What is JWT x.509 Certificate Chain (x5c)?

What is JWT x.509 Certificate Chain (x5c)? In the JSON Web Token (JWT) standard, the "x5c" (x.509 certificate chain) claim is an array of strings that contains the x.509 certificate chain that was used to verify the digital signature of the JWT. This is used to verify the authenticity and integrity of the JWT, and to prevent JWT token abuse. The "x5c" claim is an optional claim, but it is recommended that it be included in the JWT if it is available. The value of the "x5c" claim must be an array of strings that contains the x.509 certificate chain, in order from the root certificate authority to the signing certificate. The authorization server can then use the "x5c" claim to verify the validity of the JWT, and to determine which certificate chain was used to verify the digital signature of the JWT. This can be used to implement JWT signing certificate policies, and to prevent JWT token abuse.