certificateSha1Thumbprint
The "x5t" (X.509 certificate SHA-1 thumbprint) parameter is a base64url-encoded SHA-1 thumbprint (a.k.a. digest) of the DER encoding of an X.509 certificate (RFC5280). Note that certificate thumbprints are also sometimes known as certificate fingerprints. The key in the certificate MUST match the public key represented by other members of the JWK. Use of this member is OPTIONAL.