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Re: C2PA Specifications - First Public Draft

From: Leonard Rosenthol <lrosenth@adobe.com>
Date: Fri, 3 Sep 2021 15:41:15 +0000
To: Steven Rowat <steven_rowat@sunshine.net>, "public-credentials (public-credentials@w3.org)" <public-credentials@w3.org>
Message-ID: <MN2PR02MB6992EE021238914ADDEC8B84CDCF9@MN2PR02MB6992.namprd02.prod.outlook.com>
I have filed an issue in our public-draft repo (https://github.com/c2pa-org/public-draft/issues/21) to take the guidance you have given me here – thanks for this great conversation – and incorporate it into future drafts.


> Perhaps both together can succeed where either one alone would eventually fail.
All in favor of that!

Leonard

From: Steven Rowat <steven_rowat@sunshine.net>
Date: Friday, September 3, 2021 at 11:37 AM
To: Leonard Rosenthol <lrosenth@adobe.com>, public-credentials (public-credentials@w3.org) <public-credentials@w3.org>
Subject: Re: C2PA Specifications - First Public Draft
On 2021-09-02 8:08 pm, Leonard Rosenthol wrote:

I see the confusion.



C2PA is *NOT* trying to give assets identifiers!   C2PA is about providing provenance to an asset – that itself could most certainly be identified via a DID (stored in whatever method a given DID wishes to use).  In that way, they are complementary.



In fact, once could even store the C2PA provenance data of an asset into a DID if you wished as a way to retrieve the info when all you have is the DID…*BUT* we expect that what users have is the asset (e.g. the image or video on Twitter) and not a DID/URL to the asset.



What if the publisher, or author, and each of the assets they produce, are all identified as a linked system of DIDs, so that a user refers back to the DID Document from any asset. Can this somehow be integrated into the C2PA system?



Absolutely!  The Schema.org grammar for a CreativeWork – which is a component of the C2PA manifest – has a pre-defined field called (oddly enough) `identifier` which would be the logical spot for the asset’s DID to be recorded.   You can use additional CreativeWork fields to refer to other referenced/linked works if you wished.

Thank you Leonard. All this helps me understand C2PA much better.



What if Adobe and Microsoft, who are part of C2PA, support it -- and Apple doesn't?



Then we were unsuccessful in defining a standard that achieved the adoption required.

Unfortunately IMO history is generally ominous on this point.

Perhaps it will be useful to C2PA, for this very reason, to increase integration with DIDs. If, as still seems possible now, DIDs start to become used in various ways as identifiers of both assets and actors, then this integration might drive wider adoption of both systems. Perhaps both together can succeed where either one alone would eventually fail.



Steven Rowat
Received on Friday, 3 September 2021 15:41:32 UTC

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