- From: Manu Sporny <msporny@digitalbazaar.com>
- Date: Fri, 25 Jul 2025 12:06:01 -0400
- To: Wolf McNally <wolf@wolfmcnally.com>
- Cc: public-credentials@w3.org, Christopher Allen <christophera@lifewithalacrity.com>
On Wed, Jul 23, 2025 at 9:58 PM Wolf McNally <wolf@wolfmcnally.com> wrote: > The deck from that presentation is here: > https://developer.blockchaincommons.com/assets/pdfs/2025-06-provenance-marks.pdf Thank you for the links Wolf, I was finally able to take the time today to look through the deck in detail and think I understand the deltas between CEL and PM. Conceptually, they are very similar and only differ, as far as I can tell, in the following ways: * PM secures the log through forward-commitment of secrets, which makes it much simpler than applying a digital signature. * CEL secures the log through the use of hashes with (in theory optional, but in reality mandatory) digital signatures (both for controller-initiated changes and for witnessing changes). * Thus, PMs are far simpler to implement in this respect and naturally post-quantum secure. * PMs use CBOR as the base data structure, CELs use JSON as the base data structure (with the ability to be translated to YAML or compress down to CBOR). * PM is effectively an opinionated container format, while CEL is an opinionated log format which includes a way to point to data and witness that data. CEL could be built on top of PM... what we'd lose is the ability to express the core log data structures in JSON/YAML. Conceptually, I see significant overlap between CEL, PM, and did:webvh's log format. I still don't have a good handle on C2PA and SCITT's overlap, though note that they differ in the choices for log format, identifiers, and digital signatures as well. > We’re happy to meet with anyone who has questions regarding PM, and we’d certainly be happy to discuss joining forces. At present, it seems like at least the folks working on CEL, PM, and did:webvh should get together to discuss what the opportunities for alignment could be. Each does seem to have a different set of core requirements that went into the design, which is reflected in the technologies selected. Still doing the analysis on C2PA and SCITT... -- manu -- Manu Sporny - https://www.linkedin.com/in/manusporny/ Founder/CEO - Digital Bazaar, Inc. https://www.digitalbazaar.com/
Received on Friday, 25 July 2025 16:06:42 UTC