April 30, 2011
JSON Web Key (JWK) Specification

I’ve posted the JSON Web Key (JWK) specification for representing public keys as JSON objects based on the decisions made at the last IIW. The introduction to the spec reads:

A JSON Web Key (JWK) is a JSON data structure that represents a set of public keys as a JSON object. The JWK format is used to represent bare keys; representing certificate chains is an explicit non-goal of this specification. JSON Web Keys are referenced in JSON Web Signatures (JWSs) using the jku (JSON Key URL) header parameter.

An example from the spec is:

{"keyvalues":
  [
    {"algorithm":"ECDSA",
     "curve":"P-256",
     "x":"MKBCTNIcKUSDii11ySs3526iDZ8AiTo7Tu6KPAqv7D4",
     "y":"4Etl6SRW2YiLUrN5vfvVHuhp7x8PxltmWWlbbM4IFyM",
     "keyid":"1"},

    {"algorithm":"RSA",
     "modulus": "0vx7agoebGcQSuuPiLJXZptN9nndrQmbXEps2aiAFbWhM78LhWx4cbbfAAtVT86zwu1RK7aPFFxuhDR1L6tSoc_BJECPebWKRXjBZCiFV4n3oknjhMstn64tZ_2W-5JsGY4Hc5n9yBXArwl93lqt7_RN5w6Cf0h4QyQ5v-65YGjQR0_FDW2QvzqY368QQMicAtaSqzs8KJZgnYb9c7d0zgdAZHzu6qMQvRL5hajrn1n91CbOpbISD08qNLyrdkt-bFTWhAI4vMQFh6WeZu0fM4lFd2NcRwr3XPksINHaQ-G_xBniIqbw0Ls1jF44-csFCur-kEgU8awapJzKnqDKgw",
     "exponent":"AQAB",
     "keyid":"2011-04-29"}
  ]
}

The specification is available at these locations:

I also updated the description of the JSON Web Signature (JWS) header parameter “jku” (JSON Key URL) to reference the JWK spec in draft -02.