Re: did:cel - a cryptographic event log-based DID Method

Yes, did:scid should be mentioned in this context..

We have done a demonstration where did:scid can use different verifiable 
history formats (webvh, webs) and different ways of finding the log (via 
HTTPS, or DID URL, or Hedera URL, etc.).

There is a DID parameter called "src", which seems to be pretty much the 
equivalent of "storage" in the did:cel specification.

Here are some examples and a working demo:
https://github.com/danubetech/uni-resolver-driver-did-scid?tab=readme-ov-file#example-dids-and-did-urls

And a video with some explanation:
https://www.youtube.com/watch?v=bO5CbSPAS-k

Not sure what to do about the apparent situation that there exist now 
these various different formats for verifiable history logs (webvh, 
webs/KERI, CEL), needs more discussion I guess to see if alignment is 
possible at this stage...

Markus

On 12/23/25 2:01 AM, Stephen Curran wrote:
> It's a reasonable idea.  Since the log defines the verifiable history, 
> independent of discovery, the log can be stored in different places 
> and processed consistently.
>
> The folks at Affinidi/First Person Project that have implemented the 
> did:scid:vh spec have been able to show exactly that is possible -- 
> although it becomes a bit "meta-meta". "did:scid" itself is a called a 
> meta model.
>
> Boiled down, that implementation uses the did:webvh log format for 
> DIDs published in different places -- web servers, databases, 
> blockchains, etc. The DID itself has no discover data in it (just the 
> prefix and the SCID), and the location is determined in other ways 
> that enable retrieval of the Log (e.g. query parameter, known 
> registries, etc.).  Once the Log is retrieved, the same did:webvh 
> rules for the processing of the verifiable history are executed to 
> verify/resolve the DID Doc.
>
> On Sat, Dec 20, 2025 at 6:52 PM Michael Herman (Trusted Digital Web) 
> <mwherman@parallelspace.net> wrote:
>
>     Stephen, I'm wondering if this conversation is beginning to
>     suggest that did:webvh become a DID metamethod? Some of Manu's
>     comments steered me this direction. did:webvh becomes the metaspec
>     for an entire family of methof features.
>
>     Then stakeholders can carve out the specific did:webvh DID method
>     *profile* that meets their specific requirements e.g. the
>     did:webvh CEL DID method profile.
>
>     Food for thought,
>     Michael Herman
>     Decentralized Systems Architect
>     Web 7.0 / TDW AgenticOS™
>
>
>
>     Get Outlook for Android <https://aka.ms/AAb9ysg>
>
>     ------------------------------------------------------------------------
>     *From:* Stephen Curran <swcurran@cloudcompass.ca>
>     *Sent:* Wednesday, December 17, 2025 5:50:48 PM
>     *To:* Patrick St-Louis <patrick.st-louis@opsecid.ca>
>     *Cc:* Filip K <filip26@gmail.com>; Otto Mora <omora@privado.id>;
>     Manu Sporny <msporny@digitalbazaar.com>; W3C Credentials CG
>     <public-credentials@w3.org>
>     *Subject:* Re: did:cel - a cryptographic event log-based DID Method
>
>     Hi all,
>
>     I wanted to add my perspective as an editor of the did:webvh spec
>     on the recent did:cel announcement and this discussion. Given how
>     close the two methods are in design and intent, I’m concerned
>     about the risk of unnecessary fragmentation, and I’d like to share
>     a few technical observations—especially where did:webvh can
>     readily incorporate ideas introduced by did:cel and its perceived
>     shortcomings.
>
>     I've taken a look at the did:cel spec and this email chain and
>     have these thoughts on the differences, focusing on the new
>     features and the "did:webvh" shortcomings from Manu's emails on
>     this chain.
>
>     On the "new" features of did:cel and their relevance to did:webvh
>
>       * The "heartbeat" idea is useful and an easy addition to
>         did:webvh because of the existing "parameters" concept,
>         allowing the DID Controller to commit to a maximum time
>         between Log Entries and defining what a resolver should do it
>         that commitment is not followed. It does require a spec change
>         for the next version but very easy to both spec and implement.
>         I don't think that there are "differing philosophies in play".
>         We just didn't think of that feature, we like it, we'll likely
>         add it.
>       * Making the DNS part of a did:webvh DID optional is a topic we
>         have discussed several times in the did:webvh Working Group
>         and are already considering for the next version.  As the
>         verifiability of a did:webvh starts with the SCID, the DNS
>         portion is not so much a "hard requirement" (as Manu puts it)
>         as for ease of discovery.  We also think that a DID without
>         discovery information is "not as clean as we would like"
>         (again, as Manu puts it), but there are certainly use cases
>         where it would work -- peer DIDs, ecosystems where a DID
>         repository is in a known place (did:plc), and the query
>         parameter approach as used by did:scid and did:cel.
>       * Oblivious witnessing: Super interesting to think about. 
>         did:webvh has deliberately made the technical approaches
>         simple/clear and left governance up to the ecosystems using
>         did:webvh.  Technically, did:webvh supports exactly "oblivious
>         witnessing" as described by the did:cel spec -- the witness
>         generates a proof of the hash of the log entry. That said, we
>         did put in the spec that the witness "must verify the log
>         entry being witnessed", but we can (and will likely) remove
>         that line, as that is a governance -- and we should not
>         dictate that. With that, we have oblivious witnesses.
>
>     So these are all easy changes to the did:webvh spec. Requires a
>     new version, but easily fitting in the design and we definitely
>     appreciate the ideas!
>
>     On some of the comments from Manu earlier in the chain about
>     did:webvh shortcomings:
>
>       * "did:webvh identifiers are not stable". If a did:webvh DID is
>         portable and "moved", it is by definition a new DID, but
>         retains its SCID and verifiable history. This opens new use
>         cases (porting the DIDs reputation when moving DID publishing
>         platforms) and eases the transition when its storage location
>         must change. Portability is thus an optional feature, not a
>         bug.  Counter -- what happens when a did:cel uses the
>         ?storage... form when issuing millions of credentials, and the
>         storage location goes away?
>       * "did:webvh has pre-rotation commitments". That is a feature
>         that did:cel should consider. Easy to specify, optional, and
>         adds security -- if it is wanted/needed.
>       * "did:webvh requires heavier, stateful infrastructure
>         (witnesses, domains, and watchers)".  Leaving domains aside
>         for now, did:webvh does not require that infrastructure -- it
>         is up to the ecosystem using did:webvh. For ecosystems that
>         require external verification, and longevity (decades),
>         did:webvh provides technically simple approaches that enable
>         ecosystems to decide on how to use (or not) those features.
>           o If an ecosystem (such as the Pharma industry) requires
>             that watchers be in place for decades in case the DID
>             Controller goes out of business, did:webvh gives them a
>             method to do so.
>           o If an enterprise wants to apply governance/policy rules
>             about DIDs published by their sub-entities, they can
>             require they witness DID Log Entries before publication
>             (as BC Gov is doing now with did:webvh).
>           o Regarding domains -- did:cel acknowledges that "storage"
>             is necessary--some place to store the DID Doc. That's
>             infrastructure and did:webvh's can be just as light or heavy.
>       * "the use of JSON Lines requires state". This is a benefit -- a
>         DID resolver can choose to trade off state for speed with JSON
>         Lines. With did:cel's structure, there is not such an option
>         -- you have to retrieve/process the entire log.
>           o That said, we're likewise pretty happy with the
>             performance of did:webvh -- here's a benchmark for a 10
>             year-old DID, updated monthly, with multiple witnesses:
>             https://didwebvh.info/latest/faq/Performance/
>       * "did:webvh...fully backwards compatible set of extensions to
>         did:web" -- I'm not sure where that came from. Here is what we
>         did do:
>           o Put no constraints on the DID Doc contents -- the DID
>             Controller can put anything they want in the DIDDoc.  Same
>             as did:web.
>           o Make it so that there is a mechanical transformation to go
>             from the location of a did:web DID Doc to a did:webvh DID
>             Log (literally -- "add an 'l' to the end of the HTTP URL
>             path"). That allows a publisher of a DID to publish both,
>             and a resolver to check to see if a did:web has an
>             equivalent did:webvh that it could use to further verify
>             the DID.
>           o A DID Controller can easily transition to from did:web to
>             did:webvh by publishing a did:webvh and applying the
>             mechanical steps to publish the corresponding did:web in
>             parallel.
>
>     I hope we can get together and discuss these in the future --
>     hopefully in a W3C DID Methods Standardization Working Group.
>
>     On Mon, Dec 15, 2025 at 9:32 AM Patrick St-Louis
>     <patrick.st-louis@opsecid.ca> wrote:
>
>         I didn't want to side track the conversation towards webvh,
>         only pointing out some inaccuracies in the comparisons.
>
>         Myself and I'm sure other webvh folks would be more than happy
>         to clarify some points during a call.
>         This being said I'll try to keep this response brief so we can
>         focus the conversation around did:cel.
>
>         I'd be happy to provide numbers for production deployments but
>         what I think is most relevant
>         is the governance models that were able to be met through
>         technical webvh features.
>         The lessons learned and decision making through
>         implementations are more valuable IMO.
>
>         I'm not sure where the notion that webvh isn't compatible with
>         did:web is coming from.
>         Webvh is a mechanism which can be used to add a verifiable
>         history to a web did (pre-existing or new)
>         by publishing a log file in a location adjacent to the did
>         document, hence the term parallel.
>         Updates to this document will then need to be captured through
>         a new log entry,
>         and no longer exist in a vacuum.
>
>         If this feature isn't clear from the specification (which I
>         believe it to be),
>         it will need to be addressed because this is core to webvh.
>         We would need more information about the "more unified path"
>         you envisioned,
>         and where this is diverging with the current spec.
>
>         For the portability concerns, Brian has answered this.
>         Portability can be disabled at creation.
>
>         This leaves the watchers, which I see as similar to cel
>         storage services.
>         While it's true that a watcher is an additional infrastructure
>         requirement,
>         so are CEL storage services.
>
>         I think a pre-rotation commitment would be an interesting
>         feature for did:cel.
>         Something else I would like for did:cel is to lean in IPv6
>         usage for storage services.
>         IPv6 has fantastic promise and this is a great use case.
>         Most examples of storage services given are reliant on DNS
>         (such as the gh pages).
>         I'm not opposed to DNS, but if non reliance on DNS is one of
>         the core benefits of did:cel,
>         examples should follow suit.
>
>         An additional question:
>         Does did:cel do anything different that the current cel spec?
>         Meaning is there additional
>         stuff that needs to compliment the cel spec to enable this or
>         was the current cel spec sufficient?
>
>         Discovery is another topic that is currently elusive IMO.
>
>         Overall I think the cel spec is valuable and having this as a
>         first tangible use case is great.
>
>         Regards,
>         Patrick
>
>         On Mon, Dec 15, 2025 at 10:21 AM Filip K <filip26@gmail.com>
>         wrote:
>
>             On Sat, Dec 13, 2025 at 11:23 PM Otto Mora
>             <omora@privado.id> wrote:
>
>                 *...*
>                 Could you suggest what would be the economical or
>                 other type of incentives that would motivate an
>                 organization make a witness server available?
>
>
>             Hi,
>             that is the question I am trying to answer as well: who
>             would be motivated to run witness services, ideally at
>             little or no direct cost?
>
>             The combination of the heartbeat mechanism and witness
>             services is the core innovation. For this model to work,
>             there must be a sufficient number of independent witness
>             services available to support a reasonable threshold, e.g.
>             3-to-10, and diversity.
>
>             Totally blind witness services should be inexpensive to
>             operate and carry minimal risk. Identity managers and
>             wallet operators are likely to be the most motivated
>             participants. e.g. “Use our identity manager to gain
>             access to a large and diverse set of witness services
>             (and, on top of that, use our "AI" to select the right set
>             for you ;).”
>
>             Verifiers and infrastructure providers may be less
>             directly motivated, but their participation adds diversity
>             to the ecosystem and makes it function effectively.
>
>             Just loud thoughts,
>             Filip
>             https://www.linkedin.com/in/filipkolarik/
>
>                 I have often wondered how proponents of did:keri and
>                 similar methods like to claim that they do not need to
>                 use a blockchain VDR, but instead they swap out the
>                 blockchain VDR with a network of witnesses that need
>                 to exist and it's not always clear what would motivate
>                 entities or organizations to make such infrastructure
>                 available. In public blockchains it is a bit more
>                 clear to me, because there is an associated
>                 transaction fee that you pay for submitting
>                 transactions to the VDR such that they are recorded.
>
>                 Thank you,
>
>                 Otto Mora
>
>
>                 On Mon, Dec 8, 2025 at 9:57 AM Manu Sporny
>                 <msporny@digitalbazaar.com> wrote:
>
>                     Hi all,
>
>                     The DID Methods WG Charter is going up for a W3C
>                     Member vote soon and
>                     one of the DID Method types it contemplates
>                     standardizing is a fully
>                     decentralized DID Method. The Cryptographic Event
>                     Log[1] was adopted
>                     as a Credentials CG work item earlier this year,
>                     is listed in the new
>                     DID Methods WG charter, and hinted at a DID Method
>                     that was powered by
>                     the technology.
>
>                     This email is to introduce did:cel, a fully
>                     decentralized,
>                     cryptographic event log-based DID Method:
>
>                     https://digitalbazaar.github.io/did-cel-spec/
>
>                     The goals of this DID Method are:
>
>                     Minimal Infrastructure - A single individual with
>                     a file hosting
>                     location can create and control multiple DIDs in a
>                     way that the
>                     identifiers are highly-available and globally
>                     recognized.
>
>                     Near-zero Cost - The cost to create and control
>                     multiple DIDs is not
>                     burdensome to at least 70% of the world's
>                     population, which are the
>                     number of people that have access to the Internet
>                     as of 2025.
>
>                     Censorship and Coercion Resistant - The oblivious
>                     witness and file
>                     storage services used to manage a DID cannot
>                     censor or coerce an
>                     individual or organization to any significant degree.
>
>                     No Centralization - Witness and file storage
>                     services are abundant,
>                     easy to operate at scale, and are easily
>                     interchangeable if they
>                     become non-responsive or compromised.
>
>                     Over the years, there are many of us that have
>                     invested in DLT-based
>                     DID Methods and have not seen their usage grow at
>                     the rate we would
>                     wish. There are a number of reasons for this, but
>                     many of them boil
>                     down to implementation and operational complexity
>                     as well as
>                     significant infrastructure and transaction costs.
>                     The did:cel DID
>                     method focuses on reducing each of those costs as
>                     much as possible.
>
>                     Please take a look at the spec and let us know
>                     what you think. Raise
>                     issues here if you find anything of concern:
>
>                     https://github.com/digitalbazaar/did-cel-spec/issues
>
>                     We are currently looking for support and
>                     co-editors for this work item
>                     in the W3C CCG and will raise an issue to call for
>                     adoption once we
>                     have a week or two of discussion on this mailing
>                     list. If you are
>                     supportive of this work, please let us know via
>                     the mailing list.
>                     Happy to answer questions and concerns in the
>                     meantime. :)
>
>                     -- manu
>
>                     [1] https://w3c-ccg.github.io/cel-spec/
>
>                     -- 
>                     Manu Sporny - https://www.linkedin.com/in/manusporny/
>                     Founder/CEO - Digital Bazaar, Inc.
>                     https://www.digitalbazaar.com/
>
>
>
>     -- 
>
>     Stephen Curran
>     Principal, Cloud Compass Computing, Inc.
>
>
>
>
> -- 
>
> Stephen Curran
> Principal, Cloud Compass Computing, Inc.
>

Received on Saturday, 3 January 2026 06:40:06 UTC