Optional
ctyContent Type Header Parameter
Optional
jkuJWK Set URL Header Parameter
Optional
jwkJSON Web Key Header Parameter
Optional
kidKey ID Header Parameter
Optional
typType Header Parameter
Optional
x5cX.509 Certificate Chain Header Parameter
Optional
x5tX.509 Certificate SHA-1 Thumbprint Header Parameter
Optional
x5uX.509 URL Header Parameter
JSON Object Signing and Encryption (JOSE) Header Parameters
The Header Parameter names for use in both JWSs and JWEs are registered in the IANA "JSON Web Signature and Encryption Header Parameters" registry.
As indicated by the common registry, JWSs and JWEs share a common Header Parameter space; when a parameter is used by both specifications, its usage must be compatible between the specifications.
See
RFC 7515, Section 4.1