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Re: Selective Disclosure

From: Isaac Patka <isaac@bloom.co>
Date: Fri, 17 May 2019 11:32:09 -0400
Message-ID: <CANt=UL0FtxMDrff9gk030RYNOoAd6ywuFRNgFZPqp3CHBsRbAA@mail.gmail.com>
To: David Chadwick <D.W.Chadwick@kent.ac.uk>
Cc: public-credentials@w3.org, Verifiable Claims Working Group <public-vc-wg@w3.org>
We have a selective disclosure implementation in production which is
similar to version iii outlined above. The spec is available here:
https://github.com/hellobloom/specs/blob/master/attestation-data/Bloom-Merkle-Tree-22facf0b-bedb-4b45-bb7d-edcd57213eb0.md#selective-disclosure-merkle-tree

And an example Verifiable Presentation using the spec is here:
https://github.com/hellobloom/share-kit#example-1

Some of the context fields are still placeholders and we need to update the
subject identifiers to be DIDs instead of just Eth Addresses but we'd love
to get more eyes on the spec and hear your feedback.

Thanks,
Isaac

On Fri, May 17, 2019 at 11:25 AM David Chadwick <D.W.Chadwick@kent.ac.uk>
wrote:

> Its in the ISO draft for electronic driving licenses
>
> David
>
> On 17/05/2019 15:39, Kyle Den Hartog wrote:
> > The third option is something I haven't heard of as an approach to
> > selective disclosure. I like the idea of adding both in as methods of
> > supporting selective disclosure in multiple ways.
> >
> > When writing specs to this do we highlight concerns with particular
> > approaches? Particularly one of the concerns I had with this is that by
> > sharing even a hash, it creates the potential for data to be brute
> > forced. This is easily solved with adding a salt and only providing the
> > salt when revealing the data. Would we want to include something like
> > this to heed potentially less private implementations?
> >
> > *Kyle Den Hartog*
> > Personal Blog <https://kyledenhartog.com>
> >
> >
> > On Fri, May 17, 2019 at 8:00 AM David Chadwick <D.W.Chadwick@kent.ac.uk
> > <mailto:D.W.Chadwick@kent.ac.uk>> wrote:
> >
> >     Dear All
> >
> >     selective disclosure is clearly an important feature of VCs, e.g. for
> >     driving licenses or passports we might only wish to reveal our name
> and
> >     nothing else. There are several potential ways of doing this, viz:
> >
> >     i) use of ZKPs - zero knowledge proof algorithms allow assertions to
> be
> >     made about the VC, without revealing the VC itself
> >     ii) use of atomic credentials - each property of the credential is
> >     issued as a separate VC so that the holder can reveal individual
> >     properties
> >     iii) use of hashes - The VC only contains hashes of each of the
> >     credential subject's properties, and the properties are separately
> held
> >     by the holder. The holder places the to-be-revealed property in the
> >     Verifiable Presentation and the verifier computes its hash and
> compares
> >     it to the appropriate hash in the VC.
> >
> >     Only the former is mentioned in the data model and neither of the
> >     latter, whereas the latter 2 are less computationally intensive to
> >     support and might be preferred by implementors. Can we add a section
> on
> >     this to the Implementors Guide
> >
> >     thanks
> >
> >     David
> >
> >
> >
> >
> >
> >
>
>
Received on Friday, 17 May 2019 15:36:10 UTC

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