On 07/09/2022 00:22, Alan Karp wrote:
We discussed using VCs as capabilities a while back and concluded it was not a good idea.

Not everyone agreed this :-)

The main reason is that the use cases are quite different.  You don't know ahead of time who will need to verify a credential; you do with a capability.

This has not stopped people using driving licenses to buy alcohol at a variety of outlets, or enter night clubs or do a whole variety of things that were not envisaged by the issuing authority.


As a result, revocation is quite different for the two types.

Which is why VCs tell the verifier what the verification method is.


  Attenuated delegation is an important feature of capabilities, but its meaning is murky for credentials.

I agree that delegation of VCs has not been standardised yet


The argument for was the ability to use much of the same infrastructure for both.  At the time of that discussion, I said that using VCs as capabilities would be viable if there was a required type that could be either "credential" or "authorization" in order to keep the use cases distinct.

Depending upon your definition, every VC is an authorisation for something, otherwise there would be little point in having it.

Kind regards

David


I looked at the examples on github.  Either I'm missing something basic (a distinct possibility), or what's there is unworkable in the real world.

--------------
Alan Karp


On Tue, Sep 6, 2022 at 6:29 AM Orie Steele <orie@transmute.industries> wrote:
Related use case is NFTs that "allow you to participate in groups".

I've seen several versions of "authorization credentials", and we wrote a draft attempting to normalize them as related to capabilities.

https://github.com/transmute-industries/authorization-credentials

It's possible the next version of the vc data model could do more to define these "kinds" of credentials.

I suggest getting some framing together and maybe filing an issue?

OS



On Mon, Sep 5, 2022 at 5:44 AM Deventer, M.O. (Oskar) van <oskar.vandeventer@tno.nl> wrote:

Hi Steve,

 

Please note that my email is broader than the subject of your question. The main use case is the meta-credentials for trusted issuers.

 

As for your question on verifier authorisation: enforcement is automated.

  • Compare with the fingerprint data in a European passport. Only authorized devices can verify European-passport fingerprints. The chip on a European passport simply blocks if an unauthorized device request to verify my fingerprints, even if an 800-pound gorilla kindly asks me.
  • Compare with my Dutch bank account. I can spend my wealth freely. However, even if I am held at gunpoint, my ATM machine gives me at most 5000€ per day.

This is the yin and yang of “self-sovereign”. Europe considers it important to protect its free citizens against 800-pound gorillas. This is why European eIDAS regulation requires accreditation of verifiers of sensitive government-issued credentials. If your EUDI-wallet implementation does not satisfy this requirement, then Europe won’t accredit it, and your customers cannot use it for government-issued credentials.

 

Best regards,

 

Oskar

 

 

From: Steve Capell <steve.capell@gmail.com>
Sent: maandag 5 september 2022 12:18
To: Deventer, M.O. (Oskar) van <oskar.vandeventer@tno.nl>
Cc: W3C Credentials CG <public-credentials@w3.org>; Sporny, Manu <msporny@digitalbazaar.com>
Subject: Re: Funded Deployments of Verifiable Credentials - framework for meta-credentials

 

How do you authorise a verifier?

 

Surely the whole point of a VC is that the holder owns the data and is free to choose who to present it it to.  So the act of presentation is the authority to verify.  

 

Who controls who can verify in this eIDAS requirement? Even if there was a use case where verification is authorised by some party, how would it be enforced?  If an issuer gives me a credential then I can present it to anyone I choose.  If there’s information I don’t want to disclose then I redact it.  All this is beyond the control of the issuer 

 

Steven Capell

Mob: 0410 437854



On 5 Sep 2022, at 8:05 pm, Deventer, M.O. (Oskar) van <oskar.vandeventer@tno.nl> wrote:



Hi Manu, all,

 

Is there already ongoing work on “meta-credentials”, or should there be in W3C-CCG?

 

Verifiable credentials are always associated with some assurances.

  1. The issuer is trusted to issue this type of credential (https://github.com/hyperledger/aries-rfcs/tree/main/concepts/0289-toip-stack#discovery-and-verification-of-authoritative-issuers)
  2. The verifier is authorized to verify this type of credential (https://github.com/hyperledger/aries-rfcs/tree/main/concepts/0289-toip-stack#discovery-and-verification-of-authoritative-verifiers)

The former is the regular decision of a verifier to trust an issuer. The latter relates e.g. to the European eIDAS requirement that a verifier needs to be authorized to verify certain sensitive government-issued credentials.

 

Internet-reachable trust lists are the default solution to check whether an issuer or verifier is accredited to issue/verifier a certain type of credential, for example the EBSI Trusted Issuers Registry or other (Fraunhofer-TRAIN). However, internet-reachable trust lists have some major disadvantages.

  1. They don’t work in offline scenarios
  2. The “phone-home” interaction leaks information (=privacy)

 

An obvious alternative is meta-credentials, i.e. credentials about being authorized to issue/verify a certain type of credential. This alternative had already been highlighted in the aforementioned TOIP RFC 0289. There are many credential types, and potentially equally many of these meta-credentials. Nevertheless, it may be useful to develop a framework that enables automated verification of meta-credentials. At least it should be automatically verifiable whether a presented meta-credential is applicable to the type of credential that is requested or presented. Perhaps W3C could develop a generic solution for this?

 

Any thoughts?

 

Best regards,

 

Oskar

 

 

-----Original Message-----
From: Manu Sporny <
msporny@digitalbazaar.com>
Sent: zaterdag 27 augustus 2022 20:48
To: W3C Credentials CG <
public-credentials@w3.org>
Subject: Funded Deployments of Verifiable Credentials

 

Hi everyone (VCWG BCC'd),

 

I've been asked to do a presentation around funded deployments of Verifiable Credentials at multiple upcoming conferences (W3C TPAC, RWoT, etc.) and don't feel like I have a firm grasp of every publicly funded Verifiable Credential deployment happening around the world.

 

If you are funded to pilot or productionize a system that uses DIDs or Verifiable Credentials, and you are comfortable with talking about the program publicly, please add details to this slide deck:

 

https://docs.google.com/presentation/d/1JjfDbeXfE7aO7uYDNqNQ8ixVr9tXUQL7mhwudwxZN38/edit

 

I know I'm missing publicly announced projects from MATTR, Mesur.io, Mavennet, Transmute, and possibly Avast, ESSIF, the German government, and others. If you know of someone that's not on these lists, but is deploying VCs and DIDs, please send this request to them.

 

The first presentation is in two weeks, so please add your projects into the deck before then.

 

-- manu

 

--

Manu Sporny - https://www.linkedin.com/in/manusporny/

Founder/CEO - Digital Bazaar, Inc.

News: Digital Bazaar Announces New Case Studies (2021) https://www.digitalbazaar.com/

 

 

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