W3C home > Mailing lists > Public > public-credentials@w3.org > December 2019

Re: Verifiable Credential Greeting Cards

From: Orie Steele <orie@transmute.industries>
Date: Mon, 9 Dec 2019 11:58:44 -0600
Message-ID: <CAN8C-_LtDdbKK_v4BZ2qj9R1qZE_kQ-OMZ9K4mTeuhJJ-BTMVA@mail.gmail.com>
To: Dan Burnett <daniel.burnett@consensys.net>
Cc: "Michael Herman (Parallelspace)" <mwherman@parallelspace.net>, "W3C Credentials CG (Public List)" <public-credentials@w3.org>
This example I have created is clearly terrible lol.

But I think that Dan Burnett's interpretation was my intention...

Once the card is delivered (by url), the VC could be presented by TO, and
the claim of TO having the greeting card object could be confirmed by some
poor greeting card verifier... both because the verifier trusts the issuer,
and because the subject has the credential which is a bearer token.

The main concern that I had was that the claim object "greetingCard" and
type property "HolidayCard" / "GreetingCard" were documented correctly, and
that there was an issuer who was "from" and a subject who was "to"... The
specifics of what a subject with a greeting card object claim means are
outside of my comprehension abilities...

It seems like I have accomplished these goals, despite the fact that the
example is clearly twisted and confusing :)

OS




ᐧ

On Mon, Dec 9, 2019 at 9:37 AM Dan Burnett <daniel.burnett@consensys.net>
wrote:

> Based on Orie's definition of FROM and TO (which I mistakenly capitalized
> as  'From' and 'To'), my statement is correct in terms of the intent his VC
> expresses.
>
>
> On Sat, Dec 7, 2019 at 4:20 PM Michael Herman (Parallelspace) <
> mwherman@parallelspace.net> wrote:
>
>> RE: As presented, the VC says that the From claims that the To has a
>> greetingCard property with certain values.
>>
>>
>>
>> Again, I think the interpretation should be that “there is an Issuer (who
>> happens to be the same entity as From) that is asserting that there is a
>> verifiable credential of type GreetingCard … with the following list of
>> Claims”.
>>
>>
>>
>>     "greetingCard": {
>>
>>       "type": "HolidayCard",
>>
>>       "image": "http://i.imgur.com/SxtVfyQ.jpg",
>>
>>       "message": "Happy Holidays!",
>>
>>       "from": "did:key:z6MkobeddxBBkCWdXZP7bAbTnjuJ9wmKPi8zzA1WwQtCCQRr",
>>
>>       "to": "did:example:123"
>>
>>     }
>>
>>
>>
>> I believe this is the most you can infer from reading the JSON (and not
>> extrapolating beyond what’s in the JSON).  There is nothing to imply “To
>> has a greetingCard property”?
>>
>>
>>
>> Michael
>>
>>
>>
>> *From:* Dan Burnett <daniel.burnett@consensys.net>
>> *Sent:* December 5, 2019 10:21 AM
>> *To:* Orie Steele <orie@transmute.industries>
>> *Cc:* Michael Herman (Parallelspace) <mwherman@parallelspace.net>; W3C
>> Credentials CG (Public List) <public-credentials@w3.org>
>> *Subject:* Re: Verifiable Credential Greeting Cards
>>
>>
>>
>>
>>
>>
>>
>> On Wed, Dec 4, 2019 at 5:30 PM Orie Steele <orie@transmute.industries>
>> wrote:
>>
>> Thanks for the feedback!
>>
>> I based the structure on:
>> https://www.w3.org/TR/vc-data-model/#example-7-specifying-multiple-subjects-in-a-verifiable-credential
>>
>> I thought of a greeting card as a VC with the Issuer being the FROM and
>> the subject being the TO.
>>
>>
>>
>> This is a fun example, but perhaps not best representative of the
>> intended use for VCs.  The VC model is that "an Issuer makes Claims about a
>> Subject, and includes a Proof (signature) that they did so".  So what are
>> you trying to prove? :)
>>
>>
>>
>> As presented, the VC says that the From claims that the To has a
>> greetingCard property with certain values.
>>
>>
>> After your comments, I'm not sure what I have done is correct.
>>
>> I have updated the demo to correct some missing fields and tested on
>> jsonld playground. Is this more what people were expecting?
>>
>>
>> OS
>>
>> {
>>
>>   "@context": [
>>
>>     "https://www.w3.org/2018/credentials/v1",
>>
>>     "https://transmute-industries.github.io/vc-greeting-card/context/vc-greeting-card-v0.0.jsonld"
>>
>>   ],
>>
>>   "id": "https://example.com/credentials/1872",
>>
>>   "type": [
>>
>>     "VerifiableCredential",
>>
>>     "GreetingCard"
>>
>>   ],
>>
>>   "issuer": "did:key:z6MkobeddxBBkCWdXZP7bAbTnjuJ9wmKPi8zzA1WwQtCCQRr",
>>
>>   "issuanceDate": "2019-12-04T22:20:39.285Z",
>>
>>   "credentialSubject": {
>>
>>     "id": "did:example:123",
>>
>>     "greetingCard": {
>>
>>       "type": "HolidayCard",
>>
>>       "image": "http://i.imgur.com/SxtVfyQ.jpg",
>>
>>       "message": "Happy Holidays!",
>>
>>       "from": "did:key:z6MkobeddxBBkCWdXZP7bAbTnjuJ9wmKPi8zzA1WwQtCCQRr",
>>
>>       "to": "did:example:123"
>>
>>     }
>>
>>   },
>>
>>   "proof": {
>>
>>     "type": "Ed25519Signature2018",
>>
>>     "created": "2019-12-04T22:20:39Z",
>>
>>     "jws": "eyJhbGciOiJFZERTQSIsImI2NCI6ZmFsc2UsImNyaXQiOlsiYjY0Il19..TO7wGkMcM-Ey2h2I2GMRsOAQ8r9xPL7mDEkPefuYmUy32lYhRuS0AiNjcIpYYkWil8RvITmnpb2syqDgpPgsAg",
>>
>>     "proofPurpose": "assertionMethod"
>>
>>   }
>>
>> }
>>
>>
>>
>>
>>
>> ᐧ
>>
>>
>>
>> On Tue, Dec 3, 2019 at 3:05 PM Michael Herman (Parallelspace) <
>> mwherman@parallelspace.net> wrote:
>>
>> Orie, I have a follow-up question regarding the value of the *id*
>> attribute in the *credentialSubject* (line 14).
>>
>>
>>
>> In the current implementation, the value of the *credentialSubject*’s
>> *id* attribute is the value of the *to* attribute, the subject/entity
>> the greeting card is addressed to.
>>
>>
>>
>> Is this correct?  …this is a credential about a specific *greeting card*
>> – that is, the greeting card is the subject of this credential, n’est pas?
>>
>>
>>
>>
>>
>> I think the corrected version of this greeting card should look like this…
>>
>>
>>
>>
>>
>> *From:* Orie Steele <orie@transmute.industries>
>> *Sent:* December 2, 2019 8:16 AM
>> *To:* W3C Credentials CG (Public List) <public-credentials@w3.org>
>> *Subject:* Verifiable Credential Greeting Cards
>>
>>
>>
>> I've been working on some supporting documentation regarding JSON-LD
>> Contexts, extending them and hosting your own, as well as interop with
>> did:key.
>>
>> If you are interested in creating custom credential formats for new use
>> cases, this demo may be of use to you.
>>
>> https://transmute-industries.github.io/vc-greeting-card/
>>
>> Here is a VC Greeting card for this list, happy holidays:
>> https://transmute-industries.github.io/vc-greeting-card/?vcgc=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
>>
>> OS
>>
>>
>>
>> --
>>
>> *ORIE STEELE*
>>
>> Chief Technical Officer
>>
>> www.transmute.industries
>>
>>
>>
>> <https://www.transmute.industries>
>>
>> ᐧ
>>
>>
>>
>>
>> --
>>
>> *ORIE STEELE*
>>
>> Chief Technical Officer
>>
>> www.transmute.industries
>>
>>
>>
>> <https://www.transmute.industries>
>>
>>

-- 
*ORIE STEELE*
Chief Technical Officer
www.transmute.industries

<https://www.transmute.industries>

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Received on Monday, 9 December 2019 17:59:00 UTC

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