{"alg":"Ed25519","key_id":"a5c0675252a36d90","public_key_b64":"ycdVNjSZRcwp1KGoehOaBSBCcrZgfhHT0jTlwzz97+4=","signs":"sha256 of the canonical JSON in `attestation.payload`","verify":"ed25519.verify(sig_b64, sha256(canonical_json(payload)))"}