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Re: Verifiable Claims Telecon Minutes for 2016-01-08

From: Gregg Kellogg <gregg@greggkellogg.com>
Date: Mon, 8 Feb 2016 22:18:46 -0800
Cc: Web Payments IG <public-webpayments-ig@w3.org>, Credentials CG <public-credentials@w3.org>
Message-Id: <47CD19A5-2721-403C-9C2F-656BB7BE8DBF@greggkellogg.com>
To: msporny@digitalbazaar.com
Regrets for tomorrow's VCTF meeting. I may be able to pop in partway through. 

Gregg Kellogg
Sent from my iPhone

> On Jan 8, 2016, at 10:30 AM, msporny@digitalbazaar.com wrote:
> Thanks to Dave Longley for scribing this week! The minutes
> for this week's Verifiable Claims telecon are now available:
> http://w3c.github.io/vctf/meetings/2016-01-08/
> Full text of the discussion follows for W3C archival purposes.
> Audio from the meeting is available as well (link provided below).
> ----------------------------------------------------------------
> Verifiable Claims Telecon Minutes for 2016-01-08
> Agenda:
>  https://lists.w3.org/Archives/Public/public-webpayments-ig/2016Jan/0016.html
> Topics:
>  1. Verifiable Claims Problem Statement
>  2. Anti-Fraud / Anti-Abuse
>  3. Revocation / Status Checking
>  4. Slow Evolution of Agent-Centric Protocols
>  5. Trust and Semantics
> Organizer:
>  Manu Sporny
> Scribe:
>  Dave Longley
> Present:
>  Dave Longley, Manu Sporny, Brad Hill, Brian Sletten, David Ezell, 
>  Eric Korb, Matt Collier, David I. Lehn
> Audio:
>  http://w3c.github.io/vctf/meetings/2016-01-08/audio.ogg
> Dave Longley is scribing.
> Manu Sporny:  Brad Hill has been a Security Engineer at PayPal, 
>  the FIDO Alliance, and is now at Facebook. He is also the 
>  co-Chair of the Web Application Security Working Group at W3C. He 
>  is here as an individual and is NOT representing WebApp Sec or 
>  his company in any capacity.
> Manu Sporny:  We'd like to talk with you today about the 
>  Verifiable Claims Task Force proposal and your thoughts, the 
>  conversation will be driven by you, whatever you want to talk 
>  about, we'd like to hear about. If there are any key questions we 
>  think were missed we can go over at the end.
> Brad Hill:  I've put down a lot of my thoughts here: 
>  https://docs.google.com/document/d/1aFAPObWUKEiSvPVqh9w1e6_L3iH4T08FQbJIOOlCvzU/edit# 
>  [scribe assist by Manu Sporny]
> Brad Hill:  Sounds good. I've put down some of my thoughts in a 
>  Google doc, I've seen it's gotten a lot of readers and comments, 
>  it's as good of a way to start as any.
> Manu Sporny:  Ok, let's go through the doc first then.
> Manu Sporny:  Let's start with the problem statement.
> Topic: Verifiable Claims Problem Statement
> Manu Sporny: http://w3c.github.io/vctf/#problem
> Brad Hill:  I think it's fine. The thing that stood out to me was 
>  the part about not changing service provider without losing 
>  digital identity. A lot of the claims that are interesting have 
>  canonical issuers and I can't port them anyway.
> Brad Hill:  I'm not sure what's imagined by identity portability.
> Brad Hill:  Which of the three parties that you're porting claims 
>  between is unclear.
> Manu Sporny:  That hasn't been proposed as a work item (porting 
>  between issuers). The idea here is that there may be multiple 
>  issuers that say, for example, you've passed the SAT, GRE, or 
>  issuers for driver's license, passports, etc. There would only be 
>  one issuer for many of those like the US government. But for 
>  other things like learning credentials that say you've passed a 
>  particular credential there would be lots of issuers. When we're 
>  talking about portability, we're saying that once a credential 
>  has been issued to an individual or organization, they can choose 
>  where to store that credential. It's the user's choice ... a 
>  digital wallet, a online service, etc. And they can change it.
> Manu Sporny:  Does that clear that up?
> Brad Hill:  Yes.
> Manu Sporny:  Now that that's clear are there any concerns?
> Brad Hill:  There are some questions about trust like is the 
>  trust proprietary or are the technologies, etc? But we can talk 
>  about that later.
> Brad Hill:  Otherwise no.
> Brad Hill:  I think the statement that "there is no standard that 
>  makes it easy for users to assert qualifications to a service 
>  provider" isn't entirely accurate. If you look at SAML for 
>  instance, tech that has been used to transfer claims for rights 
>  and entitlements, used in the education sector, etc. I think it's 
>  been used in a number of places and it would be worth doing some 
>  more tech history around SAML and what that ecosystem looks like 
>  and looked like and if it didn't catch on where it's worth 
>  mentioning as a viable competitor today, the reasons why/why not 
>  would be good. Finding out about systems in Europe and 
>  educational systems would be good. Maybe there isn't a user 
>  centric version of that, but there are service centric ones that 
>  meet that claim.
> Manu Sporny:  Certainly SAML is one of the techs we will do a 
>  deep dive on in the task force.
> Manu Sporny:  There are places where SAML is widely deployed like 
>  you said, they have said that it's not ideally suited for some of 
>  the types of use case they have. So we have talked with very 
>  large orgs in the education sector that have SAML deployed who 
>  have said it's not viable.
> Manu Sporny:  But you're saying do a very deep dive with SAML and 
>  talk about what's not working and the pitfalls, etc.
> Brad Hill:  Yeah.
> Manu Sporny:  Can you think of any other systems that are similar 
>  to SAML in this respect? Cross-industry standard that can express 
>  and exchange claims?
> Brad Hill:  OAuth is similar but if you want to look at the 
>  history of large scale efforts for exchanging this type of info 
>  SAML is the best case to look at.
> Manu Sporny:  So we should rework the problem statement to talk 
>  about SAML.
> Brad Hill:  If I'm a CTO somewhere and I've been around for a 
>  while and I've spent 10s of millions of dollars and I've seen 
>  SAML then I want to see in the problem statement what would make 
>  this new tech more successful than SAML.
> Manu Sporny:  Ok, any other concerns with the problem statement?
> Brad Hill:  No, makes sense.
> Manu Sporny:  Makes sense that it's something we should look into 
>  or do you feel that something positive won't come out of it?
> Brad Hill:  I think that this is something people have wanted for 
>  a long time. It's an obvious way we interact in the real world 
>  and we want to bring it to the digital world and there are 
>  challenges and difficulties in doing that so I've tried to 
>  highlight some of those in the google doc. I'd like to help make 
>  this attempt more successful. It's something to attempt or at 
>  least desire.
> Manu Sporny:  We're very thankful for that document and we're 
>  going to be taking what you wrote and what others wrote in an 
>  output from the task force on things to look out for.
> Manu Sporny:  Ok, let's go with general concerns about 
>  user-centric architectures next.
> Manu Sporny:  Have you had a chance to read some of the 
>  feedback/comments in the google doc you wrote yet?
> Manu Sporny:  If not, we can talk about fraud and abuse section.
> Topic: Anti-Fraud / Anti-Abuse
> Brad Hill:  Hopefully I've said it fairly well, there are other 
>  types of architectures and systems... there are some things where 
>  user agents take some responsibility in this regard, there are 
>  things like smart screen from MS, so on... if a credential gets 
>  stolen out of your device by malware, then your agent is no 
>  longer in the loop to provide that bubble of protection and then 
>  who has visibility into how you deal with that.
> Brad Hill:  In service-centric systems the service always knows 
>  where the credential is being used.
> Brad Hill:  If someone clones my credit card then no one knows 
>  it's being used and that's difficult.
> Brad Hill:  In large companies and at large scale, having a 
>  clearing house that can do analytics, etc. helps with fraud.
> Manu Sporny:  Do you think that a user-centric approach 
>  fundamentally cannot provide the same types of protection? Or can 
>  it be modified, such as a digital signature must be put on a 
>  credential when it's exchanged to lock it down, etc.
> Manu Sporny:  Is it possible to make a user-centric system as 
>  powerful as a service-centric one w/respect to fraud/abuse or can 
>  you do things in a user-centric system to get the same level of 
>  protection?
> Brad Hill:  I think there are ways you can do better than 
>  nothing. You can have a token binding to a key like you 
>  mentioned. I don't know if that impedes on your goals 
>  w/portability. I think there are fundamentally ways that 
>  service-centric archs can provide protection over user-centric. 
>  Large orgs can do that, whereas users may choose to interact with 
>  entities anyway because they don't know better or don't care.
> Brad Hill:  Where are how and what users are allowed to send 
>  credentials to is hard to control.
> Manu Sporny:  Do you think if there was such a user-centric 
>  system and it was successful, would it be a bad thing? Would the 
>  fraud/abuse problem be something that can't be addressed by a 
>  user-centric system? Are you saying even if we put as many 
>  protections as we could, the ecosystem would make us worse off 
>  than we are today because of this architecture? Because there 
>  aren't orgs that are being paternalistic about what you can/can't 
>  do... would it be worse fundamentally?
> Brad Hill:  I think it's not a question of fundamentally worse, 
>  it's just a set of techs that will compete with service-centric 
>  arch, and if you don't do as much of a good job making people be 
>  able to use it with reasonable degrees of trust and assurance 
>  then people won't use it. It will be a competition in the 
>  marketplace.
> Brad Hill:  You should think of the best possible way to do it.
> Brad Hill:  To be successful.
> Manu Sporny:  So the issues are addressable but we have to keep 
>  eyes open and do good analysis.
> Brad Hill:  I can't say, there are a lot of moving parts in the 
>  system regarding complexity of the tech and adoption and what 
>  scenarios you want to support.
> Brad Hill:  I can just say it's something to think about 
>  carefully and trade off against a lot of other concerns.
> Manu Sporny:  Any other thoughts/concerns on fraud/abuse before 
>  moving on?
> Brad Hill:  Nope, I've got things in the doc, but not 
>  comprehensive, only an hour and half to work on, etc.
> Topic: Revocation / Status Checking
> Manu Sporny:  Ok. It seems there's an assumption that long-lived 
>  credentials are hard to check status on.
> Brad Hill:  No, it's just a design decision to think about. You 
>  look at systems where you need to ping back to assurers to ensure 
>  things are still valid, but a loss of privacy. But there are ways 
>  for the user agent to get up to date status information and 
>  sending it along when exchanging, that was mentioned in the 
>  comments as an alternative. You just have to think about these 
>  things and they impact the complexity of the protocol.
> Manu Sporny:  There are four combinations the group has been 
>  looking at. 1. A long-lived identifier as a person w/a long 
>  lived-credential assigned to one of those IDs you own, and you 
>  can crypto-prove you own it. It's like a driver's license that 
>  you can have for multiple years at a time and there's some 
>  revocation list associated with it.
> Manu Sporny:  2. When you get that long-lived credential there's 
>  a way to convert it to a short-lived credential and you can 
>  unbind your long-lived ID from it and you can do this conversion 
>  and hand over a short-lived version of it to give 
>  pseudo-anonymity.
> Manu Sporny:  3. A short-lived identifier with no revocation 
>  list.
> Manu Sporny:  4. Short-lived credential requested on demand, 
>  bound to a channel ID.
> Manu Sporny:  Those are the four mechanisms we are looking at for 
>  how these credentials are used, etc.
> Manu Sporny:  Do you feel that that handles all the cases, with 
>  long-lived credential tied to a long-lived ID, to short-lived, 
>  etc. Do those cover the types the ecosystem might need?
> Brad Hill:  I'm not sure, it's the first time I've heard those 
>  four things ... but can't say if comprehensive at this point.
> Manu Sporny:  Any of those seem crazy?
> Brad Hill:  It makes reasonable sense, I don't know if revocation 
>  list is the right term, it sounds like it applies to more than 
>  one credential. I don't know how to square that with privacy 
>  concerns.
> Manu Sporny:  Yeah, wrong term, there's some revocation 
>  information for your credential and your agent can refresh that 
>  for you.
> Brad Hill:  Stapled-revocation information.
> Manu Sporny:  Ok, we'll use that terminology.
> Manu Sporny:  Anything else on revocation or status checking 
>  you'd want to discuss?
> Brad Hill:  No, mostly ... hmm, mostly I feel like you're asking 
>  for my endorsement. I'm not hear to do that, I've raised some 
>  concerns. I can't endorse that the concerns will all be addressed 
>  because you can't say this will be a 3 or a 4 ... it's big and 
>  complex.
> Manu Sporny:  Yeah, to be clear, we're not looking for 
>  endorsement, we want as much raw input that we can have.
> Manu Sporny:  We want to see if there is anything unreasonable 
>  that you can point to and say "that looks really wrong."
> Manu Sporny:  If we said "we're only doing long-lived IDs and no 
>  revocation" you'd probably say that that sounds bad for a broad 
>  ecosystem.
> Manu Sporny:  That's the kind of feedback we're looking for.
> Brad Hill:  Ok, but I've only looked at the problem statement so 
>  I can't speak, on the fly, to any particular proposals and if 
>  they'll work with large ecosystem concerns, it's more about 
>  balancing all of these things to create a successful ecosystem.
> Topic: Slow Evolution of Agent-Centric Protocols
> Brad Hill:  So, we have the example right now with trying to 
>  transition away from SHA-1 in TLS. And it's a protocol in the 
>  hands of consumers out there on the Web. It's a hard transition 
>  to make. Lots of lots of people still have browsers that use SSL 
>  3.0 only that was obsoleted 12 years ago. Lots of people have 
>  devices that have to be entirely replaced to upgrade. There are 
>  elderly people who have the same computer they've used for years, 
>  still Windows 95 out there. Google is saying "we're using OpenID 
>  Connect and turning the rest off" and Google can do that and a 
>  billion users can get those newer, better features. That's 
>  different from needing to upgrade all the user agents in the 
>  field.
> Brad Hill:  And you have vulnerabilities that last a long time.
> Manu Sporny:  Ok, certainly distributed systems have those 
>  downsides...
> Manu Sporny: http://w3c.github.io/vctf/#design-approaches
> Manu Sporny:  So we've got this list of service-centric qualities 
>  down at the bottom.
> Manu Sporny:  [Lists some qualities]
> Manu Sporny:  Do you: 1. agree that those are downsides to the 
>  service-centric approach? There are downsides, do you think there 
>  are more, do you disagree with what we have?
> Manu Sporny:  What are your thoughts?
> Brad Hill:  I don't know if those qualities are all downsides. I 
>  don't know if silos is correct. I can use any user agent to get 
>  info from facebook, etc.
> Manu Sporny:  That means you can't get a digital driver's license 
>  and put it in facebook and then use it on another driver's 
>  license.
> Manu Sporny:  Does that make sense?
> Brad Hill:  I guess, but you can get your own PGP key and publish 
>  it on facebook or in another place.
> Brad Hill:  Using "agent" here is confusing because it is a 
>  browser or a digital wallet or what?
> Manu Sporny:  Does it make more sense if you take agent out and 
>  make it a service silo?
> Dave Longley:  I was going to ask - are there pieces of 
>  information specific to users, not specific to a particular 
>  service - social relationships, associate them with themselves, 
>  move them to different social networks. [scribe assist by Manu 
>  Sporny]
> Dave Longley:  So, they don't have to define all of those in a 
>  particular service. We're trying to figure out how you can 
>  capture information like that in this problem statement. [scribe 
>  assist by Manu Sporny]
> Brad Hill:  The most common claim is email address - you control 
>  that - Google asserts my work email address to other people - 
>  OpenID Connect sign in. I control that address. Far and away, 
>  most common claim type, canonical issuer of email - email 
>  provider have address with me - lots of issuers are trusted to 
>  make that claim. [scribe assist by Manu Sporny]
> Dave Longley:  That kind of thing we'd like to see more of - so 
>  it's not just email addresses - before you could do something 
>  like that, you have to do that over and over at different 
>  services. [scribe assist by Manu Sporny]
> Dave Longley:  In this case, the issuer shouldn't have to change 
>  - you only need one issuer for that email address - help reduce 
>  fraud, carry those claims with you, use them at other services. 
>  You should be able to do this sort of thing w/ other claims. 
>  [scribe assist by Manu Sporny]
> Dave Longley:  If you have to go back to each issuer, and that's 
>  the only issuer that can supply the claims. You want to collect 
>  those claims - you on a particular issuer - that's the user 
>  centric model. I am someone and I want to collect these claims 
>  from a variety of different issuers. As long as consumers trust 
>  the issuers, the system works nicely. [scribe assist by Manu 
>  Sporny]
> Brad Hill:  I understand that's what you're trying to build - 
>  that doesn't mean service-centric claims are locked into service 
>  providers. I think the hardest/most interesting part is who is 
>  trusted to assert which claims and why. [scribe assist by Manu 
>  Sporny]
> Brad Hill:  That's a problem in service-centric/user-centric 
>  world. [scribe assist by Manu Sporny]
> Dave Longley:  Identity providers (curators) hold on to your 
>  credentials, the way the model works with SAML, the issuer is the 
>  provider, you have to go off to individual services and identify 
>  yourself. Your identity is bound up with each one of these 
>  issuers. Where that identity is either long-lived and 
>  cross-domain or it is specific to a particular site - you can get 
>  credentials issued for that particular site. That's pushing the 
>  user to the center rather than having  [scribe assist by Manu 
>  Sporny]
> Manu Sporny: All these different services having these views of 
>  people.
> Brad Hill:  I get it - the problem statement there, and the 
>  properties should be qualified how service-centric systems work. 
>  Not a question of how user-centric system is supposed to work. 
>  [scribe assist by Manu Sporny]
> Manu Sporny:  Do you want to talk about costs and 
>  trust/semantics?
> Brad Hill:  Trust and Semantics is the most interesting one.
> Topic: Trust and Semantics
> Brad Hill:  There is no simple answer and how you build a 
>  successful ecosystem is hard to do. Given a case study with SAML, 
>  Susan Landow has a good paper on this.
> Brad Hill:  It's a good talk about competing economic issues of 
>  the competing parties and why those other systems haven't taken 
>  off and how we bootstrap that kind of trust and the meaning and 
>  semantics of claims in an arbitrarily extensible system ...
> Brad Hill:  Susan Landau (economic coupled with single sign on) - 
>  on SAML and Federation and economic incentives and why those 
>  systems haven't taken off. [scribe assist by Manu Sporny]
> Brian Sletten: 
>  http://weis2011.econinfosec.org/papers/Economic%20Tussles%20in%20Federated%20Identity%20Management.pdf
> Brad Hill:  [Missed] it was too complicated for people to figure 
>  out the business problems.
> Manu Sporny:  So your statement is more of a "what are the 
>  business models that will make this work?"
> Manu Sporny:  The assertion is "This ecosystem is very costly to 
>  set up, so you need to make sure there is a business model that 
>  supports that cost."
> Manu Sporny:  Is that the gist?
> Brad Hill:  Yeah. If you want it to scale better or be 
>  competitive with service-centric stuff... people use super 
>  providers now. If I want to get people to sign up I can just put 
>  Google, Facebook, etc. on there and I'll get users. "Nobody ever 
>  got fired for going with IBM" idea. If there are a bunch of 
>  providers is that viable, etc? Presumably some of my employers 
>  do... but checking university credentials is a big deal, people 
>  getting fired for falsifying that stuff.
> Manu Sporny:  We're seeing a lot of movement in the education 
>  space and a lot of participants in the work are from that sector. 
>  When people have a degree, did courses, etc. how do we make that 
>  stuff easier to check? We are engaging with that community and 
>  there are business models they are very interested in pursuing 
>  ... and one of the problems we're having is connecting folks like 
>  you that are raising these questions and the orgs that want to 
>  use it. I don't know if it would be helpful for you to talk to 
>  those orgs to see that there are business models there or poke at 
>  them. Figure out if you've done a cost analysis on X or Y.
> Manu Sporny:  Would you be interested in discussing this with the 
>  education industry?
> Brad Hill:  If you guys are doing that, that's great. This is not 
>  my project, I won't engage with other industry partners, they 
>  shouldn't care if my concerns are addressed, you should care.
> Brad Hill:  If you think these are valid concerns you should 
>  think about addressing them. I don't think my endorsement turns 
>  on this one or another.
> Manu Sporny:  Yeah, it helps for us to get this kind of feedback 
>  from you because we can take it to the education industry and 
>  they need to lay out their needs clearly because if you are a 
>  security researcher and not over there you don't see that.
> Manu Sporny:  We want to ask what kind of work product. ... let's 
>  say we go down this user-centric route and there's something to 
>  work on, what do you think that should be. For example if the 
>  group decides this is something we should be doing... do you 
>  think a baby step for coming up with a standard format for 
>  expressing verifiable claims is valuable? Do you think the first 
>  step would be coming up with a data format for that stuff? Don't 
>  talk about protocols, etc.? That's an example of a baby step, or 
>  do you think that coming up with that is somewhat in a vacuum, 
>  without thinking about the protocol would be a mistake? Can you 
>  point to a phase 1 of a WG?
> Brad Hill:  What are the parts that need to be standardized? ... 
>  You want to have portability between agents then that needs to be 
>  standardized. How does the agent work and how does it 
>  communicate? What are the interfaces between the agent and the 
>  issuers and the agent and the consumers for this basic 
>  architecture to succeed.
> Brad Hill:  That's the part that needs to be standardized.
> Manu Sporny:  The pushback we have on that is that it's too bold 
>  and we could start with the format of the claim first and phase 2 
>  we talk about the agent and how it interfaces with the other 
>  parties.
> Manu Sporny:  Should we do that or just go ahead with doing both?
> Brad Hill:  You can approach it either way.
> Brad Hill:  Maybe defining the claims format first, if and what, 
>  the business cases are and what the interest is to drive it going 
>  forward.
> Manu Sporny:  So failing at a basic format means agent protocol 
>  is unlikely.
> Brad Hill:  Well, not that you'd fail but if we can do this is it 
>  interesting enough to get people to use these types of claim, and 
>  would it build support for going further to talk about delivering 
>  them to people, etc.
> Manu Sporny:  We are asking everyone we're interviewing the same 
>  question... if there's something to work on, what is the smartest 
>  thing to work on first?
> Manu Sporny:  If we circulated a charter to do a basic 
>  credential/claim format understanding it will fit in a larger 
>  ecosystem ... do you think W3C membership would respond favorably 
>  or not?
> Brad Hill:  I don't know.
> Manu Sporny:  Ok, that's a helpful answer.
> Manu Sporny:  We don't know how they'd respond either.
> Manu Sporny:  Do you think another standards membership body 
>  would be better qualified to work on this or might as well do it 
>  at W3C?
> Brad Hill:  Certainly, a lot of the community experience with the 
>  service-centric protocol is not in the W3C. OAuth, OpenID, OpenID 
>  Connect, SAML, those have come out of IETF, OASIS Foundation, 
>  etc. To the extent you want to expertise of people in the general 
>  problem space with a different architecture they aren't by and 
>  large super active at W3C. There are people at W3C like Jeff 
>  Hodges. But the W3C might be the most interesting place to do 
>  this in terms of the user agent.
> Brad Hill:  It's probably something that looks a lot like a web 
>  browser, this "wallet" thing -- or an extension or part of it.
> Brad Hill:  I would reach out and establish a liaison with other 
>  groups.
> Manu Sporny:  Yeah, we plan to do that. Part of this is getting 
>  those folks involved, for example Drummond Reed, OpenID, XDI, 
>  OASIS, ... Christopher Allen who co-authored SSL/TLS. We plan to 
>  engage with SAML, LDAP folks as well, etc.
> Manu Sporny:  Is there anything else you wanted to mention or 
>  talk about today, Brad?
> Brad Hill:  I think that's it.
> Manu Sporny:  Thank you so much, I really do appreciate you 
>  taking the time you took, you're really busy.
> Manu Sporny:  I hope we can reach out again if we have more 
>  concerns.
> Brad Hill:  Sure.
Received on Tuesday, 9 February 2016 06:19:18 UTC

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