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Re: Identifiers in Verifiable Credentials

From: steve capell <steve.capell@gmail.com>
Date: Wed, 9 Jun 2021 13:49:50 +1000
Message-ID: <CAEMprtJRrneSKV_Fi+biKapODM9_WOT6RMuoMQ-fwvDuZq8jeQ@mail.gmail.com>
To: Adrian Gropper <agropper@healthurl.com>
Cc: Manu Sporny <msporny@digitalbazaar.com>, W3C Credentials Community Group <public-credentials@w3.org>
Hi Adrian,

We've got a few goals with all this:

   - really short term (ie doing it now) - *"simple VCs" *to replace
   cross-border paper documents with verifiable credentials for improved
   integrity & efficiency.  Specific examples
      - preferential and non-preferential certificates of origin
      - Phytosanitary (food health/quality) certificates
   - medium term (experimenting with it now) - *"participation in the trust
   economy"* to prove a model where regulators (eg department of
   agriculture) can leverage industry assurance schemes as  in order to reduce
   burden on trusted parties and to improve detection of non-compliance.
   Specific examples:
      - Developing a mutual recognition framework and supporting harmonised
      vocabulary of claims from multiple food safety assurance schemes (bit of
      machine learning in this) so that producers / exporters need only prove a
      thing once. eg a typical farmer in AU has to comply with
      https://www.foodauthority.nsw.gov.au/,   https://saiplatform.org/,
      https://harpsonline.com.au/,
      https://micor.agriculture.gov.au/Pages/default.aspx and more - if a
      farmer has verifiable compliance claims from a trusted industry assurance
      framework then the regulator will accept them
      - Leveraging high integrity digital trade documents to reverse the
      regulatory compliance paradigm from (for example) "read that
huge stack of
      rules and figure out your duty payment" to "give us your
commercial invoice
      and we'll tell you what duty to pay".
   - longer term (but not too far away) - *supply chain transparency and
   traceability* across/between multiple trust networks.  There's lots of
   "use my blockchain magic platform to get traceability in your supply chain"
   type products out there now.  All have a specific geography and industry
   niche.  None will become the "facebook of trade" (thankfully!) and, in most
   cases, even one consignment touches multiple platforms.  So genuine
   transparency and traceability needs cross-platform linked claims. That's
   where VCs excel. The interesting challenge here is is how to do that
   without explicit authority delegations between parties that dont know each
   other but rather do it via a (kind of) off-chain NFT that accompanies the
   goods in any leg of a value chain.  We're doing some fun experiments with
   that now.

kind regards,

On Wed, 9 Jun 2021 at 12:40, Adrian Gropper <agropper@healthurl.com> wrote:

> What kind of NFTs are you building?
>
> - Adrian
>
> On Tue, Jun 8, 2021 at 6:30 PM Steve Capell <steve.capell@gmail.com>
> wrote:
>
>> Isn’t it true that pretty much every VC that is about a “thing” (eg an
>> invoice about a shipment , a bill of lading about a consignment, an origin
>> certificate about a product , etc) are bearer VCs because the verifier only
>> cares about proof of issuer ID.  the ID of the thing (subject) isn’t
>> something that the thing has to (or is able to) prove.  It’s just an
>> assertion by the issuer
>>
>> These “esoteric” cases represent 99% of my use cases and volumes
>>
>> Steven Capell
>> Mob: 0410 437854
>>
>> > On 9 Jun 2021, at 6:02 am, Manu Sporny <msporny@digitalbazaar.com>
>> wrote:
>> >
>> > On 6/6/21 5:57 PM, Kerri Lemoie wrote:
>> >> I’m not clear on the uses for the optional id in the vc assertion. It
>> >> would be helpful to learn about some examples or suggested uses.
>> >
>> > I saw answers for why you wouldn't want to use an `id` in the VC
>> assertion. I
>> > didn't see many examples of why you would want to use `id`. Here are
>> two:
>> >
>> > * You have a single-use bearer token (movie ticket, age
>> >  token) that you want to determine if it's been used
>> >  before or not. Identifiers like this are useful for that
>> >  use case:
>> >
>> >  urn:uuid:ddf810cc-c891-11eb-9fd3-67046f0b67f0
>> >
>> >  These sorts of identifiers also compress well when
>> >  using CBOR-LD (to 16 bytes) and help when encoding
>> >  to QR Codes.
>> >
>> > * You have a public Verifiable Credential where you
>> >  might want to publish other information, such as
>> >  an HTML representation of the VC. An Open Badge
>> >  URL might be a good use here.
>> >
>> > There are other uses, but they tend to be fairly use case specific and
>> thus,
>> > esoteric.
>> >
>> > -- manu
>> >
>> > --
>> > Manu Sporny - https://www.linkedin.com/in/manusporny/
>> > Founder/CEO - Digital Bazaar, Inc.
>> > blog: Veres One Decentralized Identifier Blockchain Launches
>> > https://tinyurl.com/veres-one-launches
>> >
>> >
>>
>>

-- 
Steve Capell
Received on Wednesday, 9 June 2021 03:51:37 UTC

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