4G/ Chaining Verfiable Credentials - Completeness Proofs for history and event squences in VCs

Chaining Verifiable Credentials

Tuesday 4G

Convener: Nathan George

Notes-taker(s):

Discussion notes, key understandings, outstanding questions, observations, and, if appropriate to this discussion: action items, next steps:

Starting point for the discussion: https://docs.google.com/presentation/d/1SgsdJkSPGeqQ2jxoH41v3RSSXIGJxCjdP3ptbygvq1w/edit?usp=sharing

Use cases discussed:

See use cases outlined in the slides +

Cited sources like in a news article

Link to the authority’s credential like this banking credential is linked to the proof that the bank is sanctioned or licensed.

Common pattern that I need to be able to prove the credential that joins them but not allow use of the pieces individually

Linking issued credentials to the evidence that issuing is based on seemed like a recurring pattern

Educational credentials where you prove you have taken all the classes for a degree?

When is it okay and not okay for linkages to cross issuer boundaries?

Easy answer was that these linkages cross these boundaries all the time.

GS1 example of things crossing different organizations because of country-member organizations

Really interesting observation that linked proofs or presentations of credentials are not the same thing as credentials with linking attributes in the credential itself.

Multisig or providence wrinkles:

You want three parties to agree you live at a particular address, but you don’t want to reuse the same proof from multiple authorities want three independent sources of proof.

Gathering multiple endorsers might also make a single proof more authoritative, so you would show that multiple members of the endorsement set approved.