The Verifiable Claims Task Force

A Task Force of the Web Payments Interest Group

Verifiable Claims Telecon

Minutes for 2017-02-14

Dave Longley is scribing.
Manu Sporny: +1 To Agenda...
Matt Stone: Any changes to the agenda?
Richard Varn: +1 On agenda
Jonathan Holt: +1, But quick review of 1-5
Christopher Allen: I'd like to talk about some questions related to the portable reputation kit and being able to talk about evidence or the source of your attribution in some fashion. The main thing I want to figure out is if it's a future item, not figure out how to do it.
Christopher Allen: It's fairly short so add as convenient.
Matt Stone: Let's throw it in around #3.
Christopher Allen: Great.
Matt Stone: Any other changes?
Manu Sporny: Yeah, we have at least one, maybe two new people today.
Manu Sporny: Getting intros would be good.

Topic: Introduction to Abbas Ali from R3

Abbas Ali: I just joined, this is my first call. I work at a company called R3, we're a distributed ledger tech company focusing on financial services. Looking at KYC on our Corda platform.
Abbas Ali: Based in NY, looking at using the work you've done around Verifiable Claims for use in product and curious to learn more.
Matt Stone: Great, welcome to the group.
Abbas Ali: Thanks.

Topic: Status of Verifiable Claims WG Creation

Matt Stone: Status of the VCWG?
Manu Sporny: It's still slow going, mostly because W3C staff are trying to work through some of the formal objections, but ... Dave Raggett is pretty much on the case. For those that don't know him, he's been involved with W3C from the beginning, author/lead editor of HTML4. Wrote a good response on the current state of affairs that was very fair. Been emailing behind the scenes to deal with the sticking points. As the weeks go on the formal objections are being whittled away at. Still no idea when the group will be created but it should be real soon now.
Matt Stone: Is addressing the formal objections ... is there a process for the objectors to say "Ok" or does W3C just make a decision and moves on?
Manu Sporny: W3CM just makes a decision and moves on, they modify the charter to address the objections and there's nothing in the process to allow new objections to be raised. They get addressed in the charter and you move on. In general, there has been far too much support for the group to not start it (my personal view); most votes in support for any work at W3C.
Manu Sporny: We had a handful of large orgs dig their wheels in and say "Don't start the work, full stop." Those types of objections take more time to deal with, they didn't outline what would make them happy.
Manu Sporny: We're good for the most part.
Nathan George: +1
Matt Stone: Phil had made a couple of edits to the charter some weeks ago and called out privacy as an issue. Recognizing that was the topic of some of the objections. I'm not sure who's seen that, he edited the charter directly. He called out U-Prove as a technology to look at. From the chairs, we were a little uncomfortable with the language that was put in and we're working to use some alternative content and positioning so we're not going down the path of naming a tech like U-Prove.
Matt Stone: Richard Varn had put together a note we'll send out in the next day or tomorrow on that topic with some the language we like better that's in this area.
Christopher Allen: This is something I would definitely like to take a look at in the sense that I agree and I think it's a requirement that we are able to support selective disclosure approached and future proof ourselves, but it's very very unclear which ones are the appropriate ones to use. And even exactly how what will be required of us to even have that flexibility. There are a number of approaches where U-Prove is more of the more interesting ones because it's been around a while but it also says it's been around a while and it hasn't gotten momentum and there have been improvements in this area since then.
Matt Stone: I think the way we're positioning the content in the charter is that we don't want to pick a winner and U-Prove has been around a while and hasn't won and we shouldn't call it out in the charter.
Matt Stone: This will be a topic over the next year or so as we build the spec.
Richard Varn: This is what we are considering saying: It will further include privacy impact and mitigation in the design and development of the use cases, requirements, and specifications.
Varn quotes from the charter.
Varn quotes from notes.
Manu Sporny: We want to be open and transparent but we need to make sure we keep member-confidential discussions confidential so we can't say more here.
Manu Sporny: +1 To getting back to just the mailing list.
Matt Stone: I'm adding another topic; our agenda today goes out to a W3C mailing list and some individuals. I'd like to just get back to that being just a list. If you're one of the ones that's outside of the list, please join the group and the mailing list and reach out to us off line if you don't so we know why you haven't.

Topic: Sandbox for the implementers to work on

Matt Stone: In other projects like JSON-LD there is a sandbox online where you can submit docs and validate them in real time. We've had some discussions about that for VC and I know the acclaim team has a VC example and we are looking for a way to test it.
Matt Stone: Implementers want to make sure they are producing the right stuff.
Matt Stone: I'd like to get some thinking about it and some volunteers for putting something like that online.
Christopher Allen: I've commissioned and contracted with Noah (and one other) -- and had them do some work with bitcoin signatures and to begin work on a VC playground. They are doing it as they can at this point. I've also been talking with Markus Sabello who did one for XDI and that's some Java playground -- there's some work there and I welcome other participation and hopefully multilanguage.
Manu Sporny: This is something that the group desperately needs. The good news is that there has been some recent revamp to the JSON-LD playground integrating bitcoin signatures with Harlan and Noah and that's great. There's an initiative for further digital signature work and there's a playground for them. Christopher and Noah are working on Linked Data Signatures for the bitcoin curve and Digital Bazaar is working on some stuff with Javascript and python implementations and Gregg Kellogg is working on a Ruby implementation potentially. And others have worked on various playgrounds. We have all the ingredients coming together, someone just has to sit down and do the work. It only took one person a weekend or two to do the first cut of a playground, so not a lot of work. It's something we really need to do, we at least have the base libraries to have a VC playground with RSA and bitcoin curve signatures. Just a matter of getting a team together and working on code for a week.
Matt Stone: Should we make, in the github, VCTF repo, a playground project or series of projects and collect the code there?
Manu Sporny: Yes, and we could publish through github pages that's the playground and it would let us manage and contribute to it through github. We know how to do all that stuff and it's a good way to do it. We can get Christopher, Noah, Harlan, etc. everyone working on that, hosted on github. We should have a separate repo and I can create that if folks are ok with that on the call today. The other thing we want to do that Christopher mentioned is having a repo for VC and we want the spec to support education, financial, healthcare, etc. and collect examples of claims so we can put those in and use them.
Manu Sporny: I don't know where those go (in the playground or a separate place) that's another topic to discuss. If the group wants this, we can move to put it together.
Matt Stone: +1
John Tibbetts: +1
Christopher Allen: +1
Matt Stone: +1 To make playground on github
Dave Longley: +1
Nathan George: +1 From me as well
Jonathan Holt: +1
ACTION: Manu to create github repo for Verifiable Claims Playground.
Matt Stone: Christopher if you're looking for other volunteers, I think we have some Ruby skills on the Acclaim team so we may be able to contribute there. I'm not sure how to engage.
Christopher Allen: Maybe an implementers mailing list, just for people who are focused on writing the code and sharing. One of my main things is ... as I'm talking with various customers and such and we need as many languages as we possibly can that serve enterprise and Ruby is definitely one of them.
Matt Stone: I like the idea of an implementers mailing list.
Manu Sporny: This is the implementers discussion and mailing list. W3C likes to have discussions and code grounded stuff, etc. this is that group.
Matt Stone: So move away from philosophy and into implementation soon.
Manu Sporny: Yes.
Matt Stone: Anything more on the playground?

Topic: Action Item Review

Manu Sporny: I think everyone should be able to see the task list (my personal opinion).
Manu Sporny: Anyone with the link can access and comment.
Joe Andrieu: I closed the one that was mine (1/31), I just want to make sure I understood the use case. I wasn't clear if this was meant to be an ongoing thing where I keep updating issues as we keep going.
Joe Andrieu: The language in the action is very open; I understood the action to be able the specific notes for that meeting.
Manu Sporny: I think you did the right thing but this is a good example of an issue where it's unclear when it's closed. This is a note to folks that raise issues, make sure the issue you raise is actionable and we know when it needs to be closed.
Matt Stone: That's a good reminder, evidence of success and know "when we're done".
Matt Stone: If we got this content in the use case document, then we should close the issue in github as well and stop tracking it there as well.
Joe Andrieu: I'd like to clarify; I took the action item to about getting my notes from the meeting. I would not have closed it if the issue was done.
Manu Sporny: +1 To closing issues quickly, we don't want issues standing out there for a long time.
Matt Stone: If we get to the point where an issue in github can be closed, I'd like to. We have a long list of issues already running, some have quite a lot of activity on them and others don't.
Matt Stone: Let's drive towrads getting issues closed.
Manu Sporny: (As long as the issue has been resolved, of course)
Joe Andrieu: I think this action item is closed, I don't think the issue is closed.
Joe Andrieu: The issue still deserves some work
Matt Stone: Ok.
Matt Stone: That's fine, as we see activity on the issue ... in our chair meetings we'll add new action items and discussion topics. That's ok to me.
Joe Andrieu: Ok, great.
Joe Andrieu: There was an action I took last week that I haven't made much progress yet but I just added to the list.
Matt Stone: I'd like to move on through the rest of the agenda, I don't think we'll get through everything today.

Topic: Face to Face Meeting Opportunities

Matt Stone: I sent a note out last week for F2F activities.
Matt Stone: We don't have a F2F scheduled; we're on hold until the WG is created before we can book that. We'll go to this list when the WG is created to see if there's a convenient event we can coordinate with. If you have any others that you can add, that would be great.
Christopher Allen: RWoT on April 19th will be discussing VC implementations. It is a work item at that group. It's not a recommendation as far as an official F2F, but if you're interested in VC and want to meet other implementers it's an important part of the gruop.
Matt Stone: Anyone else planning on going to Paris for that?
Manu Sporny: DB is going.
Adrian Gropper: I'm going
Joe Andrieu: I'll also be there
Jonathan Holt: I'm trying to.
Matt Stone: We'll look for an update on that, sounds like a great opportunity.

Topic: Portable Reputation Kit

Christopher Allen: There are two different things that have emerged that may be related or not. The first has to do with ... it feels that there's two classes of broad classes of assertions. I've run into this multiple times now. The first class of assertion has to do with somebody who has total authority over something. The simple example is twitter as an org has total authority over the fact that I hold `@ChristopherA`, it's theirs. That's different from say, keybase, who says that Christopher has possession of `@ChristopherA`, but we're not the party that has ultimate control of that.
Christopher Allen: This has come up in other cases, there's a company in Paris that will be at RwoT that basically has the right to be able to create VC based on some French databases. They themselves are not the controllers of the data, they are just allowed to say "Yes, this person is associated with this data and we've validated it second hand."
Nathan George: So perhaps the idea of an authority vs a notary?
Christopher Allen: That's one area. The reason I bring up the Portable Reputation Kit is that they ran into something similar. They want these reputation statements and such where various parties could evaluate the evidence in different ways. Someone is making a claim then someone is making an eval of that claim. They separated the assertion from the eval and had the ability to link the evidence. "Here's the proof outside my assertion and where to go for that."
Christopher Allen: I didn't want to solve that problem in that short time. Is this out of scope, is it something I've missed somewhere in the spec or what?
Manu Sporny: Two things, first is to point out how this has parallels with the education use cases. Like, you have orgs that could verify a transcript aren't the ones that issued it. Orgs can verify they checked a driver's license, but they didn't issue it. It's a very important use case and class of use cases that spans a variety of industries.
Manu Sporny: The second point is that the way the current spec tries to address this is that the signer asserting something, based on out of band knowledge you can know if they are the data provider or just a verifier of it. THat's a bad way of doing it and we should be semantically clear about what is being said. From DB's perspective this is very much in scope and if we can have a cross industry way of doing it it would be fantastic.
Jonathan Holt: The challenge is that the self-assert, and you say who is allowed to revoke it, you're setting yourself up for trouble. Within the claim you can validate and say "here's a list of public keys that could revoke this" ... I understand the dilemma, that's just more of a comment than a question.
Adrian Gropper: This is a very important thing to deal with. In the healthcare use case we have the medical society as a well known place to verify a credential. The issue here is that the medical society isn't issuing the license. The medical society doesn't want to assume the liability necessarily because there's a licensed professional involved, the doctor/prescriber that carries all the liability. That's exactly the issue we're talking about here very clearly laid out and I also agree the revocation responsbility has to be factored in. We have this separation where is there a well known place that's the equivalent of a CA in the old world and how do they transfer and not take the responsibility away from the user, in this case the prescriber.
Christopher Allen: Any one have thoughts on the evidence and evaluation side of it?
Matt Stone: Before we jump into that I had a quick question.
Matt Stone: Sounds like we have several use cases that imply or explicitly have this need. In terms of our terminology with issuer/holder/repo/service provider, how does the responsibility fall? Are we talking about a service provider that is working as an agent of the issuer? That is verifying these credentials on behalf of the issuer? How does this fit into our architecture more generically speaking?
Christopher Allen: I've been pondering this for a while, twitter is an easy case to understand. Other examples in OAuth. A party being able to verify that a particular value is ... somebody had possession of something at the time of oauth/or editing at twitter/ at the time of editing a DNS record. Later they can revoke it later if they noticed it has changed. Twitter who is the ultimate authority. There is going to be a lot of stuff in the transition, there will be people like twitter, small companies, governments, there will be people that [missed].
Christopher Allen: I don't know what the right word is ... "first party and second party" claims is the best I've come up with so far.
Jonathan Holt: In Medicine. I can make a self claim that I am licensed in TN and Board Certified by the American Board of Internal Medicine. The TTP, the American Board of Medical Specialties aggregates the certs of daughter boards, but they themselves won't ever revoke a cert, they only point to the source of truth. So the issue is how does the State of TN sign my VC and add the ability to attest that they work with certain TTP the ability to revoke. My point[CUT]
Jonathan Holt: Revocation list needs to be in the signature.
Christopher Allen: Revoking is a different thing. It's not necessarily twitter's public key in the second party ... you're checking to see if the second party has run into any kinds of things.
Matt Stone: Maybe we should take an action item... something that's an explicit use case or a set of requirements that refer to the use cases we've already identified. That requirements doc has been going pretty quickly. Can we get someone to take a requirements+use cases with this idea in mind and suggest a use case or a requirement that would address it?
Jonathan Holt: We have an issue about revocation.
Nathan George: The trouble with having primary vs secondary authorities is that it needs some type of centralized registry or inventory of which entities have such authority which creates an interesting set of governance issues.
Christopher Allen: But it's not just about revocation.
Christopher Allen: Not specific to revocation, it impacts it. It may apply to all use cases.
ACTION: Christopher Allen to introduce Portable Reputation Toolkit use cases (first party vs. second party claims)
Matt Stone: It sounds like it's a blend of endorsement and delegation.
Christopher Allen: Maybe, you could say there's a third category. I directly absolutely control this data and this authority and then there's somebody I've given agency to do so and then there's just somebody that's validated it.
Jonathan Holt: I'd be happy to contribute to the medical cred claims.
Matt Stone: Ok, I think we're out of time.