Re: Supply Chain Cryptographic Event Logs (was Re: [PROPOSED WORK ITEM] CEL DID Method (did:cel))

A BOL is a 2-party contract between a consignee and a shipper. It can be easily represented as a VC with a 2 x proof proof-set. Once the shipment is consigned, it doesn't change.
Reference: https://www.maersk.com/support/faqs/two-purposes-does-a-bill-of-lading-serve


If you want to track delivery status and/or delivery confirmation, those are different documents (different VCs, typically single party).



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________________________________
From: steve capell <steve.capell@gmail.com>
Sent: Tuesday, January 20, 2026 12:14:19 AM
To: Manu Sporny <msporny@digitalbazaar.com>
Cc: W3C Credentials CG <public-credentials@w3.org>
Subject: Re: Supply Chain Cryptographic Event Logs (was Re: [PROPOSED WORK ITEM] CEL DID Method (did:cel))

Hi Manu,

Thanks for this assessment.  We could be thinking the same thing.

I didn’t mean that the did:cel would contain the entire bill of lading.  Assumed that would be a VC.  I assumed that the issuer of the VC is the original carrier.  The subject of the vc is the consignment identified by a did:cel.  And so the transfer of control is achieved by transferring the underlying did:cel consignment ID to a new controller (aka title owner).  So verification is “yes it’s a valid BoL and issued by a known and trusted ocean carrier, I see that the Consignment id is also represented as a did:cel, now who currently controls that did:cel because that are also the current title holder”.   Is that more or less what you were thinking or am I off track?

Steve Capell
UN/CEFACT Vice-Chair
steve.capell@gmail.com
+61 410437854



On 20 Jan 2026, at 9:42 am, Manu Sporny <msporny@digitalbazaar.com> wrote:

On Sat, Jan 17, 2026 at 9:05 PM steve capell <steve.capell@gmail.com> wrote:
Transferrable records.

I'm not sure the core of that flow is a did:cel or a did:webvh use
case -- it could be a VC use case where the bill of lading has a
controller that is set at every step of the journey by the previous
controller... where the changes to each re-issued VC are wrapped up in
a Cryptographic Event Log (CEL). So, you could punt the NFT and
blockchain network to the curb and just depend on raw/dumb
HTTPS-accessible storage to "hold" the latest version of the bill of
lading.

Don't get me wrong, you could model the ocean bill of lading as a DID
Document, where transfer of ownership is done via key rotation or
something like that. That's one of the benefits of Linked Data -- you
can embed graphs of information just about anywhere. That is also one
of the drawbacks -- you have many ways that information can be
modelled and we depend on a body like UN/CEFACT to tell us all how to
do it.

So, this could look something like:

1. Original bill of lading (BOL) is issued by the Shipper. BOL becomes
the first entry in cryptographic event log with Shipper as controller.
2. Shipper transfers cargo to Carrier. Shipper sets Carrier as
controller and digitally signs VC. Updated BOL becomes second entry in
cryptographic event log with Carrier as controller.
3. Shipper shares latest BOL in cryptographic event log with Bank,
bank releases payment to Shipper. Shipper sets Bank as controller and
digitally signs VC. Updated BOL becomes third entry in cryptographic
event log with Bank as controller.

I probably messed something up in the steps there (you are the expert
here, not I), but I hope you get the gist of how it might work with a
cryptographic event log. The DIDs would be the long-term identifiers
for the entities (Shipper, Carrier, Bank, etc.) -- those could be
did:web, did:webvh, did:cel, doesn't matter as long as they meet the
needs of the ecosystem. Digital signatures to "transfer ownership"
would be based on keys associated with each controller's DID.

Long lived assets.

Yes, we are looking at CELs for this, and they'd mirror the sort of
thing going on with BOL above (except simpler -- usually just
buyer-seller transfers are recorded in the CEL over time).

Authoritative issuers.

CELs may or may not play a role here -- you can combine DIDs with VCs
and CELs to get to multiple variations of what you're talking about
that work without the need for a blockchain (since you noted that
blockchain adoption is difficult in the supply chain space).

Either way the market sees us as solving business problems through consensus rather than a bunch of techies arguing about who’s did method is better (no offence intended !).

Yes, agreed.

-- manu

--
Manu Sporny - https://www.linkedin.com/in/manusporny/

Founder/CEO - Digital Bazaar, Inc.
https://www.digitalbazaar.com/