Expand on Use Cases for Multi Party Credentials

[decentralgabe]

Related to:

• Representing Delegated Credentials in the VCDM vc-data-model#930
• Representing Mutli Subject Credentials in the VCDM vc-data-model#931
• Representing Multi Issuer Credentials in the VCDM vc-data-model#932

The second (multiple subjects) is all that's officially supported today.

I'd like to see some good multi-subject credentials have a place in the use case doc. Candidates:

• Marriage certificate (the example in the vc-data-model today)
• Birth certificate
• Any witness document

Delegated examples -- more risk here, may be worth avoiding. Possibly:

• Parent / child relationship, such as school registration -- issued to a parent who is a delegate of the child
• Relationship of medical necessity, such as a medical proxy -- issued to the medical proxy who is a delegate of the patient

Open to others!

[decentralgabe]

cc: @jandrieu @OR13 @msporny

[jandrieu]

PRs welcome

[decentralgabe]

On my list just haven't had time. Welcome help for PRs.

[iherman]

The issue was discussed in a meeting on 2023-02-07

• no resolutions were taken

View the transcript

1.3. Expand on Use Cases for Multi Party Credentials (issue vc-use-cases#126)

See github issue vc-use-cases#126.

Kristina Yasuda: PR needed.

Joe Andrieu: definitely.

[jandrieu]

@decentralgabe I don't know why I didn't ask this before, but we do have some coverage of this:
5.1 Citizenship by Parentage https://w3c.github.io/vc-use-cases/#citizenship-by-parentage

That includes both a marriage certificate and a birth certificate.

Is there more that you'd like to see?

We're open to improvements on that use case or if there's a wholly new situation, a PR would be welcome.

[decentralgabe]

I think having json examples would help

[jandrieu]

I think you're looking for details that could be/should be in an implementation guide.

In theory, the requirements precede the design. In practice, of course, we update the requirements to illustrate the reasons behind the design. However, we have attempted to draw a distinct line between defining the usage and defining the solution.

To wit, I'd be happy to add a bunch of JSON-LD examples, but the use case could, theoretically, also be satisfied with VC-JWT. So which examples should we use? Since we (the use case editors) see those as implementation details rather than requirements, I don't anticipate including JSON in the use case document.

[decentralgabe]

Something is needed (somewhere) to make the connection between the use case (abstract) and the implementation (concrete). If not here, maybe the impl guide is a better place, and we can close this issue.