Re: public key in a verifiable credential

> On 1 Apr 2021, at 13:56, Nikos Fotiou <fotiou@aueb.gr> wrote:
> 
> Hi,
> I have a case where I want to include in a VC the public key of the credential subject. I have thought of two approaches:
> 
> a) include in the "id" field of "credentialSubject"  a DID method like did:key or did:jwt (this an experimental method by David Chadwick)
> b) add in the context of the credential "https://w3id.org/security", or create a credential type that has the property publicKeyJwk, and add inside  "credentialSubject"  something like:
> 
> "publicKeyJwk": {
>      "crv": "Ed25519",
>      "x": "VCpo2LMLhn6iWku8MKvSLg2ZAoC-nlOyPVQaO3FxVeQ",
>      "kty": "OKP",
> }
> 
> I find the latter approach "cleaner" but I am not sure if it is correct. Any opinion?

What about the following

{
"@context": [
    "https://w3id.org/security/v1",
    { "ex": "http://example.org/vocab#" }
  ],
  "id": "#hs",
  "controller": "/people/henry#i",
  "publicKeyJwk": {
    "kty": "RSA",
    "n": "0vx7agoebGcQSuuPiLJXZptN9nndrQmbXEps2aiAFbWhM78LhWx4cbbfAAtVT86zwu1RK7aPFFxuhDR1L6tSoc_BJECPebWKRXjBZCiFV4n3oknjhMstn64tZ_2W-5JsGY4Hc5n9yBXArwl93lqt7_RN5w6Cf0h4QyQ5v-65YGjQR0_FDW2QvzqY368QQMicAtaSqzs8KJZgnYb9c7d0zgdAZHzu6qMQvRL5hajrn1n91CbOpbISD08qNLyrdkt-bFTWhAI4vMQFh6WeZu0fM4lFd2NcRwr3XPksINHaQ-G_xBniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw",
    "e":"AQAB",
    "alg":"PS512",
    "kid":"2011-04-29"
  }
}

which is equivalent to this Turtle

@prefix security <https://w3id.org/security#> .

</keys#hs>
     security:controller </people/henry#i> ;
     security:publicKeyJwk """{
                "alg":"PS512",
                "e":"AQAB",
                "kid":"2011-04-29",
                "kty":"RSA",
                "n":"0vx7agoebGcQSuuPiLJXZptN9nndrQmbXEps2aiAFbWhM78L..."
      }"""^^rdfs:JSON .



> 
> Best,
> Nikos
> 
> --
> Nikos Fotiou - http://pages.cs.aueb.gr/~fotiou
> Researcher - Mobile Multimedia Laboratory
> Athens University of Economics and Business
> https://mm.aueb.gr
>