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RE: Verifiable Credential Greeting Cards

From: Michael Herman (Parallelspace) <mwherman@parallelspace.net>
Date: Mon, 9 Dec 2019 18:17:29 +0000
To: Orie Steele <orie@transmute.industries>, Dan Burnett <daniel.burnett@consensys.net>
CC: "W3C Credentials CG (Public List)" <public-credentials@w3.org>
Message-ID: <MN2PR13MB2608DC19D065011F8145471AC3580@MN2PR13MB2608.namprd13.prod.outlook.com>
Orie, I think your example was quite valuable.  We need more real-world examples like this.

From: Orie Steele <orie@transmute.industries>
Sent: December 9, 2019 10:59 AM
To: Dan Burnett <daniel.burnett@consensys.net>
Cc: Michael Herman (Parallelspace) <mwherman@parallelspace.net>; W3C Credentials CG (Public List) <public-credentials@w3.org>
Subject: Re: Verifiable Credential Greeting Cards

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



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On Mon, Dec 9, 2019 at 9:37 AM Dan Burnett <daniel.burnett@consensys.net<mailto: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<mailto: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<mailto:daniel.burnett@consensys.net>>
Sent: December 5, 2019 10:21 AM
To: Orie Steele <orie@transmute.industries<mailto:orie@transmute.industries>>
Cc: Michael Herman (Parallelspace) <mwherman@parallelspace.net<mailto:mwherman@parallelspace.net>>; W3C Credentials CG (Public List) <public-credentials@w3.org<mailto:public-credentials@w3.org>>
Subject: Re: Verifiable Credential Greeting Cards



On Wed, Dec 4, 2019 at 5:30 PM Orie Steele <orie@transmute.industries<mailto: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"

  }

}




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On Tue, Dec 3, 2019 at 3:05 PM Michael Herman (Parallelspace) <mwherman@parallelspace.net<mailto: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?

[cid:image001.jpg@01D5AE82.39956050]

I think the corrected version of this greeting card should look like this…

[cid:image002.jpg@01D5AE82.39956050]

From: Orie Steele <orie@transmute.industries<mailto:orie@transmute.industries>>
Sent: December 2, 2019 8:16 AM
To: W3C Credentials CG (Public List) <public-credentials@w3.org<mailto: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<http://www.transmute.industries>

[https://drive.google.com/a/transmute.industries/uc?id=1hbftCJoB5KdeV_kzj4eeyS28V3zS9d9c&export=download]<https://www.transmute.industries>
[https://mailfoogae.appspot.com/t?sender=ab3JpZUB0cmFuc211dGUuaW5kdXN0cmllcw%3D%3D&type=zerocontent&guid=5925e95c-5236-49ce-adc2-b952d0e12654]ᐧ


--
ORIE STEELE
Chief Technical Officer
www.transmute.industries<http://www.transmute.industries>

[https://drive.google.com/a/transmute.industries/uc?id=1hbftCJoB5KdeV_kzj4eeyS28V3zS9d9c&export=download]<https://www.transmute.industries>


--
ORIE STEELE
Chief Technical Officer
www.transmute.industries<http://www.transmute.industries>

[https://drive.google.com/a/transmute.industries/uc?id=1hbftCJoB5KdeV_kzj4eeyS28V3zS9d9c&export=download]<https://www.transmute.industries>

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Received on Monday, 9 December 2019 18:17:37 UTC

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