- From: D.W.Chadwick <info@verifiablecredentials.info>
- Date: Mon, 13 Apr 2020 08:28:05 +1200
- To: Orie Steele <orie@transmute.industries>
- Cc: main@toolscci.groups.io, Adrian Gropper <agropper@healthurl.com>, "W3C Credentials CG (Public List)" <public-credentials@w3.org>
hi Orie
I think the biggest question in your list is online or offline use. Is
the Internet available or not? To all the actors or just a subset of
them? This is the biggest requirement that needs to be addressed first
before we go much further.
Kind regards
David
On 13/04/2020 07:57, Orie Steele wrote:
> I'm having trouble parsing paragraphs of text into requirements...
> Lets avoid bluetooth / qr codes until we get these credential format
> fields documented formally somewhere...
>
> Let's describe the credential types using the VC Data Model
> terminology: Issuer, Holder, Verifier, Subject, Claims, etc...
>
> Let's describe each credential as a set of inputs and outputs...
>
> Here are some assertions, we should probably get consensus on first:
>
> Subjects will need to be tested multiple times...
>
> TestSubject (Holder)
> - Has internet access.
> - Has identification card with image, type and number.
>
> TestingFacility (Issuer of SampleCollectionCredential)
> - Has a DID.
> - Has internet access.
> - Has website
> - Has location, address / gps
> - Can only issue a SampleCollectionCredential, a form of receipt that
> a sample was collected and will be tested.
> - Will not test someone who has no form of identification / contact
> ability. (is this true?)
>
> SampleCollectionCredential
> - credentialSubject.id is hash of (subject identification card type
> and number + 8-digit-pin)
> - identification card type.
> - testResultEndpoint (
> https://example.com/covid-19/test/credentialSubject.id )
> - expiration
>
> TestingLab (Issuer of TestResultCredential)
> - Has a DID.
> - Has internet access.
> - Has website
>
> TestResultCredential
> - credentialSubject.id is hash of (subject identification card type
> and number + 8-digit-pin)
> - IgM boolean
> - IgG boolean
> - expiration
> - is publically accessible without any form of authentication (is this
> true?)
>
> TravelEnforcmentPerson (Verifier of Credentials)
> - Has internet access.
> - Can review identity documents
> - Can verify credentials
>
> I worry that assuming the subject will have a DID or be able to do
> anything but present a bearer token to the verifier is an unreasonable
> assumption.
>
> In order for a bearer token to be acceptable, it will need to be bound
> to some identity system which includes an image.
>
> Are we assuming the Subject / Holder has a DID or not?
>
> OS
>
>
>
> On Sun, Apr 12, 2020 at 1:56 PM D.W.Chadwick
> <info@verifiablecredentials.info
> <mailto:info@verifiablecredentials.info>> wrote:
>
> Hi Eric
>
> Thankyou for your very detailed discussion below.
>
> A lot of your comments below are about the topic of "Attribute
> Aggregation", whereby the holder collects together attribute
> assertions
> from many different issuers and submits them either concurrently or
> sequentially to the verifier. I think this is the correct way to
> go for
> medical certificates of all kinds, since each attribute assertion (or
> VC) is independently collected by the user, each issuer acts
> independently of the others and does not need to know anything
> about the
> other issuers or the attributes they issue, and the *data model and
> protocol* should provide a mechanism whereby the holder can
> collect the
> set and prove possession of the entire set that he/she presents to
> the
> verifier.
>
> We implemented such a system many years ago for federated identity
> management using SAML, and Open ID Connect now supports this
> feature in
> its protocols (as does our COVID-19 Immunisation Certificate
> verifiable
> credential middleware). In our case the unifying feature is a
> transient
> public key in each assertion, and the holder signs the
> presentation to
> prove possession of the collection.
>
> As you say, we certainly should not be asking the user to remember
> yet
> another password. Such cognitive overload is unnecessary.
>
> Working offline as your require, it is impossible to achieve the
> above,
> because offline working does not allow transient identifiers to be
> used.
> Persistent IDs must be used in this case, and each presentation
> (big QR
> code) will be the same and contain the same linking ID, thereby
> losing
> some of the holder's privacy. But these sorts of trade-offs are
> necessary, as no system can provide all the most desirable features.
>
> So whether the linking id is transient or persistent will depend upon
> the use case.
>
> I would add that using persistent IDs with offline working introduces
> the added complexity of revocation. What happens when the paper QR
> code
> given to a person becomes invalid because a new strain of COVID-19
> has
> arisen, meaning that their immunity is no longer valid. You might
> argue
> that you could build in blanket refusal to everyone with a similar
> immunity certificate, but this might be too blunt an instrument. It
> depends upon the science of immunity, of which I know nothing.
>
> kind regards
>
> David
>
> On 13/04/2020 04:02, Eric Welton (Korsimoro) wrote:
> >
> > My original concern about the proposed VC involved the linking of
> > id-proofing material with the medical data. For example
> > {
> > { IgG...., nameData...., humanSexualityFields....,
> > schema.orgPersonDescriptions..... }
> > }
> > And this was replaced with the following model
> > {
> > { IgG...., identityDocumentLinkData.....}
> > { identityDocumentLinkData...., restOfIdentityData..... }
> > }
> > where identityDocumentLinkData included an "identity document
> type",
> > and a field value for the externally defined "primary key like
> field"
> > for that identity document type. The example given was the highly
> > u.s. specific "Driving License", but could easily be extended to
> > include other identifying document, like national ids. This
> however,
> > introduces "low-value complexity" because of the need to have the
> > medical information model include a semantical model of allowable
> > identity-proofing documents - for example, are Saudi Arabian
> Iqama's
> > or Thai Resident Laborer Alien Cards ("Pink Cards") or United
> States
> > IR-visa cards acceptable? Where is this registry maintained -
> because
> > it is required so that you can look up the appropriate "field
> name" in
> > the id-proofing data - either that or you start pulling even
> more of
> > the id-proofing metadata into the medical information.
> >
> > And what does this identity proofing data have to do with the raw
> > medical information? All of this complexity can be avoided by
> simply
> > taking advantage of the adjacency of the credentialSubject material
> > and the fact that there is a unifying signature over that data -
> as in
> > {
> > {.... medical information }
> > {.... id-proofing data, "this is a <name of document type>" }
> > } => signature (or hash)
> >
> > This lets you focus on modeling the medical information
> independent of
> > the identity-proofing information, and lets the verifier,
> holder, and
> > issuer use the id-proofing information as is appropriate to the
> > context. It does not mandate, for example, disclosure of a Social
> > Security Number to a medical testing lab.
> >
> > We also have a need to associate multiple pieces of medical
> > information, which are produced later - in different times and
> places
> > - with the identiity information. For example - blood collected
> at a
> > medical intake facility might produce an initial record
> > (SampleCollectionCredential) like
> > {
> > { linkCode = <collision-resistant-pii-free-identifier> }
> > {.... medical information }
> > {.... id-proofing data, "this is a <name of document type>" }
> > } => signature
> > where the medical information may be nothing more than a bar-code
> > printed on a label printer and attached to a test-tube, or may
> be more
> > sophisticated - as long as it is PII free. Location, facility,
> > attendant and that sort of information is split across the medical
> > information and issuer identification as appropriate - or perhaps
> > there are other data blocks {.... facility information } or {....
> > weather conditions }, etc.
> >
> > At a later time, the above SampleCollectionCredential is used to
> > produce the following TestResultsCredential
> > {
> > { .... linkCode }
> > { .... second medical information }
> > { .... third medical information }
> > } => signature
> >
> > where the lab facility and processing information is again split
> > between the issuer and the medical records - perhaps there are
> serial
> > numbers of re-agent lots or testing-kid GTIN/NTIN numbers, or
> any bits
> > of other data TBD.
> >
> > Importantly, no PII is used to link these records - it is an
> arbitrary
> > id, and not sha256(id-proofing-document-type,
> > id-proofing-document-primary-key-field-value,
> > 8-digit-one-time-use-passcode). Use of a purely random collision
> > resistant identifier, like a UUID or public-key fingerprint, avoids
> > the problems inherent in id-proofing document meta modeling (which
> > require that we have a central registry of allowable id-proof types
> > and models which minimally allows us to identify the primary key
> field
> > in the id-proofing data model)...
> >
> > It also avoids placing the cognitive burden on the subject for
> > remembering yet another passcode - which they should probably write
> > down on whatever document is provided. For example, a feasible
> way to
> > maintain reference to the data is through a couple of QR codes
> > pointing to cloud-backed storage of the information, such as
> > http://example.com/covid/collection/<linkCode>?password=12345678
> > with the later-produced lab results available at
> > http://example.com/covid/results/<linkCode>?password=12345678
> >
> > Importantly, the password is just encoded in the QR code, but
> > otherwise in plaintext. If we force the user to memorize the
> > password, we should provide a way to to record the user's
> password and
> > allow them to recover it, as remembering "yet another series of
> random
> > digits" is very, very difficult. Perhaps they could "store it in
> > their phone" as a fake phone number, or write it down on a little
> > sticker, or we can give them a password recovery password, which
> > itself would need a password recovery password recovery password,
> > which itself would need a ...... Perhaps we could let them
> > "authenticate with google" or use their facebook login to
> retrieve the
> > password automatically....
> >
> > The difficulty of supporting this password makes me want to step
> back
> > and look at the role it plays. The need to restrict access to
> > information is *critical* when the medical information contains
> > personally identifying information, such as is the case in this
> model
> > {
> > { medical information...., idType=texasDriversLicense,
> > idPrimaryKey="12345" }
> > { detailed id-proofing information, idType=texasDriversLicense,
> > texasDepartmentOfPublicSafetyNumber="12345" }
> > }
> > and, the subsequent test results are modeled as
> > {
> > { hashOfPII_and_Password }
> > { test1Results..... }
> > { test2Results..... }
> > }
> > but it is less of a concern when modeled as
> > {
> > { <collision-resistant-arbitrary-pii-free-identifier> }
> > { medical information.... }
> > { detailed id-proofing information, idType=texasDriversLicense,
> > texasDepartmentOfPublicSafetyNumber="12345" }
> > }
> > and, the subsequent test results are modeled as
> > {
> > { <collision-resistant-arbitrary-pii-free-identifier> }
> > { test1Results..... }
> > { test2Results..... }
> > }
> >
> > In the latter there is no strong connection between the source and
> > result data, but the connection is there and acceptance of it is a
> > matter of personal taste and the reality of the sponsoring
> agency or
> > health authority operating the initial point of medical contact and
> > testing. Subjects should not trust any random person sitting in a
> > cardboard box under a bridge with collecting their blood and
> promising
> > they'll send it for testing - rather, there is some organization
> > making the outreach and contracting with testing labs. It is *this*
> > organization which is in a position to provide some level of access
> > control, such as running the example.com <http://example.com>
> <http://example.com> website
> > allowing subjects and policy enforcement officers to access the
> data
> > later on.
> >
> > In terms of "logging on to the lab website" rather than through the
> > example.com <http://example.com> <http://example.com> website,
> is a secondary consideration
> > which may or may not make sense. In either case, the
> orchestrators of
> > the collection process have first-line access to id-proofing
> material,
> > and this material can be used to log in later - perhaps making
> use of
> > any of the numerous services that provide direct verification of
> > primary id-proofing documents. Alternatively, sponsoring
> organizations
> > are likely to require that users download an "app" for the devices
> > that manage those users, and use a "log in with facebook" model
> for a
> > web-site serving non-device managed people.
> >
> > The business concerns of that sponsoring organization, or of the
> lab's
> > business models should not influence the credential design - but
> they
> > do benefit from maximum separation of concerns within the
> credential
> > design. This gives the most flexilibity and minimizes PII
> liability.
> >
> > Jurisdiction also plays a huge role - at MyData 2019 i saw a
> slide (I
> > am blanking on whose presentation) - but it listed three
> approaches to
> > data. The american approach where data control belongs to
> businesses,
> > the chinese approach where data control belongs to the state,
> and the
> > european model where data control belongs to the individual. The
> > organization supporting the testing and issuance, and any direct
> > access to results via the testing lab or 3rd parties, will
> operate in
> > one of these contexts. It is not the responsibility of the covid
> > credential model to take a position on this - rather it must remain
> > orthogonal to these concerns. This means that ensuring individual
> > control over the use of the data is *not* in scope while making any
> > structure which *prohibits* control over the data must be avoided.
> >
> > What we must maximize is the independence of data points - maximize
> > the separation of concerns - because this and only this gives us
> the
> > flexibility we need to operate on a global scale.
> >
> > We also need to note that, while the initial { medical
> information...
> > } can be PII free, the following test results may or may not be PII
> > free - depending on the depth and detail of the test. If the
> test is
> > only about "antibody present/absent" - then it is not PII
> sensitive,
> > but if it contained detailed analysis of a set of genetic
> markers such
> > that it was effectively a DNA fingerprint, then one might argue
> that
> > it was PII. This influences the acceptability of the other
> components
> > and the risks inherent in the linkability of data - and it is
> > sensitive to your operating context.
> >
> > A great deal can be achieved in mitigating the current virus
> > distribution by supporting only low-PII rest results, and zero-PII
> > linking keys.
> >
> > Regardless of PII exposure in the testing pipeline - the
> verification
> > context we seek looks like this:
> >
> > /1. subject approaches policy enforcement officer and presents/
> > /1.1 - QR code (digital or analog)
> > /
> > /1.2 - original identity proofing document (digital or analog)
> > /
> > /1.3 - self (analog)
> > /
> > /2. policy enforcement officer..../
> > /2.1 - scans QR code and retrieves id-proofing data for
> > <collision-resistant-arbitrary-pii-free-identifier> (performing
> issuer
> > verification)
> > /
> > /2.2 - makes judgement call as to whether id-proofing matches,
> using
> > whatever tools are appropriate - this could include everything
> from a
> > checkpoint guard simply looking at the photo on their screen, along
> > with basic demographic data and then looking at the person in
> front of
> > them - or it could be more sophisticated, using biometrics ranging
> > from facial recognition to voice printing and fingerprints./
> > /2.3 - optionally requests some indication from the subject to
> > "release" the test results - but this is optional, and depends upon
> > the tooling available to the policy enforcement officer and the
> > subject and the context - this is roughly equivalent to the use
> of the
> > PIN, but could be expanded (if SSI enabled) to include consent
> > tracking (in situations where that is relevant)
> > /
> > /2.4 - retrieves the relevant test results (performing issuer
> > verification) and determines appropriate course of action -
> allowing
> > the subject to continue, blocking the subject, or detaining the
> subject/
> >
> > Note that the subject is almost entirely passive. The digital
> > signatures support the identification of the issuer - and that can
> > easily be tied in with existing PKI, where that exists, as well as
> > using DIDs if that works - this is determined by the policy
> > enforcement context. Data could be presented by the subject either
> > digitally or analog, as is appropriate to the context. What we
> > generally do not need is the subject to engage in negotiation,
> or be
> > able to "forget a password" or otherwise hose up the policy
> > enforcement pipeline. Imagine how long it would take to get on the
> > subway if everyone had to "haggle" a ticket price - it is bad
> enough
> > using PIN based debit cards, which is why the typical subway
> access is
> > mediated by side-loaded stored-value systems - which excludes
> "putting
> > in a PIN" from the primary enforcement pipeline - this is the
> > sensibility we need to pursue.
> >
> > What is horrific about the above model is that the policy
> enforcement
> > is going to a central database that has "all the records" - that is
> > kinda what we want to avoid. To avoid this we need to get a third
> > credential - and ideally one that is "fit for purpose" (e.g.
> tailored
> > to the policy enforcement need, and perhaps sponsored by/issued by
> > that agency) - or, alternatively, one that is generic - in which
> case
> > it should be offered by some common agency which is financially
> > supported by the policy enforcement agencies.
> >
> > Such a third party might be related to the same agency
> supporting the
> > testing tents and outreach - and the same considerations about
> > "logging in" apply.
> >
> > What is important is that these tertiary credentials can
> effectively
> > act like a zero-knowledge-proof or a ZCAP key. For example - let's
> > imagine that I wanted to screen people at an inter-state border,
> only
> > allowing people to enter my state if they could prove that they had
> > recently been tested and are negative. What I want at the
> border is a
> > very fast test with no network access - like scanning a "big QR
> code"
> > - it is easy to imagine a system with this verification strategy:
> > 1. subject approaches policy enforcement officer (or system) and
> presents
> > 1.1. self (stares into camera)
> > 1.2 qr code (holds up to camera)
> > 2. policy enforcement officer (or system)
> > 2.1 performs facial recognition between self and image encoded
> in qr
> > code and/or bound to id-proofing document
> > 2.2 checks that 'virus testing result' matches policy
> > 2.3 verifies issuer credentials
> > 2.4 makes policy decision (for example, raises gate and allows
> subject
> > to pass)
> >
> > This would be completely feasible - it has no network round
> trips so
> > there is no essential central honeypot of test results.
> Furthermore,
> > the subject could (in jurisdictions with GDPR-like legislation)
> > request that any central records of the first stages be deleted,
> > meaning that the QR code (either on a sticker or in their phone
> or any
> > other device that manages them) is the only record of the data -
> yet
> > it was born with a chain-of-evidence and data-provenance which
> > provides strong indication of trustworthiness.
> >
> > You can also imagine that later, as this ecosystem matures,
> tertiary
> > credentials could be issued almost automatically - using the ever
> > improving systems that support online verification of the original
> > id-proofing document, along with liveness checks and strong
> > audio/visual biometrics - and this brings us to *SSI* and *cloud
> > agents*. All of the above can be improved through the use of SSI
> > technology - be it either cloud-agents or edge-agents. What is
> > essential is that the process is possible without SSI
> technology. SSI
> > and private-key management must be an enhancement to this
> process, not
> > a requirement.
> >
> > Furthermore, SSI agents enable advanced control over the further
> uses
> > of testing associated information - where agents are understood
> > generically - perhaps they are Aires agents, or perhaps they are
> > HIE-of-one Trustees. Until that infrastructure is ubiquitous and
> > business practices and policy enforcement endpoints are well
> poised to
> > make use of them, we must not require it. We are building
> towards a
> > world where our solution looks like this
> > {
> > {.... medical information }
> > {.... did }
> > } => signature (or hash)
> > And where eventually we will use the service_endpoints of the
> DID to
> > answer every request for id-proofing data with the question "who
> > want's to know" and make a private-policy driven decision for
> > information release, therefore giving the individual control
> over all
> > exchanges of their health information - we just aren't there
> yet. On
> > the other hand, this is a phenomenal opportunity for bootstrapping
> > that universe if we can find just the right way to sidestep the
> > chicken-and-egg problem.
> >
> > The only step that can be taken - at this point - is isolating, as
> > early as possible, PII from medical information and break from
> > traditional practices, which would use PII in place of
> > opaque-identifiers. This is a significant step forward - as it is
> > extremely tempting to start out with data using structures like
> > {
> > IgG...
> > IgM...
> > gender....
> > firstName...
> > lastName...
> > address....
> > mobileNumber...
> > emailAddress...
> > }
> >
> > So - I think we can make a huge step forward using the
> technology we
> > have and deploying it in a way that works for DID and phone free
> > individuals, and supports rapid, low cost, offline deployment in
> > front-line policy enforcement scenarios across all tiers of
> technical
> > capabilities. We can achieve these goals with this model:
> > *Sample Collection Credential:*
> > {
> > { linkCode = <collision-resistant-pii-free-identifier> }
> > {.... medical information }
> > {.... id-proofing data, "this is a <name of document type>" }
> > } => signature
> > *Test Results Credential:*
> > {
> > { .... linkCode }
> > { .... second medical information }
> > { .... third medical information }
> > } => signature
> > and derive *Rapid Clearance Credentials* (QR encoding) to
> facilitate
> > zero-network, minimal-PII, high quality, point-of-enforcement
> decision
> > making.
> >
> > This is something we have all the tools to deliver quickly. Maximal
> > separation of data concerns minimizes risk of abuse and can
> adapt to
> > worldwide conditions across a huge range of technical
> realities. This
> > opens the door to improvement via SSI technology - specifically
> agents
> > and trustees, and sophisticated personal information wallets.
> >
> > best,
> >
> > -e
> >
> >
> > On Sun, Apr 12, 2020 at 12:28 AM orie
> <orie@transmute.industries> wrote:
> >
> > Based on feedback from Daniel Hardman and Adrian's comments, I'm
> > planning on implementing a new ImmunoglobulinDetectionTest
> schema.
> >
> > The first format was aimed at anyone with a face, and assumed a
> > cassette test and that the credential subject has a DID.
> >
> > There pros and cons to that approach... the most obvious con is
> > that absolutely nobody has DIDs.
> >
> > I like the idea of splitting up the sample collection part and
> > rest results part into 2 credentials, and using existing
> > identifiers and hashing to link them.
> >
> > Here would be the new user story:
> >
> > 1. Subject drives up to a tent in a parking lot.
> >
> > 2. Testing Facility Checks some id ( "presentedIDType: a
> picklist
> > with strings such as "drivers license", "passport", "national ID
> > card", etc " )
> >
> > 3. Testing Facility Collects blood sample and issues a
> > "SampleCollectionCredential"
> >
> > subject = sha256 ( presentedIDType + presentedIDNumber +
> 8-DIGIT-PIN )
> > presentedIDType (repeated in credential)
> > testResultURL: https://example.com/covid-19/vc-test-results/ (
> > subject )
> >
> > credential is provided on paper, to the subject after sample is
> > taken (multiple copies are provided, and it's safe for them
> to be
> > copied further).
> >
> > 4. sample get sent to lab... days go by, etc...
> >
> > 5. Subjects can check a registry for their test results,
> when test
> > results are ready they are published at a URL, which is provided
> > to them in their credential.
> >
> > testResultURL: https://example.com/covid-19/vc-test-results/ (
> > subject )
> >
> > 6. Subject can present test results to TSA / Law Enforcement
> when
> > traveling by presenting their "SampleCollectionCredential" ,
> > whatever ID type they used for it, and disclosing their 8
> DIGIT PIN
> >
> > 7. Verification is as follows
> > 7.1 confirming the face / gender / eyes / height (etc) of the ID
> > Card used for "SampleCollectionCredential"
> > 7.2 Verify "SampleCollectionCredential" (no VP here, since the
> > subject has no keys / DID).
> > 7.3 Confirm subject = sha256 (
> > presentedIDType + presentedIDNumber + 8-DIGIT-PIN ) (website
> helps
> > them do this)
> > 7.3 Lookup testResultURL:
> > https://example.com/covid-19/vc-test-results/ ( subject )
> > 7.4 Verify "SampleTestResultCredential"
> > 7.5 Apply allow / deny list (any other business logic rules)
> >
> >
> > Only the issuers would have DIDs in this scenario, and there
> would
> > be no signed verifiable presentations.
> >
> > anyone with presentedIDType + presentedIDNumber + 8-DIGIT-PIN,
> > could claim a test result belonged to them, and its the
> > responsibility of the verifier to check the presentedIDType.
> >
> > Assuming that the presentedIDType where digital and
> > that SampleCollectionCredential were digital, a Presentation
> that
> > included the disclosure of the 8-DIGIT-PIN could be made
> over any
> > transport that was supported ( CHAPI / DIDComm / Bluetooth )
> >
> > OS
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > On Sat, Apr 11, 2020 at 5:40 PM Adrian Gropper
> > <agropper@healthurl.com <mailto:agropper@healthurl.com>
> <mailto:agropper@healthurl.com <mailto:agropper@healthurl.com>>>
> wrote:
> >
> > inline...
> >
> > On Sat, Apr 11, 2020 at 6:06 PM Orie Steele
> > <orie@transmute.industries> wrote:
> >
> > I'm not sure the exact context but I think the following
> > is equivalent to what you are suggesting.
> >
> >
> > The context is getting through a door by showing the bouncer
> > your phone the way you might a driver's license. This is not
> > like showing a boarding pass to the gate agent because
> there's
> > no pre-registration. The main issue in this context, is
> > whether the bouncer thinks you've borrowed somebody else's
> > license or tampered with your own license. There is no
> privacy
> > issue as long as the bouncer promises not to save any PII
> > after he makes a decision to let you in or not.
> >
> >
> > 1. Testing facility draws blood from people with
> driver's
> > licenses.
> > 2. Testing facility labels samples with unique id =
> > sha256(drivers license + salt).
> >
> > 3. When I log into the lab (how? by email, phone
> number?,
> > anybody can see results?)... I can find the result of my
> > test, which contains no PII, by knowing my drivers
> license
> > number and the salt.
> >
> >
> > By the hash. The hash was generated by your wallet. The lab
> > never sees the actual driver's license.
> >
> > The lab issues a VC to the hash that includes your test
> result.
> >
> > 4. When someone asks for my results, I can show them my
> > drivers license and disclose the salt, and the can go
> > download the results themself, or confirm that the
> results
> > I provided have the same identifier... but I also need
> > them to believe that whatever I provided them has
> not been
> > tampered with, hence they also verify the VC.
> >
> >
> > I'm not sure about the salt. If I trust the verifier not to
> > store the data from my driver's license, I can let them
> > calculate the hash (with salt) and match it to the VC
> that was
> > issued to the hash.
> >
> >
> > There are a couple things combined in these which it's
> > probably a good idea to seperate.
> >
> > 1. VC Format (sample identifier is a deterministic
> > function of an existing identifier, and we trust the
> test
> > facility to generate this).
> >
> >
> > Not necessarily. The association between the sample and the
> > driver's license may be made by a nurse that draws the
> blood.
> > The nurse saves nothing but might sign the hash with her
> > credentials in order to be held accountable.
> >
> > 2. VC is signed at the lab, not at the point of
> > collection... so we trust the lab, they are the issuer,
> > and we trust them not to change the identifier from the
> > facility... the lab does not need any PII to do its
> job...
> > unless they provide a web portal to log in with pii.. if
> > they just disclose test results publically, then they
> > don't need PII.
> >
> >
> > Yes, mostly. The result is accessed by the hash. This is
> > similar to how COVID bluetooth proximity schemes (Google and
> > Apple announcement) are based on pseudorandom rotating IDs
> > that can only be re-identified by the issuing app which is
> > under the control of the subject (the wallet).
> >
> > 3. VCs are disclosed via some permission system
> (login)...
> > not defined, but I would assume sms / email / IAL Level
> > 2... implies the lab needs PII. or that the login
> > mechanism is knowing a sample-id...
> >
> >
> > No. The lab has zero PII.
> >
> > 4. Presentation of the VC includes the disclosure of
> > information which can be used to bind an existing
> > identifier (drivers license) to the rest results...
> >
> >
> > Yes.
> >
> >
> > VCs for tests that have to be retrieved from the lab are
> > harder than ones that come from a facility that just
> does
> > everything, which is why i tackled the easy case
> first...
> > but I guess its probably much more realistic that people
> > would have to wait / lookup their results.
> >
> >
> > Yes.
> >
> > Thank you,
> > - Adrian
> >
> >
> > OS
> >
> >
> >
> > On Fri, Apr 10, 2020 at 9:06 PM Adrian Gropper
> > <agropper@healthurl.com
> <mailto:agropper@healthurl.com> <mailto:agropper@healthurl.com
> <mailto:agropper@healthurl.com>>>
> > wrote:
> >
> > Apologies if I missed the answer elsewhere but I'm
> > lost when it comes to the photo on a driver's
> license.
> > I'll ask again:
> > - The state driver's license in my pocket has a
> photo,
> > a license number, and some tamper-resistant
> features.
> > - When I go get a serology test, the person
> drawing my
> > blood might look at my license, write a hash of my
> > license number and photo on the tube and send to
> the lab
> > - I log in to the lab, search for the hash that was
> > put on the tube and download the result to my wallet
> > - When someone asks for my result, I show them my
> > driver's license with my photo and the hash of the
> > number matches the VC I received from the lab
> >
> > So,
> > - My photo and the driver's license number never
> left
> > my wallet.
> > - A tamper-resistant scheme has to prevent me from
> > changing the photo on my license without also
> changing
> > the hash that labels the sample and the result.
> >
> > What am I missing?
> >
> > - Adrian
> >
> > On Fri, Apr 10, 2020 at 11:56 AM Orie Steele
> > <orie@transmute.industries> wrote:
> >
> > 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!
> >
> > OS
> >
> >
> >
> > On Fri, Apr 10, 2020 at 9:11 AM Daniel Hardman
> > <daniel.hardman@evernym.com
> <mailto:daniel.hardman@evernym.com>
> > <mailto:daniel.hardman@evernym.com
> <mailto:daniel.hardman@evernym.com>>> wrote:
> >
> > Regarding Eric's comments about identifying
> > the subject:
> >
> > The strategy proposed in the schemas doc
> in a
> > couple places [1
> >
> <https://docs.google.com/document/d/1F5TLvAqCxj1kaPuPe6JhdECixwpbhKpEAb8eeQuDGT4/edit?disco=AAAAGVNlqxU>,
> > 2
> >
> <https://docs.google.com/document/d/1F5TLvAqCxj1kaPuPe6JhdECixwpbhKpEAb8eeQuDGT4/edit#heading=h.31e94ad08nhb>]
> > 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) <eric@korsimoro.com
> <mailto:eric@korsimoro.com>
> > <mailto:eric@korsimoro.com
> <mailto:eric@korsimoro.com>>> 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
> > schema.org <http://schema.org> <http://schema.org> 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
> > <orie@transmute.industries> wrote:
> >
> > https://github.com/w3c-ccg/vc-examples/pull/30
> >
> > Based on the new schema.org
> <http://schema.org>
> > <http://schema.org> 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.
> >
> > --
> > *ORIE STEELE*
> > Chief Technical Officer
> > www.transmute.industries
> >
> > <https://www.transmute.industries>
> >
> >
> >
> > --
> > *ORIE STEELE*
> > Chief Technical Officer
> > www.transmute.industries
> >
> > <https://www.transmute.industries>
> >
> >
> >
> > --
> > *ORIE STEELE*
> > Chief Technical Officer
> > www.transmute.industries
> >
> > <https://www.transmute.industries>
> >
> >
> >
> > --
> > *ORIE STEELE*
> > Chief Technical Officer
> > www.transmute.industries
> >
> > <https://www.transmute.industries>
> >
> > _._,_._,_
> >
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>
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Received on Sunday, 12 April 2020 20:28:29 UTC