Closed ChristopherA closed 3 years ago
+1 for a section mapping these common terms to how they fit into the VC data model terminology
+1 for a section. I concur with the observation mentioned on the call today that all three types of claims can be made within the framework of a verifiable claim, but we don't make that clear. In fact, sometimes we obfuscate it completely. A claim, as currently defined, is always an assertion by the issuer. Assertions could be about other claims and thereby provide evidence or evaluation/refutation.
It would be useful to show example claims that are about other claims, for example, providing evidence for a claim issued by someone else.
does ProofPurpose fully address this need?
This brings up https://github.com/w3c/vc-data-model/issues/118 where I describe how the three different types of claims can be presented using the existing spec.
@ChristopherA spoke about this and boiled it down to (1) a disparate set of terms used differently for similar ideas in different systems and (2) the need for examples to illustrate, in JSON-LD, how the current spec (with or without ProofPurpose) might achieve these three different types of claims.
My contention remains that ProofPurpose creates an added layer of ambiguous complexity and that all of the existing use cases can be implemented with the singular semantic that the proof in a VC means the controller of the proofing credentials uttered the statement embodied in the claims. Disputes, endorsements, evaluations, and evidence are best implemented as new credentials that are about other credentials and not as a bolted on property to the original credential. The signature on these commentary credentials means the signer utters the statement and the claims in the statement express the dispute or endorsement or whatever the comment is.
Chris made a point that some meta-data might be required by a given cryptographic suite. We ran out of time before we could unpack whether or not that makes a coherent case for varied meanings of ProofPurpose.
We'll work on examples.
@ChristopherA @jandrieu can you guys give an update on this?
@jandrieu ping again.
The VCWG discussed this on the call today. We are seeking feedback on concrete specification changes that the original issue submitters would like. We have not seen anything in two years on this issue. The VCWG is marking this issue as pending close and will close the issue in 30 days if we don't have engagement from the @ChristopherA and @jandrieu.
The issue was discussed in a meeting on 2021-06-14
No engagement since being marked pending close. 30-day window has elapsed. Closing.
Repeatedly when talking to various people using claims, largely from communities doing reputation systems, they make distinctions between 3 types of claims.
R3, a consortium of banks, at https://bitsonblocks.net/2017/05/17/a-gentle-introduction-to-self-sovereign-identity/ says:
This also come up with the Portable Reputation Toolkit from #RebootingWebOfTrust at https://github.com/WebOfTrustInfo/rebooting-the-web-of-trust-fall2016/blob/master/final-documents/reputation-toolkit.pdf