- From: David Chadwick <D.W.Chadwick@kent.ac.uk>
- Date: Mon, 13 Apr 2020 08:49:38 +1200
- To: public-credentials@w3.org
On 13/04/2020 08:40, Dmitri Zagidulin wrote:
> There's an important aspect that's missing from these schemas so far
> -- the batch number (or even the individual ID) of the tests themselves.
that is not missing from the VC that we use and that I circulated to the
list earlier.
I ran my proposed VC contents past some medics and they were happy with
its contents.
Kind regards
David
> Consider the tests that the UK gov't ordered recently, which turned
> out to have a 10% positive and negative false rates, so they sent them
> back, asked for refunds, and so on. There's many different sources of
> the tests, many iterations within a source, and a difference between
> the batches, even, and all those things have an effect
> epidemiologically (once it turns out, for example, that a set of tests
> has a too-high error rate, so those credentials have to be revoked, etc).
>
> On Sun, Apr 12, 2020 at 3:58 PM Orie Steele
> <orie@transmute.industries> 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 20:50:06 UTC