A JSON Web Key (JWK) is a standard JSON data structure representing a cryptographic key and the parameters needed to load and use it. Fields such as kty identify the key family, while algorithm-specific values describe the key itself. section 7.5.2 section 8.4.2
Common JWK fields include:
- kty identifies the cryptographic key type, such as RSA or EC. section 8.4.2
- use indicates whether a public key encrypts data (enc) or validates signatures (sig). section 8.4.2
- kid identifies a particular key, while RSA keys use values such as n and e to represent the modulus and public exponent. section 8.4.2
Validating an OIDC access token
An OIDC provider publishes public JWKs through its JWKS endpoint. A validator reads the JWT header’s kid, selects the matching JWK, loads its public key, and verifies the token with a fixed algorithm such as RS256, expected audience, and issuer. section 8.4.2 section 8.7
