Demonstration of support of DID-Auth-based Confirmation Method

Hi all,

The VCWG has been working to define Holder Confirmation Method (aka Holder
Binding and the term is being bikeshedded) normatively as a new extension
point in the VCDM 2.0 standard:

https://github.com/w3c/vc-data-model/pull/1054

Since this is going to be a new extension point, there are no extension
specifications for that extension point yet. However, most people use
DID-Auth and PKI-based approaches for Holder Confirmation Methods in
production.

In our community and beyond, a number of specifications, presentations, and
papers refer to DID Auth already.

We know of a number of companies using DID-Auth as a Holder Confirmation
Method in production around VCs. Since there is no formal definition of how
DID-Auth can be used with the VCDM, it would help these companies if we
could formalize a DID Auth-based Holder Confirmation Method in the VCWG
that can be registered in the VC Directory.

The formalization won't cover the DID-Auth protocol, it will only cover how
to encode the DID in the VCDM and to verify the Holder Confirmation Method
based on a received verifiable presentation. The effort will be low.

To progress the work item, we need other companies that are interested in
helping develop the spec within the VC WG, so please raise your hand by
undersigning this letter:

https://docs.google.com/document/d/1Fdof-S7fhMzhzw8saldfIWLn8ybpVLbK4dvFOJYUNIA

Why now? Because at the end of March, we will have a feature freeze, and if
we want to make this work happen, we need your voice now. This will ensure
that we have one Holder Confirmation Method fully defined and registered in
the VC Directory.

Thanks,
Oliver Terbu