Re: [arch-d] Proposed IAB program on Wholistic Human-Oriented Discussions on Identity Systems (WHODIS)

[Toerless Eckert <[e-mail]>]

"All difficult crypto problems can be solved with a sufficient number of trusted third parties."

;-))

(not sure who said it first, i heard it first from KennyP).


On Wed, Jun 28, 2023 at 12:13:36PM -0700, Eric Rescorla wrote:
> Yes, I agree that that's what you want, but I don't think it's feasible for
> the reasons I indicated,
> which is that they inevitably end up with some sort of description of your
> identity. Now, it's true
> that a photo isn't as convenient a lookup key as a name, but facial
> recognition is quite powerful
> and getting moreso all the time.
> 
> -Ekr
> 
> 
> On Wed, Jun 28, 2023 at 12:11 PM Glenn Deen <[e-mail]> wrote:
> 
> >
> >
> > On Jun 28, 2023, at 12:06 PM, Eric Rescorla <[e-mail]> wrote:
> >
> > On Wed, Jun 28, 2023 at 11:58 AM Toerless Eckert <[e-mail]> wrote:
> >
> >> +1. Well said.
> >>
> >> IMHO, such credentials solution are not only a challenge butalso an
> >> opportunity for work in IETF. Such as for anonymized authorizations.
> >>
> >> E.g.: Imagine instead of having to show a drivers license when buying
> >> alcohol and
> >> worst case the drivers license is scanned and abused for identity fraud.
> >> Instead you perform
> >> an anonymous authorization that you are over 18 by NFC via your cell
> >> phone.
> >>
> >
> > Now we are getting into the actual work, but I think this is a pretty good
> > example
> > of the limitations of this kind of anonymous credential.
> >
> > For instance, if you are at a bar and you want to purchase alcohol, the
> > person
> > selling it to you needs to know that the person in front of them is old
> > enough.
> > It's not enough to just show them a zero-knowledge proof that your phone
> > has
> > a credential proving that you are over 18 (21 in the US) you actually need
> > to prove
> > that the person in front of them is over age, which means that the proof
> > has to be
> > tied to a biometric (typically a photo). But at that point, the biometric
> > is usable for
> > facial recognition even if your name is hidden.
> >
> > See https://educatedguesswork.org/posts/vaccine-passport-anon/ for some
> > more
> > on this general topic, though more about COVID.
> >
> > The systems where this kind of selective proof technology works better are
> > those
> > where what's being authenticated is some sort of digital operation. For
> > instance,
> > you might want to prove you are a Netflix subscriber but not have Netflix
> > know
> > who is watching what videos. This works because the credential is just tied
> > to your device, not to you personally (yes, I know it's more complicated
> > than this).
> > But it works less well when you have avoid attacks where one person
> > impersonates
> > another.
> >
> > -Ekr
> >
> >
> > In addition to the trusted assertion of age threshold validity, you’d also
> > like to be able keep the challenger from collecting your personal
> > information or any one use the age challenge to collect that you personally
> > were in the bar and what you did there.
> >
> > -glenn
> >

-- 
---
[e-mail]