[MINUTES] W3C CCG Verifiable Credentials for Education Task Force Call - 2022-04-18

Thanks to Our Robot Overlords for scribing this week!

The transcript for the call is now available here:

https://w3c-ccg.github.io/meetings/2022-04-18-vc-education/

Full text of the discussion follows for W3C archival purposes.
Audio of the meeting is available at the following location:

https://w3c-ccg.github.io/meetings/2022-04-18-vc-education/audio.ogg

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VC for Education Task Force Transcript for 2022-04-18

Agenda:
  https://lists.w3.org/Archives/Public/public-vc-edu/2022Apr/0020.html
Topics:
  1. IP Note
  2. Call Notes
  3. Introductions & Reintroductions
  4. Announcements & Reminders
  5. VC Governance
  6. PDFS as VCs with James Chartrand from McMaster University
  7. Credential Display in Wallets Discussion
Organizer:
  Kerri Lemoie
Scribe:
  Our Robot Overlords
Present:
  Kerri Lemoie, James Chartrand, Stuart Freeman, Deb Everhart, 
  Brandon Muramatsu, JeffO Real-IT, Geun-Hyung, Simone Ravaoli, 
  Marty Reed, Dmitri Zagidulin, John Kuo, Andy Miller, Keith, Phil 
  L (P1), Nikos Fotiou, Yashwardhan, Leon, yashwardhan, G, Alan 
  Davies, Colin (LEF), Kayode Ezike, David Chadwick, Jim Goodell, 
  Kaliya, Timothy Summers

Our Robot Overlords are scribing.
Kerri Lemoie:  Hello welcome to the VC edu task force call on 
  Monday April 18th I'm today we are going to be discussing 
  credential display in the wallets including PDFs and also a quick 
  touch base on VC and VC Edu governance.

Topic: IP Note

Kerri Lemoie:  I'm for we get started let's start with the IP 
  note anyone can participate in these calls everyone is welcome 
  however any substitutive contributors to any of the ccg work 
  items including this task force must be done by members of the 
  ccg with full IP our agreement signed in you can learn more about 
  this at this link that I'm going to put in the chat right now.
Kerri Lemoie: https://www.w3.org/community/credentials/join

Topic: Call Notes

Kerri Lemoie:  Hey for call notes these minutes well this isn't 
  that these meetings are recorded an audio recording done for 
  every call as much as we can do this but they're also transcribed 
  by the robot overlords and you will see in the chat the job that 
  they are doing as we speak if you see that there is anything that 
  could be corrected that's being transcribed improperly please do 
  us a favor and.
Kerri Lemoie:  You see it do a.
Kerri Lemoie:  Substitution and the chat and you can do that by 
  typing s /i'm phrased to fix or word and then fix phrase I'll put 
  that in the chat as an example.
Kerri Lemoie: Example: s/phrase to fix/fixed phrase/
Kerri Lemoie:  I'm sure that as I speak robot overlords and I 
  don't always get along well so I'm sure we will see lots of 
  examples of that please note that we do use a cue system and 
  these calls so if you have something to say or question to say 
  please type Q the letter Q & A plus sign farewell adieu to the Q 
  and if you feel as though your kids your mind you can type Q - 
  and I will remove you from the queue by doing.
Kerri Lemoie:   I'm this we will.
Kerri Lemoie:  At the Q and then call on you in order.

Topic: Introductions & Reintroductions

Kerri Lemoie:  Okay why don't we see first is there anyone here 
  who's new to the call or who like to make an introduction of 
  themselves today or anyone who's been in the call for a while and 
  would like to reintroduce themselves or have some news to share 
  Dimitri you're in the cube.
Dmitri Zagidulin:  Hi can you hear me okay.
Dmitri Zagidulin:  So yeah I thought I'd do a quick 
  reintroduction only because one of my hats has changed so I have 
  recently reduced my work with digital bizarre do I'm still in 
  close collaboration with Angela's our team and have stepped up my 
  involvement in virtual reality and augmented reality so I'm still 
  doing the same things verifiable credential.
Dmitri Zagidulin:  Decentralized identifiers Secure Storage just 
  bringing that toolbox to the AR and VR world still also involved 
  in digital credentials Consortium and the learner wallet there 
  that's it.
Kerri Lemoie:  Thanks Dimitri that sounds incredibly exciting 
  that's awesome.
Kerri Lemoie:  Anybody else have would like to make an 
  introduction or update us on your current work.

Topic: Announcements & Reminders

Kerri Lemoie:  So next we have announcements and reminders keep 
  in mind that every Tuesday at noon Eastern is the ccg call and 
  that is always worth checking out if you have time to do so to 
  stay up to date on what is going on overall in this community.
Kerri Lemoie:  I'm also next week is the internet identity 
  workshop and that starts on Tuesday this Tuesday through 
  Wednesday or is this Tuesday Wednesday I think but it's next week 
  and that means that we will not have a call next week so next 
  Monday there will be no VC I'd you call I'll send an email 
  reminder out but I just want to let you know they were going to 
  skip next week because some of us will be at that meeting and 
  we'll be able to do this as well are we traveling that day.
<jeffo_real-it> IIW is  Tues, Wed Thurs - Sodl out apparently.
Kerri Lemoie:  Just check the queue here see if we have.
Kerri Lemoie:  I'm sorry I let sold out incredible thank you.
<jeffo_real-it> 250 cap

Topic: VC Governance

Kerri Lemoie:  So before we get started with James we have Jim 
  chartered in here who's been doing some interesting work on PDFs 
  as we seize I was here from McMaster University and I'm just 
  going to fill us in on that work you may have seen some 
  descriptions of this and the mailing list and we thought it would 
  make a lot of sense to ask him to come tell us and every CH you 
  you know what how they've gone about doing this PDFs is something 
  that open badges has discussed for a long time it also has come 
  up quite a bit in this community.
Kerri Lemoie:   You before there's a whole lot of reasons to use 
  PDFs in education.
<jeffo_real-it> If anyone wants IIW ticket check in any case just 
  in case.
Kerri Lemoie:  I'm there there are well understood format and you 
  know and can be secured and have embedded data in such as James 
  will tell you and then we're going to talk more about a 
  credential display and wallets and then I'm gonna have to meet 
  you just helped lead that discussion to you because he has some 
  things in mind but before we get started if you don't mind I just 
  I wanted to ask you all to take a look.
Kerri Lemoie:   At this mirror board.
Kerri Lemoie: https://miro.com/app/board/uXjVO8bG_9s=/
Kerri Lemoie:  The chat and I will share my screen when one thing 
  that we have been talking about or thinking about a lot is what 
  is governance right what is governance in this space.
Kerri Lemoie:  A lot of misconceptions and a lot of questions and 
  I really hope to be able to push on this topic more at internet 
  at the iaw next week and so I'm hoping that I could do some 
  research with folks in this community before we go to see what 
  kind of assumptions and questions and understandings that you 
  have about about what governance is so although I'm not a huge 
  fan of Mero I feel like this is a good place to do this because.
Kerri Lemoie:   You can bring it whatever you'd like whenever you 
  want if.
Kerri Lemoie:  We need another section other than assumptions and 
  questions go ahead and create that you could do what you want 
  with this board and then we'll take a look at it at the end of 
  the week or early next week and and see what we're learning in 
  here and what you know of questions and assumptions we should be 
  addressing.
Kerri Lemoie:  And before I move on I sort of want to check in to 
  see if anybody would like to talk about that now if they have 
  anyone has any questions about this or any sort of like it's up 
  to some questions you'd like to bring up right now before we even 
  get into our main topic.
Kerri Lemoie:  You I will start an email thread on this later 
  today and then feel free to respond to that and add whatever 
  you'd like to this board also feel free to reach out to me 
  directly if you'd like to just talk about it some more I am I 
  don't have a lot of understanding of what governance is I've seen 
  it implemented in various ways and I've heard of some really 
  interesting ideas for Registries Registries and things of that 
  nature I've also heard a lot of.
Kerri Lemoie:  Fusion between what accreditation is and what VC 
  governance is and so I thought it would be a good idea for us to 
  really gather as many questions that assumptions as we could so 
  we can start tackling this over the next couple of months.
Kerri Lemoie:  Critic you some tea so James like to write you to 
  participate and and present what you have for us I will stop 
  sharing my screen so you can do that like you.

Topic: PDFS as VCs with James Chartrand from McMaster University

Kerri Lemoie:  How you doing James nice to see you.
James Chartrand:  Okay thank you I'm good yeah.
Kerri Lemoie:  One thing you might want to do James's turn off 
  your video because we've been having some problems with memory 
  issues the jitsi and I'd love to record as much of this as 
  possible so.
Kerri Lemoie:  Awesome yes thank you.
James Chartrand:  Yeah I just turned it on for a sec so people 
  can see what I look like here we go sure so share my screen.
James Chartrand:  Sorry I'm looks like I'm having to go through 
  and.
James Chartrand:  So it's I'm going to have to restart but I will 
  be right back.
Kerri Lemoie:  Okay Dimitri while we're waiting for James to come 
  back to you want to sort of approach to subjective credentials 
  displays and wallets.
Dmitri Zagidulin:  Sure yeah so with invisi edu here we've got 
  two pressing problems that we need to solve we've got to pain 
  points one is so we have these verifiable credentials that are 
  going to be displayed in wallets but we also would like.
Dmitri Zagidulin:  To bind them to more traditional display 
  artifacts such as PDFs and that's what James is going to be 
  talking about and then the second one is also on the subject of 
  display slightly different somewhat related we want issuers to be 
  able to specify exactly or at least advised to wallets verifiers 
  and other software how to display the credential because at the 
  moment every single wallet everything would be so.
Dmitri Zagidulin:   A soft fire.
Dmitri Zagidulin:  On in the DC world is some way out now there 
  have been precedents in for example open Badges and and some 
  other VC projects that have used things like embedded images to 
  specify how the credential should be displayed and that's that's 
  the other topic that would like to touch on today but James is 
  back so over to you.
James Chartrand:  Okay so maybe I'll just get a very quick bit of 
  background so this is a project at McMaster University and it's a 
  joint project between the faculty of engineering and the office 
  of the registrar there they got into SSI a couple of years ago 
  and started out with lock certs so kind of one of the precursors 
  to I guess verifiable credentials and we at the time started out 
  with a very.
James Chartrand:   It's a relatively small pilot.
James Chartrand:  Like like 50 students where we issued 
  certificates so not degrees and they were issued to the students 
  as a batch and went into the block search wallet and that's where 
  the student held the certificate and they would share it from 
  there and it was all Json that went very well we then went and 
  decided to do degrees so issued for very small cohort of students 
  maybe 50 students in the faculty of engineering their actual 
  degrees again they.
James Chartrand:   They lived in the block search wallet and the 
  students shared their.
James Chartrand:  That also went very well and then when covid 
  hit the registrar thought and so when covid hit there were a lot 
  of problems Distributing will they were alone all sorts of 
  problems but among them was Distributing the degrees the paper 
  copies of degrees to students so rather than mail out all of the 
  copies the university decided to also offer the option to get the 
  digital copy of the block.
James Chartrand:  Shorts and they open that up to.
James Chartrand:  And remarkably that went very well as well and 
  there was massive uptake it was 80 something percent of students 
  chose to download a copy of their degree everybody was super 
  happy with it blocks Arts was great but at that time as a result 
  of our work we kind of got introduced to the DCC and eventually 
  joined the DCC and from there we're introduced a verifiable 
  credentials and.
James Chartrand:   Centralized identifiers so wanted to move.
James Chartrand:  Our prior blocks our system to verify with 
  pensions and decentralized identifiers we also wanted to move off 
  of the Bitcoin blockchain which is where we've been just where 
  our blocks our system anchored hashes of the credentials and we 
  wanted to move off for a couple of reasons one is gdpr and 
  similar kinds of privacy laws where it seems It's not entirely 
  clear but it seems at times as though even hashes aren't allowed 
  on a blockchain.
James Chartrand:   For us with the degrees it was fine.
James Chartrand:  As the degree information is public information 
  and so the fact that somebody got a degree from McMasters public 
  information and so you know we thought it was decided that that 
  was okay to put that up permanently on the Bitcoin blockchain 
  even even though it was just a hash anyhow also wanted to get off 
  the Bitcoin blockchain because we wanted to move from a batch 
  issuance which is what we're doing with blocks hurts where you 
  know the entire cohort at graduation time so thousand.
James Chartrand:   It's whatever would all get their degrees at 
  once.
James Chartrand:  It was all a Merkel took all the credentials 
  were hashed together into a Merkel and the Merkel was put up on 
  the Bitcoin blockchain and so that made it you know affordable 
  but with Rising transaction costs on blockchains like Bitcoin and 
  fact that we wanted to move to an on-demand issuance system where 
  a student could request and get their credential or degree 
  immediately but if we were to Anchor every one of those on the 
  Bitcoin blockchain.
James Chartrand:   The cost would become likely.
James Chartrand:  Exorbitant so anyhow we wanted to move to 
  verify the credentials decentralized identifiers talked to the 
  registrar thought maybe we should start with a pilot again she 
  suggested this is Melissa pool is the Registrar of McMaster very 
  forward-thinking registrar she suggested that we take a look at 
  letters that the registrar's office issues to students to confirm 
  basically student status in different ways so like the letter 
  that you see up there on the left which control confirms the 
  enrollment details.
James Chartrand:   Or student so these are letters that students 
  use say when they're applying.
James Chartrand:  Job if the letter say says that they've earned 
  their degree they are also used but things like getting a better 
  student bank account freeing up money from your student savings 
  plan or incoming foreign students might use one of these letters 
  when they're applying for a Visa coming into the country.
James Chartrand:  And so we thought great and initially we 
  thought okay we'll just do it the same way will issue Json copies 
  so you know the actual verifiable credential as Json to the 
  student and it will live in a wallet but we in talking to some of 
  the people in the registrar's office realized that just wasn't 
  feasible because these letters are often they pretty much need to 
  be PDFs because of how they're used so.
James Chartrand:   In some cases they're uploaded as.
James Chartrand:  Application process say if you are applying for 
  a Visa and you need to upload a letter confirming your status the 
  system will only take you know an image or a PDF and that's later 
  reviewed by somebody who looks at it so if it had been Json they 
  wouldn't you know it would be nonsensical to them and they 
  wouldn't know what to do with it also sometimes the letters do 
  need to be printed off and handed to somebody like say when a 
  foreign student is riding in the country and the way it works in 
  Canada is you.
James Chartrand:   To process your visa application as you as you 
  step off the airplane.
James Chartrand:  Typically you've got all your papers you know 
  you know folder and you present them to the agent the agent goes 
  through them and reviews from them decides yay or nay so it had 
  to be printable as a paper copy okay so I will take you very 
  quickly through what we've built here this is totally integrated 
  into the Microsoft Azure authentication system on campus and 
  draws data from a back-end PeopleSoft system.
James Chartrand:  Go to this web browser on the right this is 
  where the student would write this again is just a pilot nothing 
  here is in production and the dire warnings there are because 
  rightfully so the registrar is concerned that we don't want 
  anybody to think that this is the system that's being used at 
  McMaster University because then you could imagine scenarios like 
  the student arrived a student arriving at.
James Chartrand:   The border agent of the.
James Chartrand:  Thanks this is what they should thinks that 
  they should be getting a copy of a letter like this with a QR you 
  know and then doesn't accept one without a QR so we're being 
  extra careful not to make anyone think that this is a production 
  system okay yeah so I am here I'm a student I will login.
James Chartrand:  I will request a letter we've got the red star 
  chose four different letters I'll choose confirmation of status 
  so that kicked off a dynamic process in the background it pulls 
  the information from the PeopleSoft system based on the student 
  login ID assembles the PDF letter I'm using I think Jace PDF some 
  kind of JavaScript PDF library to construct it on the Fly insert 
  the information at the same time.
James Chartrand:   I turn the information into.
James Chartrand:  The information into a verifiable credential 
  then into a verifiable presentation then use digital bazaars 
  amazing libraries and be pqr to produce the QR code which I then 
  insert into the PDF which you can see down in the bottom right 
  hand corner of the letter on the left hand side and then return 
  it to the student so it's been downloaded and it's in my 
  downloads there I will show you a and so anyhow it corresponds 
  exactly to the letter that you see on the left here.
James Chartrand:   Now the student can of course take.
James Chartrand:  In email it to somebody that can text message 
  it to somebody they can do whatever they want to with it they can 
  use it as many times as they want to so say they emailed it to me 
  and I'm an employer I can come to this website potential Sonic 
  Master don't see a pretty much have to know in advance that 
  that's the website to which I should go and of course you know 
  I'm sure people rightfully point out here that there are 
  significant problems with this among them are that.
James Chartrand:  Um somebody can fake the verification website 
  but I think that's a general problem in any case assuming I know 
  to go to credentials dot McMaster C.C a I arrived there I choose 
  verify letter I will choose to upload a letter file I choose the 
  file upload and it does its verification on you know the usual 
  way of extracting the BC from the qur an and then doing the 
  verification one kind of interesting thing that happened there is 
  that.
James Chartrand:   What I did what the code did and first of all.
James Chartrand:  That code is running entirely in the web 
  browser there's there was no call back to the server there so it 
  took the it was another JavaScript library that took the PDF 
  opened it up found the QR image inside the PDF and then from 
  there and vote the digital bizarre libraries to extract the VC 
  and run the normal verification okay so that was one kind of 
  verification now I will show you.
James Chartrand:  Printed copy of that letter the sitting on my 
  desk here and I've got my phone hooked up which you can see on 
  the left so I will choose sorry so I'm going to go over here to 
  my phone and it's the same webpage this time I will choose her if 
  I let her again and I will choose scan QR on letter L.
James Chartrand:  And again at 35 exactly the same way and that's 
  it that's it's a super simple system which you know we kind of 
  figures one of the appealing parts of it there's it's dead simple 
  so extremely easy to use some of the challenges that we still 
  face or that I guess we Face our somebody could fake the PDF so 
  they could change some of the details that are within the PDF we 
  kind.
James Chartrand:   Dove deal with that a little.
James Chartrand:  By virtue of the fact that the entire that 
  sorry what's in the BC that's in that QR code contains the 
  critical information that somebody would want to verify so up 
  there on the left and my phone you can see that the down below it 
  says undefined undefined because we're blanking out student 
  information for this and it says is registered at McMaster 
  University is a full-time undergraduate student for the 2028 term 
  so it.
James Chartrand:  I was there what was inside the veritable 
  verifiable credential So what had been signed and you know 
  doesn't show.
James Chartrand:  What was in the PDF nessus I mean it is what's 
  in the PF but it's only what was in the verifiable credentialing 
  confirmed but of course somebody could take the entire PDF and 
  they could put a fake QR code on there and they could provide a 
  fake link and if somebody didn't know to go to the McMaster web 
  page to verify this they would they could very easily be fooled 
  the other thing that we would very much like to do is to start to 
  move.
James Chartrand:   From these letters.
James Chartrand:  Towards something more like a student ID 
  because what we've got here is effectively a student ID I mean it 
  declares the student status but we'd like to take a you know a 
  little step further and start to use it within a wallet like the 
  DCCC wallet as a replacement for the plastic student card in 
  which case we would have to put more information into it and in 
  particular would have to put a student photo into it and at that 
  point.
James Chartrand:   Point the verifiable credential would be.
James Chartrand:  It inside a QR code so this is where I think 
  Dimitri was talking about this a little bit before I got started 
  that we need to start to think about how we can transfer some of 
  that information and one way is maybe to create a kind of 
  ephemeral storage for the full DC and the QR code simply points 
  to that storage and it might be encrypted as well and we passed 
  the key to the verifier so anyhow different kinds of things to 
  start to look at after that and that works out well because I'm 
  done no I.
James Chartrand:   I know it's great you're going to restart it 
  but.
Kerri Lemoie:  Sorry about that I'm not going to start the 
  recording but the transcriber we'll keep going so we'll take it 
  from there thanks.
James Chartrand:  So I am is so any questions that anybody has 
  feel free.
Kerri Lemoie:  Don't see any questions in the queue right now 
  James what are some common questions that you've gotten besides 
  say the QR code issues and the faking of PD PDFs.
Kerri Lemoie:  Or have you already covered those terms of what 
  you told us excuse me.
James Chartrand:  Yeah I think I covered them.
Kerri Lemoie:  Okay I do see Phil Long in the queue so I'm gonna 
  call in fill her.
<yashwardhan> what was the acceptance level of administration?
<keith> I think its a great solution bridging the legacy world 
  with the new digital world.
Kerri Lemoie:  Phil Long you have a give the floor if you can 
  hear us.
Dmitri Zagidulin:  And you're speaking you're muted.
Kerri Lemoie:  Yes okay why don't I call on Marty Marty you have 
  the floor and can come back we'll add them back to the queue.
Marty Reed:  Sure thanks James for this question a couple 
  questions one you know how do you how do you handle revocation 
  or.
Marty Reed:  Or how do you handle versioning or do you is that 
  part of this.
<kerri_lemoie> @yashwardhan - I'll ask your question next
James Chartrand:  The simple answer is it's not part of it the 
  idea with these legs and this is one of the reasons that we chose 
  the letters as kind of a starting point is that they in a sense 
  it expire then the other way where are they.
James Chartrand:  Dated letters and so--.
James Chartrand:  Are no longer useful after a given day so 
  exactly the same way the paper letter would have you know become 
  dated at some point it would be very nice to be able to revoke 
  them and at some point I mean once we have a relocation system in 
  place we would do that and I think at that point it would just 
  work like any other room relocation system for credentials.
Kerri Lemoie:  I feel before you go I'm sorry I'm going to call 
  and I yes I'm going to ask you a short answer question what was 
  the acceptance level of administration.
James Chartrand:  It probably depends with part of the 
  administration the registrar has been incredibly supportive and 
  as I said before is very very forward-thinking I don't know that 
  at other universities registrar's would look at it quite the same 
  way however generally we found that whenever we've shown this to 
  anybody within the administration you know they pretty quickly.
James Chartrand:   We see the benefits of it.
James Chartrand:  And the fact that it's extremely easy to use 
  you get instant verification so I would say it's almost it's 
  almost always the case that we get very very positive feedback 
  from everybody within Administration and I suppose another way of 
  looking at it is they've continued to fund this so that's a 
  pretty good indication that people can see the value of it.
Kerri Lemoie:  Yeah totally alright Phil on you have the floor.
Phil_L_(P1): Yeah apologies can you hear me.
Phil_L_(P1): Okay I was curious that you mentioned that you did 
  internally decided that the need to use sort of existing 
  processes and systems which were PDF depend if you will lead you 
  at this stage to focus on encompassing the verifiable credential 
  as an attachment to the PDF through the QR code but I was 
  wondering is.
Phil_L_(P1): And some sense looking at the rendering of the data 
  in a Json file into something that could be more approximating a 
  fully rendered text document of the sort to PDFs generate as a 
  second phase so that you didn't have to deal with that particular 
  problem that I suspect Dimitri's going to be talking about in 
  later in the session or was there some other reason beyond that 
  other than the not wanting to have to.
Phil_L_(P1):  Icon building a renderer that could make it look 
  pretty for.
James Chartrand:  Yes so initially we thought that we would send 
  these credentials down into our what a digital wallet you know on 
  somebody's phone and then from there they would share it and you 
  know possibly even at that point PDF could be automatically 
  generated from the wallet directly but.
James Chartrand:  Talking to the registrar's office they made it 
  pretty clear that students expect at the moment a PDF and that's 
  almost always how they use this thing and so kind of introducing 
  a wallet into it just overcomplicate it they basically just need 
  to go to this website Download a pdf and then use the PDF if it 
  went into a wallet and then they had to do something from the 
  wallet then they'd have to install the wallet app today.
James Chartrand:   Deal with what was in the wallet so.
James Chartrand:  Only just that for this pilot it's what made 
  the most sense I don't know if that answers your question.
<deb_everhart> but isn't the wallet the way the person controls 
  the record?
James Chartrand:  Yes yes exactly.
Phil_L_(P1): No it does it I think that you're making a very 
  Salient point that there's only so much transition you can make 
  in one jump and at and the bigger problem isn't the technology so 
  in so much as it is the humans that need to be able to feel 
  comfortable with it so I think that's a very good observation 
  thank you.
James Chartrand:  Yeah and it was also very very easy well it was 
  relatively easy to do what we did you know the amazing libraries 
  that digital bizarre provides and they you know the amazing all 
  of the amazing libraries that are in mpm just made it pretty easy 
  to put this thing together and produce something that's actually 
  is immediately usable.
Phil_L_(P1): Got it understood.

Topic: Credential Display in Wallets Discussion

Dmitri Zagidulin:  Thanks so I wanted to respond to Phil's 
  question real quick and then touch on the two points that Marty 
  brought up in terms of your question Phil.
Dmitri Zagidulin:  And why the approach of the PDF rather than 
  being able to embed the display logic in the VC we need both we 
  definitely need both will be talking about the display logic part 
  are shortly but I wanted to highlight that one very important 
  point.
Dmitri Zagidulin:  In a way.
Dmitri Zagidulin:  Producing a PDF or rather binding.
Dmitri Zagidulin:  From a PDF to a credential shortcuts the need 
  for a widely deployed verifier architecture and widely deployed 
  wallet and display architecture because everybody from students 
  too.
Dmitri Zagidulin:  Admission counselors to border guards knows 
  what to do with either PDFs or paper.
Dmitri Zagidulin:  A binding from PDF to credential your you 
  doing sort of progressive layering your you bootstrapping the 
  whole ecosystem oh Natasha real quick on the two points that 
  Marty brought up which is about revocation and about versioning.
Dmitri Zagidulin:  Put lipstick revocation first one thing that I 
  want to highlight is and James touched on this already.
Dmitri Zagidulin:  Separation is an alternative mechanism to 
  versioning so Ian a couple of use cases such as when you have a 
  printed piece of paper or a generated PDF with the student hens 
  over.
Dmitri Zagidulin:  There's no way to do revocation there or if 
  there is it's very crude like putting a footer down down at the 
  bottom that says before accepting this please pick up the phone 
  and call this admission officer to make sure that's still valid 
  right that's that has both privacy implications and is incredibly 
  awkward usability wise so what what that project does is use 
  expiration.
Dmitri Zagidulin:  As a risk mitigation mechanism.
Dmitri Zagidulin:  Same way that replication is used so just 
  wanted to highlight in those cases where you can't do revocation 
  the forget that exploration plays the same.
<kerri_lemoie> I've been working on an LER interoperablity 
  spectrum that is open for input/opinions: 
  https://docs.google.com/document/d/1fwMNbrFL78bVWnZ0BmObFBJnj0uGnFHhR00frybUiTA/edit
Dmitri Zagidulin:  Same method the other thing that I wanted to 
  talk John or a rather ask a clarifying question about is 
  versioning can you tell us a little more what are what do you 
  mean by versioning of of credentials what are some use cases 
  where you would immersion it thanks.
Marty Reed:  That a question for me.
Dmitri Zagidulin:  Yes if you don't mind.
Marty Reed:  Oh yeah sure so well at least in the open credential 
  publisher project we have the idea that transcripts can be issued 
  as verifiable credentials to a student however they may change 
  until the official transcript is released and so we're just 
  thinking about you know versioning.
Marty Reed:   As far.
<john_kuo> Wouldn't that be more of a lineage of revocation and 
  re-issuance?
Marty Reed:  You know as that transcript is updated do we need to 
  replace the existing credential in the wallet do we need to call 
  home and and check for a new version of that credential so into 
  your to your expiration point you know that is one one thing that 
  we've definitely you know looked at.
Marty Reed:  From a from a verification standpoint but that's 
  that's the use cases like the the transcript may be issued to a 
  wallet prior to its being quote unquote official and so in that 
  case you know the desired functionality would be that you know a 
  student would go in look at their credential and it would say hey 
  there's a new version of your credential would you like to 
  download that now.
Marty Reed:   And also.
<dmitri_zagidulin> @John - revocation (of previous versions) 
  might not be needed or appropriate. Because each VC says "at this 
  point in time the following is true"
<dmitri_zagidulin> revoking such a VC says "actually, that VC 
  WASN'T valid at that point in time"
Marty Reed:  For like a teacher teacher license a teacher could 
  have a license with multiple endorsements attached to it that 
  license can be updated over time to add and subtract endorsements 
  and so for professional licenses there's this idea of you know 
  versioning and updating endorsements within the existing 
  credential.
Dmitri Zagidulin:  Got it I think if I can jump the queue real 
  quick so that makes a lot of sense and this sounds like a great 
  topic for a future call the particular question of versioning of 
  long-run credentials such as a medical history employment record 
  or transcript sounds like there's a lot that we want to discuss 
  their.
Dmitri Zagidulin:   I do want to touch on.
Dmitri Zagidulin:  Something that was brought up a question by 
  John and Chad of would you be able to implement versioning as a 
  series of revocation and reissuance and as I pointed out in chat 
  that.
Dmitri Zagidulin:  Visions yes revocation might not be required 
  or even even allowed there because essentially each one of those 
  success of their fiber credentials are snapshots of something 
  that is true at that point in time so much by the way our paper 
  existing paper credentials already have this notion of versioning 
  intuitively such as a bank statement that says this is what we 
  know to be true as of this point in time.
Dmitri Zagidulin:   And then later if.
Dmitri Zagidulin:  If another transaction comes in or if the bank 
  changes something.
Dmitri Zagidulin:  The bank statement looks different but at that 
  point in time that was the views similarly what we're saying with 
  the transcript is at this point in time this was the snapshot and 
  by revoking such a verifiable credential we're essentially saying 
  no that wasn't true of that time right revocation doesn't mean 
  there is a newer version available it means whatever was said 
  then is not true thanks.
Kerri Lemoie:  Thank you Phil you have the floor.
Phil_L_(P1): Thank you I didn't that I think Dimitri is what I 
  was asked about in the versioning system that Marty was 
  describing which is if let's say that a new version is available 
  when the individual opens their wallet to look at a particular 
  credential presumably the credential the wallet has been has been 
  informed that there is a new version available to prompt them to 
  do that if the individual.
Phil_L_(P1):  chose not to I'm.
<marty_reed> On the revocation discussion, I'd love to hear/see 
  any demonstrations of revocation.
Dmitri Zagidulin:  Wicked can you ask that again about the Third.
<marty_reed> currently validation fails if there is a new version 
  in the parent system
Phil_L_(P1): Assuming that you would you're saying that the 
  validation would fail when if they decided to send it to a third 
  party and I just wanted to verify that that's what the intent in 
  the current thinking would be and I guess sure yes that you know 
  the way in which the question was posed to the person holding the 
  wall at the holder is that there's a new version the credential 
  available.
Phil_L_(P1):  I presume you.
Phil_L_(P1): Declined to accept that and just send the existing 
  one you have because it is signed and the like the question is is 
  the presumption that the verifier knows the new exhibit new 
  version is available somehow and therefore would decline 
  verification of the one that was sent to a an employer or some 
  other entity and they then chose to verify try to verify that 
  one.
Kerri Lemoie:  Feels bad I'm question who is that question 
  directed Up.
Phil_L_(P1): Well it to put to full 12 Marty because he talked 
  about it in the ocp but I'm also interested in McMaster case 
  because it sounds like the way it's currently designed the coming 
  back to the Mother Ship so to speak as part of the current 
  designs of the system which would potentially allow them to be 
  able to decline a credential that's been updated and the 
  individual has failed to download the newest version so I just 
  want to verify that too.
Kerri Lemoie:  Okay to be introduced by and holding in the queue 
  for one moment so James and Marty could reply.
Dmitri Zagidulin:  Not at all sure though I do want to reply to 
  that as well.
Kerri Lemoie:  Okay great tips.
James Chartrand:  Um so this is actually something that we've 
  talked about a lot of Ink Master in the context the context of 
  transcripts which is something that we would like to issue this 
  way but my suspicion is that different registrars will have 
  different policies and some might be fine with the kind of the 
  snapshot in time and having a whole load of those circulating 
  around and it's up to whoever's you know verifying the transcript 
  to make sure they've got the latest and greatest.
James Chartrand:   You know as they would.
James Chartrand:  Copies before but I suspect in some cases the 
  registrar would like to have more control over that and make sure 
  that people are getting the latest copy fill you asked if at 
  McMaster we might exert some control at verification time over 
  what's available what's you know considered the latest and 
  greatest and I mean we're not anywhere near there this is the 
  pilot that I showed is pretty much what we've got for this.
James Chartrand:   So we.
James Chartrand:  Have anything beyond that however my guess is 
  that at McMaster.
James Chartrand:  They would want to indicate in some way that a 
  newer version was available so you know so which is another way 
  that it could work is simply that when you come to verify a check 
  is made against a relocation list which might also show not just 
  that something had been you know there might be different levels 
  of relocation or different types of relocations so.
James Chartrand:   You know as Dimitri said you.
James Chartrand:  Means that the credential is no longer valid 
  but you could imagine having a different type that's Ed's the 
  credential is old and there's a newer version so that's a 
  possibility and that I also wanted to just say quickly that yes 
  the verification does come back to McMaster at the moment but 
  only in the sense that you load the web page the actual 
  verification is happening entirely within the web browser within 
  the JavaScript so there's no phone home going on there.
James Chartrand:  We could so any kind of you know check on the 
  validity of a transcript would have to check a re vocation or 
  status list of some sort hopefully that answers your question.
Kerri Lemoie:  Thanks James Marty.
Marty Reed:  So I kind of have a layered answer one is that in 
  the simplest form that verification fails if the issuer decides 
  that that credential is no longer valid so it's a call home to 
  the publishing service that that request that verification now I 
  will say publishing to Sovereign base wallet.
Marty Reed:  Lisa the VC.
Marty Reed:  It's you know again not elegant I'm not known for 
  Elegance but the VC that is issued to the wallet is verifiable 
  and then the payload itself must be verified to the issuer as 
  it's basically a self-published or self issued VC at that point 
  so there's there's two layers to the approach but we're exploring 
  different different methods but that's how it works right now.
<deb_everhart> don't registrars already submit "in progress" 
  student data, such as NSC PDP data reporting and current 
  enrollment requests from students and others, such as the 
  enrollment letter shown?
Kerri Lemoie:  Thanks Marty Dimitri you have the floor.
<deb_everhart> I thought in progress reporting was a common use 
  case
Dmitri Zagidulin:  Thanks so I wanted to add to the discussion 
  that so one I think versioning is a really useful mechanism we 
  should an issue on it on the PC you do you repo and discuss it 
  continue the discussion in depth on a future call I just want to 
  say we already use something like this.
Dmitri Zagidulin:  SeaWorld but in the w3c spec World each draft 
  of the spec says here's the snapshot as of this date but go check 
  over here here's the canonical location of the spec please check 
  to see if it's it's been updated so it might make sense for us to 
  explicitly able to specify this is a version where fiber 
  credential and this is not a version where fiber credential the 
  example of non version verify.
Dmitri Zagidulin:   Credentials for example.
Dmitri Zagidulin:  Here's an age verification credential that 
  somebody is over 21.
Dmitri Zagidulin:  That statement is never going to change the 
  thing that can change is that it could be revoked.
Dmitri Zagidulin:  They used fake ID or whatever however there's 
  no there's not going to be an updated version like they're always 
  going to be over 21 until they die is ETC but that's a different 
  problem so let's open an issue this might be a really useful item 
  for this group to work on.
Kerri Lemoie:  Yeah I agree let's definitely do that does anyone 
  else have any other questions for James or James you have 
  anything else you'd like to add.
James Chartrand:  No I think I'll take a look at this time so I'm 
  good thanks thank you very much for having me.
<phil_l_(p1)> Thank you James. Great work!
Kerri Lemoie:  Now we appreciate it we appreciate it thank you 
  very much doing chairman and hand things over to you so you can 
  talk to us more about the while it display just continue on that 
  discussion.
Dmitri Zagidulin:  Thanks Kerri okay so let's look at thank you 
  again very much James and let's look at late logic short of it 
  is.
<deb_everhart> thank you James!
Kerri Lemoie: +1 Great work!
Dmitri Zagidulin:  Pretty much all the while the projects are up 
  against this this use case this need we need to be able to 
  specify how to display the credential either HUD specify to the 
  pixel or give some suggestions.
Dmitri Zagidulin: https://github.com/w3c-ccg/vc-ed/issues/16
Dmitri Zagidulin:  So this is perfect group to make a 
  recommendation test it out and then make a proposal to Upstream 
  to the ccg and to the verifiable credential working group so I'm 
  going to have issued number 16 on our repo talking about this I 
  add a couple of notes of use cases.
Dmitri Zagidulin:  And so I'd like to ask people disease did he 
  sound reasonable are there.
Dmitri Zagidulin:  Either use cases to this display specifying 
  the display logic that we should add and then we can propose a 
  mechanism in the next calls and get dry so essentially.
Dmitri Zagidulin:  I was not able to pull up the credentials the 
  GitHub issue.
Dmitri Zagidulin:  We need to specify or advise.
Dmitri Zagidulin:  Any sort of VC consuming software how to 
  display that VC.
Dmitri Zagidulin:  We need to support both cases.
Dmitri Zagidulin:  Display logic is completely embedded in the 
  credential or.
Dmitri Zagidulin:  Display logical if somewhere else so you we're 
  linking to an image file or an SVG file or an HTML template 
  somewhere else and we just linking to it from the credential so 
  that when it comes time to display it display software go use 
  that template.
Dmitri Zagidulin:  Obviously when we're embedding the display its 
  Integrity texted by the verifiable credential signature itself.
Dmitri Zagidulin:  Always we're using linking we definitely want 
  to recommend using a digest hash like the anchored resource 
  mechanism.
Dmitri Zagidulin:  We probably should be able to specify the 
  content type of the logic but this link or this embedded logic is 
  PDF and HTML and so on.
<phil_l_(p1)> The anchored resource mechanism has greater 
  applicability to other cases where the size of the "thing" is too 
  big to be included within the credential itself.
Dmitri Zagidulin:  And we should talk about the preference of the 
  credential display being cross-platform right if we're going to 
  we're going to have a template if we're going to have an image 
  you'd be great if we could just specify one and it would work 
  across all platforms mobile desktop and so on but is anybody who 
  works in web design knows that is an almost on achievable dream 
  so given that as a second step we should provide mechanisms.
Dmitri Zagidulin:   That say okay if you're using this.
Dmitri Zagidulin:  Of device use this Logic for using a much more 
  constrained device or a much bigger screen then use this logic 
  fortunately we have prior art for both images and stylesheets in 
  general so lot of HTML world has the technology that says if 
  you're viewing this page on a mobile phone display this way to 
  using it on desktop display this way if you printing it then use 
  this way so we should we should be mindful of that.
Dmitri Zagidulin:   Let's see we got six minutes.
Dmitri Zagidulin:  Love to hear from from the group are there 
  other considerations are there other input requirements for this 
  item.
Dmitri Zagidulin:  Keith go ahead.
Keith: I think maybe I can just dig deeper on display because I 
  think that there can be differences in how well it's display 
  information like what's it take Atticus talk about what kind of 
  information like typically I mean other while it's that I've been 
  involved in you just say things like issue or info like contact 
  support info and then the contents of the VC itself and maybe 
  images so like I've often thought that while it vendors can 
  independently choose how to show that information but I do I mean 
  I totally agree with you.
Keith:  a point that when you want to display things like issuer 
  logo.
Keith: This PDF image then you need ways that wallets you know 
  you don't want to get a crop properly you want to be able to get 
  it sized properly as you can display it properly is that what you 
  mean by this because is that what you mean by display a my 
  capturing it correctly or are you mean other things as well.
Dmitri Zagidulin:  Yes yes no that's it and you're absolutely 
  right that it should be optional.
Keith: And I just like it's up to wallet that I mean that's kind 
  of the beauty of the market is that the the wallet with the best 
  presentation kind of will you know be preferred be preferred by 
  consumers is that rather than some sort of like trying to do 
  static what is it often like display will be one of the key areas 
  of differentiation between wallets how well they do display.
Dmitri Zagidulin:  So you're absolutely right though I do want to 
  say that they're still in need to be able to do this optionally 
  as well James go ahead Joe.
James Chartrand:  Yeah so I mean just one of those needs to do it 
  statically is as I mentioned before one of the things we'd like 
  to do at McMaster is how the student basically.
James Chartrand:  Create the plastic student card inside a wallet 
  and we want to try to make it initially you know as kind of a 
  progressive introduction of this to make it backwards compatible 
  and so therefore we want to include the barcode that's on the 
  plastic student card and possibly also a QR code that somebody 
  could use to similarly scan their student ID so you know it's 
  unlikely that a wallet will know how to.
James Chartrand:   A show those kinds of things or even know to 
  show.
James Chartrand:  So if we could instead just provide a single 
  image that's shown in the wallet or a student card or for a 
  student ID it could be pre you know pretty constructed with the 
  barcode down at the bottom with the student image on it with the 
  logo of the University so basically again recreating the pretty 
  much the same image image that's printed on the plastic card.
Dmitri Zagidulin:  Thanks James you've got a couple minutes left 
  Andy go ahead.
<kaliya> QR codes that are static with VC s dangerous
Andy Miller:  I was wondering your thoughts about the use case of 
  where the VC is actually embedded in the image or PDF that's 
  centrally how open badges that's it now I'm baked badges is a PNG 
  or SVG that has the credential in baked into it using the 
  structured data.
Dmitri Zagidulin:  Great question that that should not should be 
  another item of discussion Phil go ahead.
Phil_L_(P1): Yes I guess what I wanted to say that it seems to me 
  that the hash link approach that you described is actually a 
  broadly applicable to any kind of circumstance where the content 
  of an object is bigger than is reasonable to include in the in 
  the VC itself and so by you know focusing on how you would apply 
  that to different circumstances such as the image on a card and 
  what's presented when it's displayed.
<kaliya> Very dangerous because the can be super easily copied 
  and replyed
Phil_L_(P1):  then is the composite of the polled image from 
  wherever the Third.
<dmitri_zagidulin> @Kaliya - great point
<dmitri_zagidulin> which suggests the need for templating (rather 
  than static image)
Phil_L_(P1): And the rendering of the thing of the way it's done 
  traditionally on the plastic would be indistinguishable from the 
  plastic itself so I think that's the probably the most productive 
  approach and the one I would urge us to consider the biggest 
  problem that that and UND just described is the the same problem 
  of payload size you can do that for small DC's but you can't do 
  it for VCS that contain much like evidence and things like that.
Phil_L_(P1):  that thanks.
Dmitri Zagidulin:  Thank you two minutees left James go ahead.
James Chartrand:  So just about the of the idea of using a hash 
  link for I think there might be privacy concerns there so we 
  might not want to have the student information so and in 
  particular say their photo at a URL you know available add URL we 
  would want to keep an entirely embedded within the credential the 
  so that's just one concern possible concern.
Dmitri Zagidulin:  Thanks James and Kalia.
<phil_l_(p1)> are there privacy concerns there if the destination 
  is itself encrypted?
Kaliya: I'll just say what I said in chat stata QR codes.
Kaliya: And I guess the same is true for barcodes but you know 
  static QR codes with verifiable credentials within them that are 
  signed are very very very dangerous the reason being is that they 
  are entirely copyable and replayable.
<phil_l_(p1)> Excellent point Kaliya
Kaliya: Is this not true of verifiable presentations that are you 
  can't copy and replace because their presentations not the 
  original credential so I have an unfinished but readable paper 
  about this largely written by John Jordan that I think I'll try 
  and send a list I'm sick right now otherwise I'd send it to chat 
  right now but.
Dmitri Zagidulin: https://github.com/w3c-ccg/vc-ed/issues/16
<kerri_lemoie> Thank you!
Dmitri Zagidulin:  Thank you so much Kelly and we hope you feel 
  better soon alright so everyone please let's continue the 
  discussion on issue 16.
Dmitri Zagidulin:  And a quick questions before we adjourn go 
  ahead.
Dmitri Zagidulin:  Thank you everyone.
Kerri Lemoie:  It sounds good nope I would just say and that's 
  good that's take a look at that issue and keep it going we can 
  revisit this in the near future thank you so much James and 
  Dimitri appreciate it all thank you.
<phil_l_(p1)> Thanks!

Received on Thursday, 21 April 2022 17:53:36 UTC