Re: Verifiable Credentials use case questions

Hi all,

Thanks for your time and the provided replies.

Following the message from Eric above, we would like to understand in a
more technical or detailed way, the transfer capability that appears in the
aforementioned standard. Although a specification is not defined there, we
guessed that "transfer" could potentially mean that person A could
send/move a VC from his wallet to person B, making B the new owner of that
VC.

If our guess is right, this would be a very powerful feature to be used in
our use case as no need for a 3rd issuer would be required and an exchange
of a VC peer-to-peer could be used. However, we might be wrong on how we
think that works. Is there any documentation we could use to study how this
transfer capability works?

In contrast to NFT, VCs are linked with an issuer and a subject (name and
surname) which makes it easier when verifying the owner (as a human being)
of a unique item.

Thanks in advance.

Best regards,
Brian

El lun, 27 sept 2021 a las 14:31, Adrian Gropper (<agropper@healthurl.com>)
escribió:

> Hi Leah,
>
> I discuss some of this in
> https://cyber.harvard.edu/lists/arc/projectvrm/2021-09/msg00101.html
>
> Online identity matching equivalent to in-person biometric matching is a
> difficult problem tied to reputation. NFTs and VCs are not, in themselves,
> a solution to the extent that they do not introduce live human matching
> like a notary into the transaction.
>
> - Adrian
>
> On Mon, Sep 27, 2021 at 4:55 AM Leah Houston, MD <leah@hpec.io> wrote:
>
>>
>> Hi there, not sure if you got any valuable responses to this question,
>> and I might not be the best person to answer, i’m working on a
>> credentialing and identity solution for doctors… And whenever people start
>> talking about NFT’s I say… “Well yeah… A doctors credential is an NFNTT -
>> Nonfungible and nontransferable token:)”
>>
>>
>>
>> On Mon, Sep 27, 2021 at 4:36 AM Eric <e.garcia.ribera@gmail.com> wrote:
>>
>>> Hello all,
>>>
>>> I would like to quickly explain the use case we are working on at the
>>> moment and ask a question we'll need to solve in order to start pushing the
>>> use case forward. Appreciate your time in advance.
>>>
>>> Our main goal was to use NFTs as a proof of ownership for physical
>>> objects. The real world object would be linked to NFTs, and the owners of
>>> those could sell or buy other NFTs in demand. Once we started developing
>>> the idea and a PoC, we quickly identified an issue with NFTs that could
>>> stop our progress. The issue was that the owner of a physical object
>>> (linked to an NFT) had no straightforward way of proving him/herself as the
>>> real owner.
>>> Imagine the scenario where person A just wants to prove person B is the
>>> owner of an NFT. Since the NFT owner is identified by an address, the owner
>>> would need to prove ownership by opening the wallet and show that the NFT
>>> owner's address it's him/hers. Doing this in the real world when you are in
>>> front of the verifier (person that wants to check you own a specific NFT)
>>> can be done by showing your wallet owns that address. However, doing this
>>> online, doesn't seem to be straightforward. Maybe I'm mistaken and there is
>>> an easy way of proving ownership. If this exists, I would really appreciate
>>> an explanation on that since I'm not aware of any.
>>>
>>> At this point, we discovered DIDs and Verifiable Credentials. When we
>>> read the standards we came to the conclusion that VCs could be used as
>>> NFTs, since these provide similar features (a DID could identify the
>>> creator of an object, and another DID, signed by the creator, could
>>> identify the created object. Later on, the creator could issue a VC to the
>>> first buyer, giving the buyer the ownership of the DID of the object). More
>>> importantly, we discovered that with VC, an owner of it can show very
>>> easily that he/she is actually the owner of it, making life easier for our
>>> use case. However, we had a question regarding this:
>>>
>>> - In the standard, we can see the possibility of transferring VCs. Based
>>> on the diagram of the standard (Figure 10 in
>>> https://www.w3.org/TR/vc-data-model/), it looks like the holder of a VC
>>> can transfer it to another holder without involving the issuer. Would this
>>> be possible somehow? This is crucial for our use case, since we want to
>>> decentralise as much as possible our solution. We wouldn't like any 3rd
>>> party or intermediary stopping the holder of a VC from selling it to
>>> another holder. Remember at this point that we see VCs as NFTs (maybe our
>>> assumption is wrong), that's why we would like to decentralise this.
>>>
>>> If transferring a VC from holder A to holder B is not possible without
>>> involving the issuer, do you think this could be done with a Smart
>>> Contract? I know this may not be the best forum to ask this, but we somehow
>>> visualise the idea of using a smart contract as the issuer of DIDs so that
>>> everybody could trust the issuer at any point.
>>>
>>> Thank you very much in advance. I would really appreciate your input on
>>> this :)
>>>
>>> Best regards,
>>> Eric
>>>
>> --
>> Leah Houston M.D.
>> President and Founding Partner
>> www.hpec.io
>> Humanitarian Physicians Empowerment Community
>> Humanitarian Physicians Empowerment Coin
>>
>>