{
  "tool_id": "art-583-beacon-seeded-fair-sampling-deriver",
  "tool_version": "1.0.0",
  "display_name": "Beacon-Seeded Fair-Sampling Deriver",
  "mcp_name": "derive_beacon_fair_sample",
  "mandate_type": "compliance_control",
  "wave": 82,
  "gpu": false,
  "url": "https://ainumbers.co/chaingraph/art-583-beacon-seeded-fair-sampling-deriver.html",
  "description": "Derives a deterministic, offline-replayable audit sample by HMAC-DRBG (SHA-256) seeded from a caller-pasted public randomness beacon pulse (drand quicknet or NISTIR-8213) combined with an item-manifest hash committed before the pulse round. Emits the selected item indices plus a full per-draw derivation transcript (seed, per-draw HMAC output, candidate index, accept/reject) so an examiner re-derives the identical sample offline from the transcript alone. Verdict DERIVED, or INDETERMINATE when inputs are missing or malformed. The beacon pulse, its round and its randomness are caller-declared inputs: the kernel performs SHA-256/HMAC math only, never fetches a pulse and never verifies the pulse's BLS signature, so a sample is only as trustworthy as the pulse the caller supplied. Committing the item-manifest hash before the pulse round is what makes the selection cherry-pick-proof, and the page teaches that ordering. Extends the assurance and workpaper family; cross-links the shipped art-471 disposition-sampling-frame rather than duplicating it.",
  "input_schema_ref": "chaingraph/art-583-beacon-seeded-fair-sampling-deriver.html#manifest",
  "consumes": [],
  "feeds": [],
  "status": "live",
  "conformance_fixtures": true,
  "compute_capability": "server",
  "compute_images": [
    {
      "system": "sha256-source",
      "image_id": "sha256:00bf25e2ac76c12d2bc9de448a1c9d767c67581310b599637d193d2f949b708a",
      "valid_from": "2026-07-10"
    },
    {
      "system": "risc0",
      "image_id": "sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6",
      "valid_from": "2026-08-07"
    }
  ],
  "compute_proof_ready": "ready",
  "deferred_reason": "New shard; awaiting the async GPU proving queue (S18 steady-state) — EDGE-PROVE-1.",
  "export_capability": [
    "json"
  ],
  "compute_proof": {
    "type": "ZkVmReceipt",
    "system": "risc0",
    "receiptFormat": "groth16-bn254",
    "imageId": "sha256:a1a0bc89b5b1febaeda3519f6dbade0fa5ac16beeb143c4e1b01689573567bc6",
    "seal": "EUdv+kISbTJSo3re25jJWV6C5XgGzRulrAO9F2C4acsWoZZvRgu11qQtPWVzp1LTS+34XTiiI0GrVqja63TdORb+kZuf9mlIbyXql3GEr7G9qcnqSXH8mRQyQcWSlXlqBcWdFj7pjAZKE72FP/lTeduS/71k+uQWIMkG3Sj88rAF/hkH8Prybn5nwQ3R1k6XjJChzj6LNPmgo3dA856GshcF4PDJn1BP27NVR57u708sEw2fMY/VnOFKL5fxfiHUHcdEWiBpYBTEn2trZNXkueVy1NZBGg7tWqVJ3T7siesZtqFNLjQEeIeh2fBz72EiAymDS5tSQfashU0OTRqRDQ==",
    "journal": {
      "chaingraph_version": "0.4.0",
      "kernel_digest": "sha256:00bf25e2ac76c12d2bc9de448a1c9d767c67581310b599637d193d2f949b708a",
      "output": {
        "algorithm_id": "hmac-drbg-sha256-v1",
        "beacon_randomness": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b85",
        "beacon_round": "4321000",
        "beacon_source": "drand_quicknet",
        "derivation_transcript": [
          {
            "accepted": true,
            "candidate_index": 106,
            "draw": 0,
            "hmac_hex": "c7c850c0be1cd7c6e88ad2f7615c1e776ffe5a9ea7a7111c0985d60417620870"
          },
          {
            "accepted": true,
            "candidate_index": 184,
            "draw": 1,
            "hmac_hex": "97bfae942d8b73791460e5a672cb83d8070b090257627d11da048b79d0a1dee9"
          },
          {
            "accepted": true,
            "candidate_index": 205,
            "draw": 2,
            "hmac_hex": "69ea8ff37d136f798f7a29e5a063daf44a62f0147d5f4b7d8cb92d6d0e8017d0"
          },
          {
            "accepted": true,
            "candidate_index": 91,
            "draw": 3,
            "hmac_hex": "57a20d8b60b445742b5c6af56574fcf20757ca472359d700969df7c6a9b184eb"
          },
          {
            "accepted": true,
            "candidate_index": 113,
            "draw": 4,
            "hmac_hex": "2707aaa70f87e79b251ac3e33ef64ca293079dedfc32da4181db305e5f3a0f7a"
          },
          {
            "accepted": true,
            "candidate_index": 99,
            "draw": 5,
            "hmac_hex": "0e59d463d5cfd53b6bb40bcd851ab6e67341b5e408102036a3f2d36eba69eeea"
          },
          {
            "accepted": true,
            "candidate_index": 199,
            "draw": 6,
            "hmac_hex": "27d8cc1964a825ff40092ccef8fb0e5a023e365abe683e803482e4b8c378dc12"
          },
          {
            "accepted": true,
            "candidate_index": 77,
            "draw": 7,
            "hmac_hex": "955917331707246538eeda870812cb0eeadbacf016df6ef1cc6ef070a2531737"
          },
          {
            "accepted": true,
            "candidate_index": 32,
            "draw": 8,
            "hmac_hex": "93229b7e5948d0ba0cfbf7c33a4ade9411c802a70d9c2feaf7d7280f819ba2a5"
          },
          {
            "accepted": true,
            "candidate_index": 158,
            "draw": 9,
            "hmac_hex": "e00cc5a01fd3b8c5042b719190a6a4f7690a502ab8b85b4f7030303470e9f1ac"
          }
        ],
        "draws_used": 10,
        "item_count": 250,
        "item_manifest_hash": "sha256:9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08",
        "sample_size": 10,
        "seed_hex": "e15a8aa2f6d6d3318be77fe06250a10823c3caf82c7d76b94b22cd80e40ddd0a",
        "selected_indices": [
          106,
          184,
          205,
          91,
          113,
          99,
          199,
          77,
          32,
          158
        ],
        "verdict": "DERIVED"
      }
    }
  }
}