Re: [toolsCCI] Example Immunoglobulin Detection Test Credential

CC'ing the W3C Mailing list, since this discussion of COVID-19 Credentials
has been discussed there as well...

Most of the attributes are just leftovers from basing the credential on a
Permanent Resident Card.

I'm not sure how the VC Data Model values would be collected, but it's
sometimes the case that an organization will use birthdate, gender and name
to double check that things like SSN / Driver's License are accurate (I've
seen this kind of overcollection in healthcare, for this exact reason)...
people make mistakes when entering data, having a group of values to check
against, helps mitigate the damage caused by these mistakes, but it's not a
perfect solution.

I was expecting some request for a binding to a SSN / Drivers License...
I'm not sure that's actually a good idea, but I'm not an expert.

My thought was that this credential could be provided by a laptop computer
in a tent, to people who have no existing identification (persons
experiencing homelessness, refugees, etc...)

Obviously you don't need a picture or any of the PII fields if you are just
going to bind to another identity system like drivers license number... but
that credential won't work for people who are not registered...

The credential format could be expanded to include either a binding to a
well known identity system, OR the current approach... that might give us
the best of both worlds.

If you can leave comments on the PR, that will help make sure that other
communities (outside of these mailing lists) can see your thoughts.

Thanks for the feedback!


On Fri, Apr 10, 2020 at 9:11 AM Daniel Hardman <>

> Regarding Eric's comments about identifying the subject:
> The strategy proposed in the schemas doc in a couple places [1
> <>,
> 2
> <>]
> is to provide just enough information about the holder to let them be
> linked to other credentials (physical or digital/VC) that provide strong
> identification as needed. Orie's example is mostly aligned with this
> proposal, though its birthdate + photo may be a little more than is needed.
> The reasoning behind this is that a lab isn't going to be authoritative
> about facts of birth, and probably isn't going to take a photo of each test
> subject, but probably will check a stronger form of ID when the test sample
> is submitted -- so whatever form of ID they check, they need to embed just
> enough info about the holder in their results to allow the holder to
> present the same strong identification later.
> An example of how this could be tweaked to embody the proposal a little
> better might be to remove the photo and birthdate fields, and to add the
> following two fields:
> presentedIDType: a picklist with strings such as "drivers license",
> "passport", "national ID card", etc
> presentedIDNumber: the number from whatever strong identification the test
> subject supplied when submitting the sample
> Now it becomes clear how Eric can explain the trust dynamics to a harried
> government official: "The testing regime has the same trust dynamics as our
> national ID card/passport/driver's licenses, because that form of ID has to
> be used to submit a sample, and the same ID has to be used when presenting
> the test results."
> On Fri, Apr 10, 2020 at 3:58 AM Eric Welton (Korsimoro) <
>> wrote:
>> Fantastic!  Thanks!
>> I have a two questions and am thinking about how I could
>> summarize/present this to a government minister and relate it to a paper
>> form version of the same.
>> First question: what is a TestCard? and what role does that play?
>> Second - and this is a question that is more "general" - i'm not
>> nitpicking this specific example, but wondering more about credential
>> design in general and how we want to deal with the issue of subject
>> identification:
>> - in addition to IgG and IgM - the context explicitly out a name-pair,
>> birthday, and something to do with the subject's sexuality, and the Person
>> structure from is called out, where most of the fields in the
>> Person model are not particularly useful for identifying a Person but more
>> about "describing" a Person or Person-like thing.
>> Taken together, the presented information doesn't let me easily point to
>> a Person in a way that is immediately useful to me - for my use cases, I
>> would imagine one of the two:
>> - a national id number or semantic model, with optional image (citizens)
>> - a passport semantic model, with optional image (foreigners)
>> I don't see this as a deep problem, because I can always build up context
>> that matches the identification context relative to my expected use context
>> - e.g. I want a checkpoint guard to be able to see the IgM/IgG information,
>> an F2F presented plastic national id card or passport, and make a policy
>> enforcement decision.
>> So the question is just more generic - drawing on this example as a
>> starting point and using it to explore guidance - how can we do this
>> systematically so that we don't have covid credentials that vary for every
>> issuance context based solely on the properties of "subject identification"?
>> One option is to push that out of the credential entirely, and let that
>> come from the wallet or alternate documents provided during presentation -
>> linked only by cryptographic material.  But that brings in a raft of
>> problems and would be a hard sell in a 30 second elevator pitch to a busy
>> and distracted government minister - especially one with a mental model of
>> a physical form with tons of lateral information on it.
>> The other option is to try to "define the subject information" in the
>> credential over and over - like, family name, given name, birth date,
>> sexual idiosyncracies, DUNS number, brand, funder, honorificSuffix,
>> interactionStatistic, product offerings, performances, employer, or many of
>> the other Person attributes ;)
>> Perhaps a strategy of figuring out how to pool information in loosely
>> coupled groups - e.g. only the Ig* values in one group, the person
>> identification in another - perhaps as a one-or-more-of-many selection -
>> there might be a pattern we can establish here that clearly isolates the
>> human-identification-variability from the relatively stable science-driven
>> covid-19 data.
>> again - my concern is for explaining this to a non-technical politician
>> as soon as Monday - and we assume that person has an existing mental model,
>> one that looks like "all the other test result documentation" they've seen
>> - with a bunch of socially-specific subject identification information,
>> issuer identification information, document photocopies, and signatures,
>> stamps, and more signatures, and more stamps - in red, for extra
>> authentication and security.
>> best,
>>   -e
>> On Fri, Apr 10, 2020 at 1:06 AM orie <> wrote:
>>> Based on the new definitions for COVID-19 testing facilities
>>> and the DHS SVIP hypothetical Permanent Resident Card.
>>> Issued from a did:web, Presented by a did:key.
>>> Comments welcome.
>>> --
>>> Chief Technical Officer
>>> <>
>>> _._,_._,_
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Chief Technical Officer


Received on Friday, 10 April 2020 15:54:47 UTC