Re: [EXT] Re: LS from GSMA EIG to W3C

Would the GSMA cryptographers be willing to help address the security
issues associated with RDF DataSet Canonicalization, in the context of
multimessage zero knowledge proofs built on top of application/n-quad based
selective disclosure schemes with unlinkability?

If they are eager to help address those concerns, and they see value in
application/n-quads as the base informational unit for unlinkable
credential data models, I think it makes sense for us to comment
specifically on that in whatever the working group puts forward.

I agree with Manu's comment about signature fingerprints, however I think
it's important to acknowledge what is "possible theoretically, and assuming
a lot of work that still has not been done and might not be done in the
lifetime of the charter" vs "what the spec / draft allows today".

The current BBS DataIntegrityProof spec does not enable unlinkability.

That does not mean that BBS can't support it, but if people are signing up
to support the work without understanding that it is still not
delivering on its primary value proposition over ecdsa-sd or sd-jwt...
That's a problem, and we should ensure the record is set straight before
everyone gets disappointed, or the marketing hype of bbs washes away its
maturity and current capabilities.

I say this having seen that happen at least once before for BBS and for
AnonCreds which offered a similar set of capabilities... It can hurt
the mission of digital credentials a lot, when technical capabilities or
performance are oversold.

Let's be clear in the liason statement why GSMA is interested in RDF based
selective disclosure... let's not phrase it as RDF based unlinkability and
selective disclosure, until it can do those things.

If GSMA wants to contribute RDF and crypto experts to help close this gap,
let's get to work!... but it will require RDF expertise... not just crypto
expertise. I hope this clarifies further my previous comments.

OS

On Thu, Sep 14, 2023 at 2:32 AM Manu Sporny <msporny@digitalbazaar.com>
wrote:

> On Wed, Sep 13, 2023 at 6:35 PM Paul Bastian <paul.bastian@posteo.de>
> wrote:
>
>> To give some perspective, you should follow this thread [1] at the eIDAS
>> ARF. It seems GSMA suddenly woke up and realized they need to be part of
>> it. I've given them seven reasons why BBS+ is currently not favored for the
>> PID, but they seem not to understand.
>>
> Hmm, my read on that thread is a bit different. There are a number of
> legitimate criticisms of SD-JWT as applied to the PID and a call for better
> technical solutions. I note that there are individuals from the IETF CFRG,
> not just GSMA (who have deep expertise in cryptography), that are
> criticising SD-JWT and calling for BBS+-based solutions.
>
>
>> So I assume they are privacy advocates at any cost or they might have a
>> hidden agenda.
>>
> Presume good faith; getting an official liaison statement out of GSMA is
> not a trivial thing to do -- it almost certainly went through multiple
> approval processes so we can't just cast the request aside based on a
> presumption of a "hidden agenda". One could say that SD-JWT or ecdsa-sd's
> "hidden agenda" is tracking people using signature fingerprints -- which is
> not conducive to a productive discussion.
>
> -- manu
>
> --
> Manu Sporny - https://www.linkedin.com/in/manusporny/
> Founder/CEO - Digital Bazaar, Inc.
> https://www.digitalbazaar.com/
>


-- 


ORIE STEELE
Chief Technology Officer
www.transmute.industries

<https://transmute.industries>