The W3C Credentials Community Group

Meeting Transcriptions and Audio Recordings (2014-today)

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W3C CCG Weekly Teleconference

Transcript for 2023-06-06

Our Robot Overlords are scribing.
Harrison_Tang: Hello everyone to this week's at w3c ccg meeting today we have a last-minute change of agenda a speaker gasps sick I think if they are in California I think you'll know that it's very very cloudy and cold it's like weird Earth June ever so a lot of people got sick but anyway we'll push back the original agenda of open ID of for VCS and.
Harrison_Tang: if I will presentations to our let letter.
Harrison_Tang: And today we'll just talk about the overview of VC jot with our fellow co-chair Mike here Mike will do the presentation and we'll have the discussions great discussions about this but before we start I just want to do a quick reminders on the code of ethics and professional conduct just want make sure that everyone know be respectful.
Harrison_Tang: to each other honestly I.
<mprorock> Also, you aren't muted you may want to mute by default
Harrison_Tang: Disrespectful comments in the past year or a year and a half but just wanna give a quick shout-out to the code of ethics and professional contact reminder all right quick IP notes anyone can participate in these calls.
Harrison_Tang: However all substantive contributions to any ccg work items must be member of the ccg fourth for IP are signed.
Harrison_Tang: And make sure you have the w3c account if you have any questions or encountered any issues just let any of the cultures know.
Harrison_Tang: This meeting are being recorded and the minutes are automatically transcribed we will publish the meeting minutes and audio recordings within the next few days are generally actually we've been pretty good within the next 24 hours but no just sometimes you'll take a few days all right we use DC chat to two speakers you can type in Q Plus 2i yourself to the qq- to read.
Harrison_Tang: move and you can do Q question mark.
Harrison_Tang: Who is Nick you.
Harrison_Tang: All right introductions and reintroductions if you're new to the community or you want to or you have any change of affiliations where you haven't been engaging you want to re-engage feel free to unmute yourself and kind of introduce yourself a little bit.
Harrison_Tang: Okay what about announcement or reminders.
Harrison_Tang: Any announcements working minders my new place.
Manu Sporny: Just a real quick announcement that I sent out to the mailing list we've had a pretty nice big breakthrough regarding some work around data integrity and a non creds V2 let me put this in the chat Channel non-credit V2 and data Integrity as some of you know they're you know there's a there's been.
Manu Sporny: History of us trying to figure out how to get an ankh Reds and some of the work that we do in this community to converge in over the past two weeks Steven Curran and Patrick st. Louis from the digital identity lab of Canada and province of British Columbia were able to demonstrate in on creds V2 working with the w3c data integrity.
Manu Sporny: Even so this is a big deal because.
Manu Sporny: We've been trying to figure out a way to get this stuff to work together for the past six plus years and with this newest kind of demonstration which was also shared with the Anon krenz Community I think last week and a workshop we finally got some sort of conversions so there's a post on the mailing list about this called you know and on creds V2 and data Integrity convergence folks should take a look there that's.
Manu Sporny: Pretty big news and that's of course on the heels of us all.
Manu Sporny: Um sharing the ecdsa selective disclosure the data Integrity selective disclosure scheme the previous week so what we're seeing here is a number of different communities kind of converging using data Integrity as a mechanism to kind of secure verifiable credentials anyway good news that's it thanks.
Harrison_Tang: Thank you thank you Manuel I've been following the thread is a really interesting read so if you haven't been following I would encourage you to read it so thank you any other announcements or reminders.
Harrison_Tang: Any updates to the work items.
Harrison_Tang: All right quick note on the upcoming I'll coming meanings I know that you know people have been talking about they would love to get some speakers to discuss the intersection of AI and identity so if you have any speakers or any people anyone that you think that we would like to invite to have these kind of discussions here just let any of the cultures know and also I think.
Harrison_Tang: to the earlier Monument.
Harrison_Tang: Regards to data Integrity earlier we have a presentation on selected disclosures there's any one that you want us to find invite to hold those discussions please let us know as well alright so let's get to it man agenda so today we have a last-minute change of the agenda and today we're going to talk about VC chart or verifiable credentials Json web token.
Harrison_Tang: said you know the main speaker.
Harrison_Tang: Talk about the presentations on VC charges will be Mike Mike Iraq I don't think he needs any further introductions he's our beloved cultures I think the fact that he was able to it's really nice by the way to have a speaker ready to go at any time so I just want to say thank thank thank you to him for that and I think the table is yours Mike.
Mike Prorock: Yeah thanks Harrison and yeah no definitely if you don't know me I'm just a nerd I'm one of the co-chairs of this group I am firmly taking my co-chair hat off at this point and going to talk about some of the stuff I'm doing is an editor with VC jobs and especially changes things like that that have come about as part of the 2.0 working group so if you have questions over all around VC VC working group etcetera.
Mike Prorock: Brent on the line Christina may or may not be on the line but the chairs are normally in a.
<brentz> _waves_
Mike Prorock: That working group a big part of my focus for that working group has been on the job side and wanted to really kind of talk through some of the things that actually are a little bit of a change from the way at least Johnson 1.1 and things like that were so I'm going to set the stage by saying that in this is once again this is just personal hat here right as an.
Mike Prorock: I'll Mentor or someone.
Mike Prorock: Been you know kind of got pulled into this ecosystem for a variety of reasons one of the things that always kind of bugged me about 1.0 and 1.1 and things related to jobs or other securing mechanisms was it really didn't feel like you were doing these you know kind of the payloads and things like that require either mappings or Transformations and things were weird right and so one of the things that really got hammered out so far and it's been a huge.
Mike Prorock: Huge amount of work.
Mike Prorock: Do you know.
Mike Prorock: Argument sorry friendly conversation between members of the working group to really come to I think consensus around a couple of things one that were specified in the charter for the working group so let's make sure we can secure the core data model and then also how do we represent media types or content types for these items and things like that notably and I'm going to stay away from this side of the topic there are people that could probably dive in really deep on this side I probably.
Mike Prorock: We could as well but.
Mike Prorock: Because it's a little bit contentious still is this question of like if you just want to do jobs with registered claims and you know ISS and sub etcetera you know I think there's still some open discussion just from issues and PRS that are being debated as to whether we're does that stuff live right does that live in the VC jots bag does it live elsewhere if it does live in the VC job spec how do we make sure it's a good compliant VC etcetera and things like that so that some of the.
Mike Prorock: Duff's up a little bit up in the air but what we do have.
Mike Prorock: Now is a.
Mike Prorock: Really good way of securing the core data model and and I wanted to just roll back as a starting place and talk just a bit about what the VCS actually bring us why or why are they interesting night and and what they're really interesting for is providing a good standardized way of exchanging credentials now a lot of times this stuff you know gets thought of in a personal context right your driver's licenses that you know answering.
Mike Prorock: Is like age verification from an identity card right man is the.
Mike Prorock: One that always comes to mind when I think about be seized for a lot of reasons and I know that's a use case he works heavily with their you know from our interactions I actually tend to deal as an implementer with VCS into other areas one is around data and data verification and has this data been tampered with or modified you know in claims about how that information was gathered as well as claims related to supply chain credentialing for.
Mike Prorock: Ettore purposes and these are different cases right you have things.
Mike Prorock: Some of the stuff while you know might be a little different right you might want things like correlation and traceability throughout the chain whereas in personal cases you may not right and that's one of the beautiful things about the three party model that verifiable credentials brings to us right as a specification is that we have these multiple roles that are clearly defined and credentials can pass between intermediaries and be received and still verified right and that's a neat thing.
Mike Prorock: Thing that's a neat trick.
Mike Prorock: Standardized way and it gives us the ability to link back into really solid semantics so that machines can actually have good understanding of the meaning of the data under the hood at a minimum what this is the VC itself mean right in the claims in Avicii itself mean that's a really helpful set of properties and so a lot of the motivation around this work in general rolls back to that three-party model and the ability to go in and support a lot of cool use cases from this.
Mike Prorock: A very strong privacy-preserving you know manner.
Mike Prorock: So with that kind of background I want to take a look at basically what is a VC look like a now if you're in the VC job world and this has been interesting because I've been going through and running some implementations on the traceability side and running bunch of different implementations on different test sets and the different extensions and things like that lately and one of the neat things is that you can do things now like as long as you're setting this head.
Mike Prorock: Order properly.
Mike Prorock: And we'll get into what goes in there and just a little bit the payload is just a normal verifiable credential what you would typically see as a credential right it's the claim set gets passed in and you can literally just rip out from a lot of these vocabularies I'll use Trace abilities and example but obviously there's citizenship and others where you have these well-defined json-ld vocabularies and schemas validation stuff its grip that example out and dump it right in right cool Nifty.
Mike Prorock: Right and what's going on with a jot if you're not familiar.
Mike Prorock: User often called jots the Nerds are want to do we tend to Jumble things together and pronounce them in weird ways especially acronyms and what's going on basically is that there's a conversion and encoding right of the header and the payload as well as ultimately the signature wants its generated into what's called base64 URL so it's just Basics T4 but entirely web safe right it's.
Mike Prorock: He its URL safe so some characters are flipped around.
<orie> base64url (no pad) : )
Mike Prorock: Libraries for this stuff and what that encoding gives use that ability to transmit that information over the wire embedded in a URL Etc right yes no pad or you know and you know let's it lets you kind of pass that stuff around in a safe Manner and know that what you're doing what you're going to get is the same on the other side right that's that's a helpful property right the data Integrity stuff.
Mike Prorock: I think everyone's familiar with but that gets at this.
Mike Prorock: Different way right it runs canonicalization and you get your end quads and you sign those end you know or Hashem Ensign or sign those and quads and that's that's what you're getting right you're getting the signature of transform method this is much more let's take an encoding and sign that encoded version now what goes in the header here right then so they're going to talk about the header of it well a couple of things from a verifiable credential side probably first and foremost and one of the things that I think is unique about the way.
Mike Prorock: He sees leverage jobs as a format for exchanging this information is that the.
Mike Prorock: Right it's a lot of times just pointing back to a did web or something like that it's giving you a way to go identify what is the key material involved with signing or verifying this John the a log we're going to come back to what I think is probably though the most interesting thing is that there's two things involved to New Media types that are coming about and there's there's a little at-risk asterisk here which is that there's double pluses in these.
Mike Prorock: Things so depending on what happens at ietf we may have to adjust the.
Mike Prorock: But it'll be some version of this which is the type is a VC so verifiable credential that is linked data because the core data model is linked data and it's encoded in a job format right so it's in a Json web token.
Mike Prorock: Ha what's interesting also is the cty the content type this tells us that what what do we expect as far as to claim said to me right what do we expect to be in the pale oak right now as you encode it well this gives us a really strong hint here it's a verifiable credential conforming to the VC core data model it's like data because the core data model is like data data model and it's in Json right json-ld is ultimately just.
Mike Prorock: Json at the end of the day and so that can give you some.
Mike Prorock: About what to do with this after you get it out right after you've gone through and verified signatures.
Mike Prorock: Um and assuming Harrison / normal is watching the queue because I can't monitor both chat and otherwise so if you feel like Ewing up just raised hand type Q Plus whatever get it so now let's roll back to that out thing right Alex specifies what is the algorithm Works pectin here right what it what is the actual algorithm for the signing standpoint and this has relation to other things right but things that often times will get confused.
Mike Prorock: So key types for instance or the curve name.
Mike Prorock: And these are not the same thing and the nice thing about a log is that there's a really good reference to where to go to find out what should be in there and I've got this in the handy links section if you're not familiar with it there's this really cool thing that Ayanna gives us which has where do we go through and look for the algorithm location figure out how to go handle this stuff and what RFC it's related to or other spec Etc right.
Mike Prorock: Right you can see interesting things like what about stuff point.
Mike Prorock: You'ii see you know specs so it's a really good set of directions and master list the other thing that I think is important is sometimes you'll hear things like oh well with Jose or comes at a right you got to go in and Implement all the things right well not real to a degree it's important to represent a certain Baseline for compatibility and how to know that if you're going through and double-checking your implementation or things you may or may not want to down profile from.
Mike Prorock: From they actually give you the Jose.
<orie> these IANA assignments are not "all" the algorithms that have ever existed... they are the ones that were worth registering..
Mike Prorock: Idea I think Corey's put the Cozy equivalent in the chat but they'll tell you is this a required algorithm is optimal is it really strongly recommended right recommended plus and also things like don't use this thing it's prohibited it's bad for whatever reason right in fact we just last couple ietf's who went through and push some of this stuff through where it's like Yep this is a thing that's out there you really don't want to use it outside of very odd.
<orie> sometimes its good to register things, specifically to prohibit them.
Mike Prorock: You know scenarios that are well understood.
Mike Prorock: Um so with that I think the other thing that's worth noting is the fact that this does set up you know some other other goodies right any of the other John stuff that you're familiar with or want to leverage you know x5c for example right if you want to tie stuff back into hey that I want to make sure you're going in verifying a certificate channels right with this and stuff like that so it sets up some of those abilities there.
Mike Prorock: So what goes.
Mike Prorock: Well it's a b c right it's straight core data model VC.
Harrison_Tang: Yeah menu many has a question.
Manu Sporny: Yeah Mike on the on your last Slide the x5c stuff is there are there any plans to use x Phi C + VC ja door like right any algorithms or anything around that.
Mike Prorock: I don't think we would need to write any additional text there honestly and part of the reason for that is it's already well defined in the RFC and so because that verifications happening as part of like years this container around the sine data and they coding you know we would push back to that original RFC loan that but I could say for sure that there are cases like I'm thinking of regulatory cases especially.
Mike Prorock: Lee where we met in a profile for.
Mike Prorock: Saying hey here's how do we want to go handle this in this very specific case that seems like a really good place I'm thinking a traceability though we probably won't do it there as something where you might want to point out and say hey if you're doing this you want to leverage this x5c property or X5 you and go point back to it does that make sense man.
Manu Sporny: Yeah interesting thanks.
<orie> the juice must be worth the squeeze.
<manu_sporny> ^ yeah, wondering about that.
Mike Prorock: Honestly this is one of the things I like about this is you don't have to reinvent the wheel or go back and revisit things unless there's a real good reason to write you got to kind of ask yourself first foremost like does this thing already exists is it already well defined and is there some reason I would want to down select that behavior because they're often times are right there there are a lot of cases where an RFC might be real broad or things like think about did core right you know they're you wind up with these very broad things in aspect to account for.
Mike Prorock: A lot of use cases that may not be applicable in a case where you need tighter security or verifications.
<manu_sporny> (and other things like -- what if your did:jwk conflicts w/ x5c) -- haven't thought deeply about that, tho.
<dave_longley> also be careful: more ways to make verifiers go do more work
Mike Prorock: Payload well fortunately we've got a data model and a bunch of examples of bunch of vocabularies in this group and everything else so that's what goes in the payload right it's all that that work that were actually doing from more business logic side rather than the structure inside.
Mike Prorock: How do I.
<orie> JWS refers to payload (which is opaque bytes), JWT refers to payload as "claimset" and its content type is KNOWN to be JSON.
Mike Prorock: The stuff if I want to create a VC what do I do here right the you know that's where you get into some interesting stuff here and I think strong benefit from this side which is generally speaking you're going to use in whatever language you like to program it in my case on the lazy so I like to code in Python I also do a lot of machine learning so I'd like to code in Python but I also right.
Mike Prorock: Right go for production code typically or at.
<orie> cool part of using JWS is you can use it to secure content types that are not JSON, like application/nquads.
<dave_longley> (if there are 10 different things you can tell the verifier to go do because they were already "built in", that's 10 different ways to attack)
Mike Prorock: Have people that work for me right to you know and rust and things like that they're better for different different kinds of scenarios but really all you're doing is just calling in like if I'm thinking right off the top of my head you would call into the sign operation right right on your JWT library or jwk library and so in the case of python that's a literally just JW T Dot and Coke right that's it and you pass it in what your encoding.
Mike Prorock: Passing the private key you're signing with you may have to.
<orie> Dave, sounds like you are advocating for profiles.
Mike Prorock: Helga's a separate parameter depending on your implementation sometimes it will read that from the header right depending on what's going on and then it performs the gives you back a nice nice little encoded job just like this over on the right hand side and I rip these examples right from VC John spec by the way also double-check them pretty regular as I think disorient now what about verification well same thing use the built-in libraries you got.
Dave Longley: +1
<orie> They are indeed considered a best practice.
Dave Longley: +1
<orie> but they tend to be application specific.
<orie> or industry specific.
<dave_longley> ensure your off-the-shelf libs can let you "profile down" too
Mike Prorock: Go ahead and once again and I'll use Python since its kind of built into my brain at this point in some areas at least where you go ahead and you say yep I want to decode and it's I've got this thing and you know maybe need to separate the signature maybe not ending on the application and here's the public key that I got now obviously you're going to probably want to put some helper wrappers around the stuff like you know to apply by rules that you're most likely after in a verifiable credentials.
Mike Prorock: I'd like hey maybe I want did resolution on that key ID right and go ahead and get the public key and verify that and add some additional checking.
Mike Prorock: And stuff like that.
<orie> similar to vocabularies.
Mike Prorock: So that's all left up to the implement but the core cryptography side is very separate from the data model side under this world.
Mike Prorock: Now I want to get some security concerns and this stuff to General write this this is pretty broadly deployed stuff in the industry so we've beat it up pretty good we found lots of fun ways to exploit it unfortunately of course sometimes the bad guys find that stuff before you do the normal preface do first and foremost is use good key material good Randomness and protect your private keys right that's same with any kind of cryptography signing etcetera but there are things that are very specific and the the in.
Mike Prorock: Euler the fact that Al is not mandatory because it wasn't thought of that way.
Mike Prorock: As being a mandatory thing and thinking more these private use cases but yachts and that's obviously evolved this is pretty problematic right and so there were lots of things around that and there's lots of good discussion rolling in the ietf around this one of the people advocating for that has just joined the queue so Horry fire away.
Mike Prorock: Yep yeah it's a good call out because there's a it's one of those areas that has definitely been people especially in terms of the authentication world right exchange of credentials a little bit different but it's definitely something there are really good reasons for the way the reason it is designed the way it is in the verifiable credential use case we probably want to be a little are on the safe side right it's not going to hurt us any we're already packing in some extra data.
Mike Prorock: Here other little random things though that I think people don't always think.
Mike Prorock: This has to do with whenever you get some piece of information from anywhere on a network all right you just assume if there's a URI in there that it's probably not trustworthy right now Suma came from a user in an attacker particular and so you can get into things like Kidman out you know manipulation and you know pointers back into sir chains are valid or have weird loops and all sorts of other stuff to try to exploit something and another Library like openness.
Mike Prorock: The cell that might be present on your system so there's just things to be aware of that.
<orie> Another reason to include alg, is that you can integrity protect it, which can improve security characteristics.
Mike Prorock: Normal rules that come up have to be accounted for and so if we think about our case with the kids right we're usually they at least from an implementer side in our case like we're always using dids I think for the hockey material and Discovery you know you've got to have good sanity checking in rules and stuff like that around there right so it's it's one of those things that's important because the header sign right and I think.
Mike Prorock: Orie just is beating me to things I should.
Mike Prorock: Wanted to or not which is that you know you can lock in that out right and what's expected there when you issue a VC so some recommendations when you're thinking about use of ECS and I think some of this stuff is probably going to wind up in either implementation guide or in informative and editorial notes on the specification itself but there's some stuff that typically tends to happen when we're thinking.
Mike Prorock: Going about.
Dave Longley: +1 For profiles and using libraries that let you restrict to what you support, as getting "built in things for free" needs to be audited otherwise
Mike Prorock: See charts Etc which is I think this is a key difference with v CG W when your go through and start to do things like say yep you told me this is json-ld now I want to go ahead and make sure it's json-ld before I do something else and maybe I might rules say that I don't want to accept it if it's not valid probably is a good case in a lot of regulatory scenarios but you're processing that after you verify the signature right and so that's an important thing you eat.
Mike Prorock: You don't trust the data because it came from outside somewhere what you have.
Mike Prorock: Our trust in it right event because we got a little more confidence that the data at least wasn't tweak around with before you received it and maybe you're checking off of a trusted issuers list and things like that right answer questions that come on similarly things like status list checking stuff like that rules for that apply after in the processing and inspection and then acting all the data that you received in the cop more importantly acting all the contents of the data you received don't happen until.
Mike Prorock: I'll after you have verified that the signatures are saying now some questions.
Mike Prorock: What if I don't want to mess with the encoding this thing right I don't need this base64 URL stuff right I just you know I want to fall expanded payload stuff like that right well fortunately the rfc's you know and ietf is given us a good mechanism for this which is you know and I think I don't think this has been set and maybe we will maybe we won't look at this and VC jobs but you know there are very good standardized way to say I want to do a you know JWT with an unencoded payload.
Mike Prorock: Those are the cases where the a you probably better be looking at something if you're not doing in coding some.
<orie> sad part of unencoded payload for JOSE is the header size increase
<orie> COSE is much better about detached payloads.
Mike Prorock: It's reproducible you may want to be looking at things like J CS or some kind of canonicalization prior to signing and stuff like that and you better really defining this stuff in either some kind of profile that or interop specification that lets you know what both sides are and what the transport mechanism is making sure that stuff is not going in there and yes the header size definitely increases or you so Davis e will make you there.
Dave Longley: Yeah just wanted to make an important note here around processing after verification given the the three party model wherein people who are implementing digital wallets should be aware of the fact that they're not always going to have an allow list or something for the issuers that they might trust and so any attacker can create a dead key for example and they will produce you know a valid signature so just just be aware of that fact.
Dave Longley: That a lot of the stuff in the.
<orie> maybe don't supprt "did:key" unrestricted in production
Dave Longley: Anyone can generate a signature that will check out and so that's an important consideration.
<manu_sporny> Orie, did:jwk has the same issue...
<orie> that is kinda like "alg:none", or embedding jwk in header for JWT...
<manu_sporny> it's an aspect of SSI, not any particular key format
Mike Prorock: Yeah 100% and thanks for bringing that up Dave because I think that's something that a lot of people you know here verifiable credentials right assume that that means that this data should be trustworthy or something else right but it's this is the kind of the downside to some of these aspects of things like self Sovereign issuers and stuff like that right we're sure you're leveling the playing field but not going to be appropriate for all cases you should probably take things for what that's worth.
<orie> yeah, same issue for any static public key.
<manu_sporny> yes ^
<dave_longley> digital wallets will never know all the issuers, it doesn't matter if it's did:key, did:jwk, whatever.
<dave_longley> that was just an example :)
Mike Prorock: So some Nifty things that come from this and and this is actually the area that I think most excites me it's not so much VC jobs outside of yes finally we've got like the core data model and I can have good link data that I want to go exploit another ways from a Knowledge Graph standpoint all this other cool stuff you can do with json-ld and you know like data in general you know is the fact that this is really setting a path to an a Very consistent and standardized way using off.
Mike Prorock: The shelf tooling go down this path of how do we really start to look.
<orie> device trust stores are a thing.
<dave_longley> i'm talking about general purpose digital wallets for the VC ecosystem.
<orie> FYI, cose has no reserved tag for "typ"
Mike Prorock: In Seaborn binary right and this stuff gets really important when you're looking at large volumes of data going over the wire this gets especially important as I noted at the bottom there right when we start to need to start to look at things like detached payloads right hey I've got this big old file over here that I'm you know but registering a signature around and stuff like that how do I do this and if you if you're not familiar with cozy and Seaboard stuff like that don't worry like we've actually got as tears we already lined up.
Mike Prorock: Up some of the folks who actually wrote like the descriptor languages and actually I think the guy that wrote Seymour.
<orie> it does have a reserved tag for content_type.
Mike Prorock: Coming in a few weeks to go talk about what is he more we're going to come from and all that kind of fun stuff so if you need a primer on that don't worry we're going to make sure everyone knows where to go for the stuff but cozy in the case of Sabor object signing and encryption as opposed to Jose which is Json signing and encryption the you know the what we get from that is Nifty stuff like that and the example I gave here is where you just take payload right rip it.
Mike Prorock: It over to see boards pretty.
Mike Prorock: Most libraries so like in Python it's just like Seaboard to .load S on a date right you're there right you're in right you've got Seaboard it's just binary now and then you can sign it normal mechanisms using whatever libraries you like for that because they sign one is the example right and that's where wouldn't there's one signature attached to this thing's pretty normal for a lot of these use cases.
Mike Prorock: Is though that are covered by cozy cozy sign in generals a little more loose and have multiple signatures and stuff like that so it's an area worth exploring a big note here something that jots give us that c WT S & Cozy don't really give us right now right in the end this is something that I think the working groups that ietf are kind of hammering out is typ Right content types got a good reserved tags 3 I believe.
Mike Prorock: It's like plug it in but once again going from memory here.
<orie> content type is tag 3, see the other tags...
Mike Prorock: Don't trust me on that verify all right but you can set the content type that I'm expecting it to be good linked data conforming to verifiable credential core data model but this typ side right this is the non-standard side or it could probably rent your ears off about why we need to get that in I actually agree with him but it's going to take some work to get that that side of it covered and it may be covered elsewhere so.
Mike Prorock: Yeah Ted.
Mike Prorock: Tag three and and has to do with binary encoding Etc right how do we tag the stuff.
Mike Prorock: So on that I do want to follow up on some things that make verifiable credentials better and especially things with VC John's right stuff that comes up a lot with data integrity and some values there is like hey you know if terms got added to the context that you're using right if a term got modified you'll know it turned out of you probably won't but if the term got modified write your signature is going to break cool right.
Mike Prorock: But you actually do really want to be.
Mike Prorock: This is on your side just putting that logic in there you know on your implementations cetera but if you've got a remote resource right there are things like s RI and other other specs probably want to be looking at in terms of how do you actually make sure that when you're verifying something that you trusted especially in cases context for you probably shouldn't be calling out to the web to grab that stuff right you should probably be working off of trusted reviewed cache copy how do you know that cache copies one.
Mike Prorock: That got used it issuance time so there is a pull request out on this this is actually.
<orie> > Subresource Integrity (SRI) is a security feature that enables browsers to verify that resources they fetch (for example, from a CDN) are delivered without unexpected manipulation. It works by allowing you to provide a cryptographic hash that a fetched resource must match.
Manu Sporny: +1 To SRI
Mike Prorock: An underlying issue in json-ld that they have noted in the json-ld spec so just be aware of that right this this kind of Integrity aspect of knowing that remote resources are the same as what you're operating on is a big question in especially in general right think about the trade case a lot of times you may have some external thing that you've got a signature of or a hash of that you need to be able to represent in a standardized way something comes up a lot for us and I know this question has come up a lot.
Mike Prorock: A lot in this group has come up in VC working group so there is a PR on that.
Mike Prorock: Is that typically when I'm writing code I want to make sure that the okay what they're a verified this signature right it is from who it says it is the signature checked out all that stuff now I want to know before I even take any steps what is there what are these checks like a form to make sure that the structured data that I got right now actually is what I think is the easy check first righteous check make sure it's valid Json cool could thing to do then probably checked.
Mike Prorock: Make sure is it valid Json Aldis instructor properly Etc but you could probably.
Mike Prorock: Further right and if you've got schemas and things like that especially schemas defining what a VC is schemas to describe the vocabulary that you're specifically using that's a good check and then maybe you can think about operating on the contents of the thing that are in there so these are these are all things you probably want to be layering on since we're asking questions about security and integrity and the validity of data.
Mike Prorock: With that big old collection of helpful links if you've not seen them just starting places to go dig in and I did include it last one right just tell you about the ubiquitous of this kind of thing but like Akamai and that was digging around like and one of the things that I thought was interesting is they had a great old iot example of like yeah I want some tokens and keys to exchange around and stuff like that how do I just do that with Bash.
Mike Prorock: Ash and all that's a salad tools are commonly installed on either mine.
<manu_sporny> haha, was that a dig on Windows.... /how dare you!/ :P
Mike Prorock: You know Linux box or if you're on Windows right inside of whatever their new containerization thing is that I'm sure as a developer you have installed because you really need things like piping and good dueling you know the rest of the Unix ecosystem there so you know the stuff is really built around a lot of prolific widely deployed stuff and a lot of times it's the tools are right there at your disposal to go start to play around so.
<orie> sounds good
<orie> take questions if there are any
Mike Prorock: Going to open it up for questions and I had to I had to get the dig in on Windows the but Tory anything that I missed that you think I probably should have covered the he said sounds good so he's probably doing like three meetings Ximena.
Manu Sporny: I'm curious about the cause a cozy stuff right because he signed and in thoughts there is there is the idea there to kind of follow the same direction that the VC jot stuff is taken which is you know you basically just take the core data model you shove it in a in a you know Seymour object and because he signed one that or are there other further optimizations that you're thinking of like.
Manu Sporny: Yeah compression anyway that's General.
<orie> current plan here:
Mike Prorock: Yeah yeah great great question man you know this is my implementer individual hat on right for me I think a good starting place that you kind of have to do is kind of why you have to do Json in general these days anyways as you got to start with what people know and what they're familiar with and support that as a base case and then get into worrying about optimizations after the fact so if I were to take a pic and we've got this defined.
Mike Prorock: Right um.
Mike Prorock: I will comment on this but if I were to take a pic on preference you rip it right over into Seymour cosine 1 it's a clean starting place that everyone understands that's been I mean especially because the software supplies chain side of things it's had a lot of highs in EN like what problems are we going to run into how do we handle things like counter signatures later witnessing stuff and they said there's lots of cool problems being explored in that space and it's had a lot of really really.
Mike Prorock: Ali good eyes and actually some of them are on this call and there's some of the folks from rat.
Mike Prorock: Bonus call that that's that's what I got there or a do you want to comment specifically I think I did call that out around the cty side and you know content so content type and type but or do you want to comment explicitly your thoughts there.
Mike Prorock: He cute - so I must have said close enough to what he was thinking that I was not totally wrong oh there we go.
Orie Steele: Sorry yeah I clicked the wrong button content type is the type of the payload so you know if you wanted to secure different media types and you wanted to make sure that the registered media type would be well understood you would go to the media types registry which I can share a link and you know a million different known register.
Orie Steele: Third media types.
Orie Steele: And if you really wanted to secure one of those registered media types you would put that registered media type as the content type and then you would put the bites of that payload that is of this content type in the payload and you would secure it and so what you know the verifiable credentials working group has done is its defined a or it's requested or registration right and and so it won't receive its requested.
Orie Steele: Castration for my.
Orie Steele: Until the multiple pluses issue is resolved but you know assuming that that the registration of eye on assignments will accept media type requests with multiple plus signs in the future then you would expect to see VC + LD + Jason in the media types registry assignment from Ayanna and then you could secure that content type with cozy or any other.
Orie Steele: System that.
Orie Steele: It media types and then you know this is where you plug in those values so you know for example JWT it's already in media-type registry but that one is for the typ property that's the type of the token and it's a very confusing thing if you're just getting familiar with this content type is the content type of the payload but typ is that sort of type of the entire toe.
Orie Steele: Okin and if you think about it like that's weird because.
<manu_sporny> good analogy, Orie.
Orie Steele: Type property that's embedded inside of the content which is actually also sort of the way rdf types work where you're looking at the the type property of a verifiable credential and you're seeing it's a permanent resident card but you're embedded or that's a type that's embedded in content.
Mike Prorock: Yeah cool yeah I've already that I think that was well said and I think that nesting of things right is a very common thing we see just in you know comp in general right I've got some piece of data I need to wrap it up somewhere else and then go send it over the wire do some things to it get it back out right Harrison I think you're up on the Queue I could be wrong though.
Harrison_Tang: Yeah actually I have a question to to or we I think earlier we have a lot of Side by Side Bar comments and then or you mentioned something about device trust stores and then also sub resource Integrity like who are those things are they related.
Orie Steele: Oh device trust doors are usually part of your operating system there will be a place where you can install certificates and this is your attackers favorite place to install things because it allows for your operating system to process things that it maybe wouldn't normally have processed and so a common example of this is like when your employer install certificates on.
Orie Steele: Your device that are specific to your.
Orie Steele: And they do that to meet with your employer's you know security policies.
Orie Steele: Or in the another case you know maybe you're a government and your mandating that certain certificates be installed on devices of every citizen who accesses the internet from that government you know within the region that that government is a The Sovereign so these are cases where you know there is a collection of key material or certificates and they're on your device accessible to your operating.
Orie Steele: Item and they can be used to make.
Orie Steele: Decisions that impact your security or privacy and you may not be aware that they're having these impacts if you didn't install the certificate yourself or if you just don't know how certificates work on devices but they are going to be processed and understood by your operating system you know for the most part you will get a warning for a self-signed certificate for web origin unless you install that self.
Orie Steele: Sign certificate.
Orie Steele: Bring system until someone to you know force it to be trusted and that's your operating system trying to protect you self signed certificate you shouldn't trust that but maybe you know better maybe you're a developer and you've got a self-signed certificate for something and you just want it to be accepted and you don't want your operating system to complain to you every time you connect through that then you can install that certificate or you know maybe you're wanting to install a different set of root certificates for.
Orie Steele: Another use case maybe it's an iot use case and you want those certificates to be available.
<keith_kowal> Any thoughts on the Open Badge 3.0 implementation of VC-JWT?
Orie Steele: You know for some reason so that's the the trust stores pieces like operating systems tend to have a place where they put these things and if you want your software to be processed in the same way the operating system would normally process these things like that's where you need to go to install these kinds of resources and the sub resource Integrity stuff I linked to that and that Speck is.
Orie Steele: For a basically it covers.
Orie Steele: The concept of the browser wants to check the Integrity of an external resource so you could imagine you have a web page and you're loading jQuery which is very common JavaScript library that lots of people use so jQuery is also a really great place to put privacy destroying malware because you know that lots of things are going to use it so you might want to check the Integrity of the jQuery bundle before the browser will do.
Orie Steele: Anything with it.
Orie Steele: Then you could put sub resource Integrity check on that and that way if the attacker compromises the jQuery resource server that browser will like automatically not process that script because the resource Integrity check is broken and so it forces the attacker to go to places to compromise instead of just going to a CDN and serves JavaScript resources and compromising them there and then having every web browser.
Orie Steele: Matically served.
Orie Steele: That's loading that particular script tag.
Harrison_Tang: Cool thank you thanks.
<mprorock> a?
Mike Prorock: Awesome I think I see Andreas on what a plus is I can't type yet and dress.
Andres_Uribe: Yeah thanks Mike Super useful to hear this one of the things I was wondering is how do you see the evolution of this and what features specific to include jots DC being used here because most of the things that I've sought where jws instead of dots right like.
Mike Prorock: Yeah exactly it's a good call out you know I think there are things that are worthy of exploring right there you know especially when we think about things with you know the way these work right intermediary Changing Hands Etc well it gives us some flexibility to think about some of the properties that are built into jobs it just using them as is that may be appropriate for like hey this is part of my wire transfer aspects and things.
Mike Prorock: Like that.
Mike Prorock: Are things there but this is really just setting the Baseline this is the minimum and that's why that you know is what's being approached from a standardization standpoint now can you go further yeah hundred percent and that's one of the nice things about it the I think the obvious one that comes to mind is your certificate chaining and checking that stuff right that comes up in a lot of both Regulatory and Enterprise scenarios where not only do you want to know that the public key is from selling.
Mike Prorock: And so right in that there.
<orie> if you secure JSON with a JWS, you have made a JWT... all the fields of a JWT are optional... this is a major reason to use profiles, which you care about the structure of the claimset /payload... the profiles can make the "optional" stuff "mandatory" and this improves interoperability.
Mike Prorock: Happen there but you might need to know some other items about that as far as is it tied back into assert chain as they've been a revocation that's managed centrally elsewhere that you need to check against in addition to maybe the credential status tracking and things like that so so those are all things that I think when we think about exploiting additional properties of jots those are you know those are things there.
Mike Prorock: And yeah I think has.
Mike Prorock: Loaded right it's the this is where profiles or building out like a specification around a specific use case that's where you can then leverage that stuff around that those specific use cases.
Mike Prorock: Does that make sense Andreas.
Andres_Uribe: Yeah yeah yeah it does thanks I guess like yeah it's where he's Point like yeah jwt's are all jws has but.
Mike Prorock: Yeah exactly that's it's one of the nice things about it it's also one of the dance Einsteins at least some open questions of like well do we want to do this well it depends on your scenario right that's the flexibility there II did see I think it was Keith post to the question around open badges in the MVC jobs you know asking like hey would we want to go down this path with open badges or should demonstrate a way of doing it I mean sure obviously we're putting the speck out there there's no.
Mike Prorock: Not too I think one nice thing to think about is when we think about.
Mike Prorock: Ventral side right stripped the fountain drop this right in right so there's really not a lot of lift to go in and say Hey you know I just want to go use VC jot with something that's already got a well-defined model Cole great use that well-defined model and just drop it in and sign it a different different way.
<kerri_lemoie> I think some are already doing this with Open Badges.
Mike Prorock: Any other questions from the group here in or actually I'm going to put Nori on the spot talking about like well-defined model and what happens if you want to go test it with this approach how long did it take you to go test this with the entire traceability vocab or.
Orie Steele: What do you mean like do you mean like if you have a library that supports standard signature algorithms how hard is it to sign arbitrary Jason.
<dave_longley> Maybe some of the drawbacks / what is lost if you take that approach would be good to hear about.
<dave_longley> For example, can you still express your open badge on a website that can be processed by a search engine?
Orie Steele: Yeah so I mean it's pretty easy different libraries are going to you know have different apis for the standards so you might find that you know it's a python Library might use the Builder interface scheme Library might have like a lot of functional interfaces for producing signatures go and rust they're going to expose different apis for performing a standard cryptographic operations.
Orie Steele: Operation the good news is that most.
Orie Steele: Libraries will attempt to support standard cryptography wherever possible because it's what gives them interoperability so you know for example the web crypto API supports es 256 but to implement es 256 in web crypto it's awkward you have to like experience web crypto which isn't really all that fun but the signatures you get out on the other side of that or standard compliant es 256.
Orie Steele: Others you have to do some work too.
Orie Steele: From web crypto but you know you might use an off-the-shelf Hosey Library it's going to produce es 256 Jason Webb signatures like in a much faster and easier sort of developer experience and you know in general if you're signing content of a known type you're going to have a really easy time because a lot of the standards and cryptography been built around the idea of I'm going to protect the content type and then I'm going to.
Orie Steele: To protect the payload of that type and.
Orie Steele: Fire can check the signature after reviewing the header and then a verifier can process the payload according to the content type and that's a safe API because you don't accidentally start processing content that an attacker had mutated and so most standard Json web signature libraries when you're processing Jason Webb signature that's a Json web token they will only give you decoded Jason if the signature checks and it will just give you an.
Orie Steele: Error otherwise.
Orie Steele: So you'll be looking at base 64 encoded stuff until you've done your security check and you can decode That Base 64 and flow your foot off if you want that's always an option in cryptography but it's important to sort of think about the standards are one layer of Defense they apis that you build for those standards are another layer of defense and you want to sort of use both of those layers wherever possible.
Orie Steele: That's it.
Harrison_Tang: Cool thanks Horry any other comments we have.
Mike Prorock: I was muted and talking I wanted to comment quickly on something I saw flyby in the chat and I think David Longley brought up a really good comment which is in a specifically I think in relation to open badges like hey what about embedding stuff and a web page for you know to make sure it gets picked up by search engine etcetera right that that is a case where doing things like thinking about having the unencoded side or a you know paired up and.
Mike Prorock: ODed on encoded as useful.
Mike Prorock: Good example of something that's getting adoption today like hey I want to verify this thing is what it says it is and is it rolled out and it's a piece of media I found on the web that's getting picked up by search engines cetera is actually kind of combat of I want to say at this point now you know BBC New York Times entail Adobe others writer playing in this I use the content authenticity side and what's interesting about that and I think there's a lot of correlations back into open badges in some ways right I've got.
Mike Prorock: Some piece of thing that I need to make sure is actually authentic Etc.
Mike Prorock: Handled with embedded Seaboard right and in a way that's very in line with the direction that I think John's 2.0 are you know we're going BC job 2.0 is going so that's just something to bear in mind like when you're thinking about exposing this content exposing content that might be on the web that you then need to verify you know you're not necessarily doing that embedded proof side the way you would be doing otherwise you might be externalizing it may be taking the payload and keeping it on coded.
Mike Prorock: You know Pearl.
Mike Prorock: Etcetera so those are cases that you just need to have in mind there.
<orie> maybe "vc+ld+cbor" will be a registered media type eventually
<manu_sporny> one day :P
Harrison_Tang: All right thanks Mike I've been where a time so just wanted to give a quick preview of what's coming so next week we'll have a discussion around Bitcoins or you know the ID method and then we after that we'll have people from velocity Network talking about know they are Davis thing and then the week after that we have filled when we talking about you know kind of give you an overview of the book on learning digital identity.
Harrison_Tang: yeah and earlier Mike mention about.
Harrison_Tang: One of the co-authors of Sabor talking about concise binary object representation on July 11th so so a lot of cool things coming up feel free make sure that you can join our discussions and then also share these events with your friends and people who might be interested to learn more.
Harrison_Tang: all right.
<manu_sporny> also great job on the presentation MikeP and Orie -- nice save! :)
Harrison_Tang: Have a good one.