Verification method controller property when working with intermediate DID document representations

[wip-abramson]

A DID method I am working on (did:btc1) supports a method-id that is an encoding of an intermediate DID document representation. E.g. did:btc:<intermediateDocHash>.

In these cases, what value should I put in the controller property of the intermediate representations verificationMethods?

The controller property is a required field for verificationMethod. I believe this can be a relative URL, but I am not sure what is the appropriate relative URL in this case. Is it just empty quotes? Or is it #id? Or something else.

Alternatively, I could populate the controller properties of the verificationMethods in the intermediate DID document representation after generating the DID just as I do with the id field. But ideally there is a relative URL solution I can use.

[peacekeeper]

It cannot be a relative URL.

See: https://www.w3.org/TR/did-core/#verification-methods

The value of the controller property MUST be a string that conforms to the rules in 3.1 DID Syntax.

So it should be the same DID as in the top-level id field.

[wip-abramson]

Interesting, so the pattern should be.

1. Construct the intermediate DID document (Without the DID identifier)
2. Generate the DID identifier
3. Fill in necessary fields with the DID:

• didDoc.id = did
• didDoc.verificationMethods[n].controller = did (for all n verificationMethods)

I guess you probably should also check if a verificationMethod already has a controller before setting it aswell. Since people could create intermediate DID documents with controllers for verificationMethods that are intentionally not the DID of the document.