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Re: RDF Dataset Canonicalization - Formal Proof

From: Tobias Looker <tobias.looker@mattr.global>
Date: Sun, 28 Mar 2021 16:53:14 +1300
Message-ID: <CAJmmfSSKft_mG8miVezY5Gskc4wUWqJ+jKoG8MC1q80nZHd9UA@mail.gmail.com>
To: Christopher Allen <ChristopherA@lifewithalacrity.com>
Cc: Steve Capell <steve.capell@gmail.com>, Adrian Gropper <agropper@healthurl.com>, Alan Karp <alanhkarp@gmail.com>, Drummond Reed <drummond.reed@evernym.com>, Manu Sporny <msporny@digitalbazaar.com>, "W3C Credentials CG (Public List)" <public-credentials@w3.org>
> I’m a big fan of this approach, a form of redaction distinct from zk
forms of selective disclosure.

> There was an attempt to spec one here in the CCG three-four years ago,
but it died on the vine.

I'm also interested in learning more about this approach too, the questions
I had last time were

1. How the salt for each redactable statement would be managed in a way
that would not leak the abstraction that "Linked Data Proofs" sets up. For
example would the attached proof block have to have a long array of salts?
2. Proof sizes, having to have a salt per-statement signed as a part of the
proof would significantly increase the size of the proofs representation.
3. Signature correlation, perhaps not important in this scheme, but I think
the approach would require revealing a fixed signature regardless of which
parts are redacted from the original proof?
4. Performance? Also perhaps a non-issue but if anyone has info/benchmarks
around how the scheme might scale with the size of the data graph signed,
that would be great to look at?

Thanks,
[image: Mattr website] <https://mattr.global>
*Tobias Looker*
Mattr
+64 (0) 27 378 0461
tobias.looker@mattr.global
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<https://www.linkedin.com/company/mattrglobal> [image: Mattr on Twitter]
<https://twitter.com/mattrglobal> [image: Mattr on Github]
<https://github.com/mattrglobal>
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On Sun, Mar 28, 2021 at 3:49 PM Christopher Allen <
ChristopherA@lifewithalacrity.com> wrote:

> On Sat, Mar 27, 2021 at 7:22 PM Steve Capell <steve.capell@gmail.com>
> wrote:
>
>> The Singapore government https://www.openattestation.com/ does this
>> already . Version 3 is W3C VC data model compliant
>>
>> Each element is hashed (with salt I think) and then the hash of the
>> hashed is the document hash that is notarised
>>
>> The main rationale is selective redaction (because the root hash is
>> unchanged when some clear text is hidden). But I suppose it simplifies
>> canonicalisation too...
>>
>
> I’m a big fan of this approach, a form of redaction distinct from zk forms
> of selective disclosure.
>
> There was an attempt to spec one here in the CCG three-four years ago, but
> it died on the vine.
>
> I’d be interested is seeing this spec & implementation. Any links?
>
> — Christopher Allen [via iPhone]
>
>>

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Received on Sunday, 28 March 2021 03:53:39 UTC

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