Extension point to support other key attestation formats?

[c2bo]

There is an on-going discussion about supported attestation formats in HAIP (openid/oid4vc-haip#188). There seems to be some consensus to allow other key attestation formats

If I recall correctly the current text in VCI was written in a way that leaves the path open to support other key attestation formats (and defines one JWT based format as a common point for implementation), but how exactly support for such formats is signalled (e.g., issuer metadata) and how the key attestation is transported/attached (e.g., proof type) is currently not defined. Do we need to define the extension point in VCI 1.0 if we want to have text about allowing other key attestation formats in HAIP 1.0?

[c2bo]

Not sure if this in scope for 1.0 or 1.1 depending on the discussion outcome from HAIP I guess?

[jogu]

We have the proof_types_supported metadata already. I think you'd define a new key proof type ("android_attestation" or whatever) and then list it there?

[c2bo]

We have 2 ways to communicate them right now:
a) in the header of the JWT proof
b) in a separate proof

Agreed, that b) would work with a new proof type. For a) we would need to add a new header parameter for JWT i guess? But agreed, we have a clear path with proof types -> if we agree that is sufficient we can close this issue imho. I just want to make sure we are not missing things on that side.