Re: DIF VC-JWTs look like Linked Data Proof Verifiable Credentials

Btw, is the DanubeTech implementation failing? This may be blocking the
ability to submit test reports to that suite

On Tue, Mar 1, 2022 at 1:42 PM Kim Hamilton <kimdhamilton@gmail.com> wrote:

> That's right; I do think did-jwt-vc can be made conformant, but there are
> some repo/work item ownership issues to sort out. Perhaps we (Centre) can
> help with that after we figure out who else is interested in actively
> contributing to that repo going forward.
>
> On Mon, Feb 28, 2022 at 10:38 AM Charles E. Lehner <
> charles.lehner@spruceid.com> wrote:
>
>> Hi,
>>
>> JwtProof2020 is described as "for internal use" in DIF's did-jwt-vc
>> library:
>> https://github.com/decentralized-identity/did-jwt-vc#notes-on-verification-and-proof-properties
>> > The JwtProof2020 is a synthetic proof type, usable for differentiating
>> credentials by type. It is not a registered W3C VC Data Model algorithm and
>> should not be treated as such.
>>
>> I saw a VC with this format in a demo recently, which I think suggests it
>> may be leaking into non-internal use.
>>
>> I don't see a specification for it, or an IRI for the proof type. The
>> implementation in DIF's did-jwt-vc repository produces it here:
>>
>> https://github.com/decentralized-identity/did-jwt-vc/blob/94fdd6f280579cc2b0b9a0125855ee13916b6b52/src/converters.ts#L173-L187
>>
>> https://github.com/decentralized-identity/did-jwt-vc/blob/94fdd6f280579cc2b0b9a0125855ee13916b6b52/src/converters.ts#L417-L431
>> There does not seem to be a verifier implemented there, only the
>> conversion from JWT-VC into VC with proof object of this type (with
>> conversion of some properties).
>>
>> I think JwtProof2020 looks useful as way to convert a VC-JWT into an
>> equivalent VC-with-proof-object. Maybe this could enable using VC-JWTs in
>> APIs that require a VC-with-proof-object; then APIs would not need
>> polymorphism like was proposed in
>> https://github.com/w3c-ccg/vc-api/pull/208 .
>> Maybe this format could encapsulate the conversion process between JOSE
>> claims and VC fields such as is specified in the VC Data Model:
>> https://www.w3.org/TR/vc-data-model/#jwt-encoding
>> But it would need to be determined how to verify this proof type,
>> including ensuring that the properties outside the JWT correspond to the
>> JWT payload.
>>
>> There is some more discussion here:
>>   https://github.com/centrehq/verite/issues/373
>>
>> Regards,
>> Charles Lehner
>>
>> On Thu, 24 Feb 2022 08:08:19 -0600
>> Orie Steele <orie@transmute.industries> wrote:
>>
>> > Hey Folks,
>> >
>> > As we gear up for VCDM2.0 there are a number of VC-JWT
>> > implementations that we are tracking and attempting to show
>> > interoperability across.
>> >
>> > One of the oldest VC-JWT implementations is hosted at DIF, but it
>> > produces VC-JWTs that are not compact JWTs ... they look more like
>> > Linked Data Proof VCs.
>> >
>> > As far as I know, no other VC-JWT implementation supports this
>> > format, aka "JwtProof2020".
>> >
>> > Here is a link to an issue with an example:
>> > https://github.com/centrehq/verite/issues/373#issuecomment-1049888568
>> >
>> > If you have a few minutes, I would love some review of what the DIF
>> > implementation is doing, and how we can either push it all the way
>> > into the LD Proof camp, or all the way into the VC-JWT camp.
>> >
>> > Regards,
>> >
>> > OS
>> >
>>
>>