credit is a complex task because courses not only have different titles but also different flavors. In the United States, handling transfer credit is done partly by crowdsourcing among institutional registrars,Footnote while in Europe, the European Credit Transfer and Accumulation System (ECTS) is essential. Crowdsourcing is a scalable mechanism for this: if the registrar at one institution in a federation of mutually trusted partners confirms a particular course equivalency (i.e., equivalency between classes of VCs), this would become part of the „shared knowledge“ of the federation. For the purpose of issuing automatically transferable course VCs, the federation needs to make use of these or similar structures.

3. A Learner Needs to Have a Foreign Degree Acknowledged

An ecosystem like this cannot be implemented from one day to the next. Historical or „foreign“ (in the sense of „created outside the ecosystem“) credentials need to be taken in as users are onboarded. In the analog world, certain national entities already assist in this process, and such services could evaluate paper-based documents and issue corresponding VCs. Alternatively or in a complementary manner, registrars could acknowledge these degrees as transfer degrees and issue corresponding VCs.

4. A Learner Explores a Possible Study Program

A learner might consider a study program at an educational service provider. The provider might make available adaptive recommender systems, but the user might choose not to connect using asserted identity, opting instead to anonymously explore. The recommendation system might ask for information about the learner’s educational history, where the quality and usefulness of the recommendations will likely depend on how much the learner chooses to reveal. For example, a master’s program will likely expect the learner to have earned the equivalent of a bachelor’s degree at some point in time, but the user could choose to reveal only that such a credential exists without disclosing the major or a GPA. At this point, the applicant may also decide to provide proof of previous coursework (see scenario 2) to see which credits may be acknowledged as transfer credit.

5. A Learner Applies for a Study Program and Gets Admitted

A learner decides to apply for a study program at an educational service provider but chooses to not reveal their asserted identity. Such a decision not to disclose identity might actually be in the best interest of the provider, given that the preservation of anonymity can help avoid accusations of acceptance bias due to gender or apparent ethnic background of the applicant. However, the applicant needs to reveal more information than in scenario 4, such as majors and grades, which become relevant for the application process. Also, VCs for transfer credit need to be provided.Footnote

These credentials might be presented years after they are issued. The issuer of these credentials does not need to exist anymore to verify these credentials, which is a significant improvement over the analog scenario in case an institution closes or somehow loses its records.

For programs in the design, musical, or fine-arts sector, the applicant at this point might also reveal sections of their data pod, which could contain portfolio artifacts such as audition recordings, scanned artwork, or digital media pieces. There is also the problem of confidential letters of recommendation (scenario 14).

Upon acceptance, the student would have to disclose his or her identity, see scenario 12. In exchange, they would get a VC proving affiliation with the university (the equivalent of a „Student-ID“). This could also be used to gain entrance to buildings (scenario 13) and get discounts (scenario 15).

6. A Learner Applies for Graduation

When learners apply for graduation, they will turn in all relevant course credits (scenario 2) to the registrar’s office for evaluation. A notable difference to the current method is that with pure SSI, the user stores credits, similar to the German concept of „Scheine,“ which actually used to be pieces of paper.

Realistically, though, the home institution would keep duplicate records, which may be desirable for a number of reasons: the institution could contact students if they fall behind in their studies or are about to miss deadlines; the concept of „failing an exam for good“ (i.e., not being able to repeat it, no more retries allowed) cannot be mapped to pure SSI; and internal records may be important if credentials need to be revoked (scenario 11).

An open question is which records are authoritative in case of disputes, but this is true today: if a student holds a valid (non-fraudulent) paper degree certificate, but the university for whatever reason lost the record of that degree, it may be up to a court to decide who „wins.“ Another open question is whether employers or potential clients should be able to verify a degree with a university without the subject knowing – asking somebody to prove that they really have a doctorate might destroy business relationships, but checking behind their backs … some etiquette might have to develop around SSI, where zero-knowledge-proofs are delivered as a matter of course alongside CVs when initiating client-customer relationships, so embarrassing questions or sneaky background checks become unnecessary.

7. A Learner Needs to Use an External Service as Part of Coursework

Particularly due to the COVID-19 pandemic, it became apparent that a monolithic local learning management system (LMS) does not adequately serve the needs of all instructors and learners. Instead, more and more instructors desire to use the plethora of cloud services that are available, such as Piazza, Miro, online homework systems, Slack, Google Docs, MS Teams, Quizlet, and Kahoot, to name but a few. Using such services raises considerable privacy concerns, and learners complain about having too many usernames and passwords. In addition, performance information usually does not flow back into the campus LMS.

This use case for SSI is probably the least „classic,“ in that it uses fine-grained VCs as a means to achieve privacy-preserving systems interoperability between decentralized cloud services and learning resources. In this scenario, the learner connects to the service using a DID. As the learner works, artifacts may be stored in the data pod, and after completion of tasks, the service issues a VC. The learner subsequently submits the VC to the local LMS to receive credit for the activity.

8. A Learner Participates a Study Abroad or Mobility Program

The learner may want to spent a semester at another institution. The learner might confirm his or her eligibility by providing proof of study progress to their local mobility office. Exploring and applying to the hosting university would be handled essentially the same way as in scenarios 4 and 5, respectively. Upon return, this process requires no additional effort, because the hosting institution would have issued course credit (scenario 2), which the learner would turn in when applying for graduation (scenario 6).

9. A User Applies for a Job

A company’s HR portal allows applicants to connect and make available VCs and portfolio files, similar to the process of applying for a study program (scenario 5).

10. A Company Requires Regular Training from Its Employees

A company (or regulatory body, professional organization or laboratory facility) requires annual compliance training from its employees. The employees have a choice of providers. After successfully completing the training with one of these providers, the provider issues a VC with an expiration of one year. The employee then presents this VC to the company.

11. Academic Fraud Is Discovered

Years after a person completed an M.Sc. with a university, it is detected that the thesis was plagiarized. After careful investigation and deliberation, the institution decides to revoke the degree. At this point, a ledger entry is made to revoke the VC associated with the degree. If the person subsequently attempts to present the VC to another institution or a potential employer, the VC will come back invalid. All transactions are cryptographically recorded and documented in case of legal disputes.

12. The Learner Needs to Assert His or Her Identity

The learner’s identity would be asserted using a VC as the equivalent of passports or ID-cards. In many cases, this would be government-issued (by some government, domestic or globally), proofing that one or more of the learner’s DIDs are associated with their identity. Students might have more than one citizenship, but would need to decide on at least one from a trusted government (the educational ecosystem’s governance would need to trust the SSI-ecosystem of the respective government). Alternative, the educational ecosystem could decide to accept VCs from registrar’s offices of an institution within their own ecosystem or other educational ecosystems, which would have checked identities in a traditional way and then issued a VC.

13. A University Enforces Building or Laboratory Access Control

VCs can be used for access control not only to IT systems, but also buildings or laboratories. Access control could depend on institutional affiliations (scenario 5) and possibly passed safety and compliance training (scenario 10).

14. Confidential Letter of Recommendation

Many degree programs require letters of recommendation written by university faculty. While by default students have a right to see these letters, they are taken more seriously if students waive this right. These letters could be stored in a student’s data pod, but pose a challenge for SSI: the student would be the subject and the holder of these letters, and they could be secured by a ledger entry, but the student should not be able to see the content of these letters – they would need to be able to present them, and the recipient should be able to verify them, but the contents are hidden from the subject and holder.

15. Students Get Discounts

Students need to be able to present their „Student ID“ (VC) to vendors, museums, public transportation, etc., to get student discounts.