{
      "tool_id": "art-124-content-credential-signature-verifier",
      "tool_version": "1.0.0",
      "display_name": "Content Credential Signature Verifier",
      "mcp_name": "verify_content_credential_signature",
      "mandate_type": "compliance_mandate",
      "wave": 23,
      "gpu": false,
      "url": "https://ainumbers.co/chaingraph/art-124-content-credential-signature-verifier.html",
      "description": "Verify the COSE_Sign1 claim signature against a caller-supplied signer public key using crypto.subtle.verify (Ed25519/ES256/ES384/PS256). Trust-anchor membership, cert validity window, and revocation status are caller-supplied policy inputs: zero network, no OCSP. Emits ACCEPT or REFUSE verdict.",
      "input_schema_ref": "chaingraph/art-124-content-credential-signature-verifier.html#manifest",
      "consumes": [
        "art-123-c2pa-manifest-validator"
      ],
      "feeds": [
        "art-125-provenance-ingredient-tree-resolver"
      ],
      "status": "live",
      "conformance_fixtures": true,
      "compute_capability": "server",
      "compute_images": [{"system":"sha256-source","image_id":"sha256:e9897ef4cb8f7cf9529ef898e949895809edb037f346eb0a0557216bb3875fd1","valid_from":"2026-07-10"},{"system":"risc0","image_id":"sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6","valid_from":"2026-06-28"}],
      "compute_proof": {
        "type": "ZkVmReceipt",
        "system": "risc0",
        "receiptFormat": "groth16-bn254",
        "imageId": "sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6",
        "seal": "DTiWrpKO5m6/QiLeFmB+uKgqChdA70nt2Yx6igTMggswGFCiDoxZVVjDuBtvs3tBtjIKCwfy09HmlvhphYUyAyPiuVf8mDPOLmGz2bX0dRLCCmn/noibNdCsQ/p++LkJAMOIyCdfheJHgtVVE0Q4KF1CYFa6H6g2zC8AOmMRR0spX3Au/W6cJjcZ4sRMb+DWpE0RKBTUHuYVK37b2A60BxpmyIl0ucVGM66oE2WFktpwjS9iNLNVgMSlkXO+t5IVEMMy5H2HkPo/g6T4LrMBVWYHQyx5iFwjJY1GmX3W9Hsggp3xGuZFDk4TXdzpnqVcy6nir6FNmcy2FGlMrfPAuw==",
        "journal": {
          "chaingraph_version": "0.4.0",
          "kernel_digest": "sha256:141e6f335fbfd58ba9b12166c03841fc193eee0fcde37e4ac18b332055a9fed7",
          "output": {}
        }
      },
      "export_capability": [
        "xlsx",
        "csv",
        "pdf",
        "xbrl:ocg-ext"
      ]
    }