[proposal] add/specify 'alsoKnownAs' property for ethr-did

[nikolockenvitz]

As already mentioned in decentralized-identity/veramo#260 the DID spec includes the alsoKnownAs property and should be specified and added for ethr-did. Before opening a PR directly, I wanted to propose my ideas here and get some feedback.

update
I would think the easiest is to use the setAttribute/revokeAttribute method of the ethr did registry smart contract. For the attribute name I would think of did/aka or did/alsoKnownAs. Actually I would prefer the latter one because it's more explicit and length doesn't matter as it is padded to 32 bytes anyway. In contrast to public keys and services, the attribute name is completly static and doesn't include any other information, so it's no problem to have a long name. The attribute value could just be the hex-encoded identifier/URI that should be added to the alsoKnownAs property.

Options:

• did/aka
• did/alsoKnownAs (← my suggestion)
• ...

resolve
When resolving the DID document, an array of all these values (that didn't expired yet or have been revoked afterwards) should be returned. One question to be answered is, whether alsoKnownAs should be an empty array or whether this property shouldn't be included in the DID document at all if there are no values. It suggest to do it similar to the others (public key, service, ...) and include the alsoKnownAs property only if the array is not empty.

Options:

• { id: "...", alsoKnownAs: [] }
• { id: "..." } (← my suggestion)
• ...

Your opinion on that / feedback / any other ideas?

Checklist for next steps:

• update ethr did spec
• write tests
• update wrapDidDocument() method of ethr-did-resolver

[nikolockenvitz]

I implemented my proposed changes (see linked pull request). Feedback is welcome.

[rado0x54]

Updated link to spec: https://w3c.github.io/did-core/#also-known-as
Feature is currently at risk.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.