Cybersecurity
19 Sep 2026
7 min read
JWS Key Selection Is a Trust Decision, Not a Header Instruction
JWS Key Selection Is a Trust Decision, Not a Header Instruction A signed token can carry enough metadata to point a verifier toward a key. A JWS protected header can name an algorithm with alg, identify a key with kid, or, in profiles that permit them, carry or reference key material through parameters such as jwk, jku, x5c, or x5u. Those fields are useful for routing verification work, especially during key rotation.