{
  "chain_slug": "polkadot",
  "name": "Polkadot",
  "scorecard_profile": "L1",
  "evaluated_at": "2026-04-18",
  "evaluator": "layerqu-v2-scoring-agent-4",
  "v1_reference": "chainscreen-v1-archive",
  "dimensions": {
    "1_cryptographic_exposure": {
      "weight": 0.15,
      "score": 52,
      "sub_scores": {
        "1a_primitive_inventory": {
          "score": 17,
          "primitives_named": [
            "Sr25519 (Schnorr over Ristretto25519)",
            "Ed25519 (GRANDPA finality)",
            "BLS12-381 (BEEFY bridge)",
            "BLAKE2b-256",
            "Sassafras VRF"
          ],
          "evidence": [
            "https://wiki.polkadot.network/docs/learn-cryptography"
          ],
          "note": "Comprehensive primitive inventory — multi-algorithm by design."
        },
        "1b_shor_grover_pq_tag": {
          "score": 17,
          "tags": {
            "Sr25519": "Shor-break",
            "Ed25519": "Shor-break",
            "BLS12-381": "Shor-break",
            "BLAKE2b-256": "Grover-weaken"
          },
          "evidence": [
            "https://wiki.polkadot.network/docs/learn-cryptography"
          ]
        },
        "1c_algorithm_family_diversity": {
          "score": 8,
          "families_represented": 2,
          "families": [
            "Lattice (Dilithium planned)",
            "Lattice NTRU (Falcon planned)"
          ],
          "note": "Roadmap names two PQC algorithms (Dilithium + Falcon) both lattice-based — lattice-monoculture concern but two schemes."
        },
        "1d_nist_security_category": {
          "score": 10,
          "mappings": {
            "Dilithium (planned)": "NIST cat 2-5 selectable",
            "Falcon (planned)": "NIST cat 1/5"
          },
          "note": "Specific NIST category selection not yet published in roadmap."
        },
        "1e_implementation_quality": {
          "score": 12,
          "formal_verification": "partial (Parity + Web3 Foundation audits)",
          "constant_time": "yes",
          "libraries": [
            "schnorrkel",
            "ed25519-dalek",
            "arkworks (BLS)"
          ],
          "evidence": [
            "https://github.com/paritytech/polkadot-sdk",
            "https://github.com/w3f/schnorrkel"
          ]
        }
      },
      "total_artifacts": 4
    },
    "2_hndl_exposure": {
      "weight": 0.1,
      "score": 28,
      "sub_scores": {
        "2a_active_key": {
          "score": 5,
          "note": "90-100% of accounts expose Sr25519 pubkey on first tx. Validator session keys permanently on-chain."
        },
        "2b_cold_key": {
          "score": 5,
          "note": "Same 100% exposure."
        },
        "2c_sig_long_term": {
          "score": 10,
          "note": "Active validator keys rotate via session keys — better than static EOA chains."
        },
        "2d_encryption_conf": {
          "score": 8,
          "note": "libp2p + TLS for validator comms. No PQC announced."
        }
      },
      "total_artifacts": 2
    },
    "3_metadata_privacy_exposure": {
      "weight": 0.13,
      "score": 40,
      "sub_scores": {
        "3a_graph_visibility": {
          "score": 8,
          "note": "Pseudonymous across relay chain + parachains."
        },
        "3b_rpc_concentration": {
          "score": 12,
          "note": "OnFinality, Dwellir, Ankr — multi-provider."
        },
        "3c_bridge_correlation": {
          "score": 12,
          "note": "XCM + Snowbridge — built-in bookkeeping but heterogeneous."
        },
        "3d_retroactive_deanon": {
          "score": 8,
          "note": "Some parachains (Phala) use TEE privacy. Most relay-chain data is public."
        }
      },
      "total_artifacts": 2
    },
    "4_migration_architecture": {
      "weight": 0.1,
      "score": 65,
      "sub_scores": {
        "4a_crypto_agility": {
          "score": 20,
          "note": "Substrate forkless runtime upgrades. Crypto module is pluggable. Can add new signature types via Wasm runtime upgrade without hard fork.",
          "evidence": [
            "https://wiki.polkadot.network/docs/learn-keys",
            "https://forum.polkadot.network/t/post-quantum-cryptography-roadmap-for-polkadot-and-jam/13232"
          ]
        },
        "4b_aa_key_rotation": {
          "score": 17,
          "note": "Proxy accounts + multisig. Session-key rotation native for validators.",
          "evidence": [
            "https://wiki.polkadot.network/docs/learn-proxies"
          ]
        },
        "4c_hard_fork_track_record": {
          "score": 15,
          "note": "Hundreds of forkless runtime upgrades. OpenGov referenda track record. Coordinated 2023 parachain vuln patch."
        },
        "4d_hybrid_deployment_readiness": {
          "score": 13,
          "note": "SS58 address format extensible. Runtime can accept hybrid signatures via envelope."
        }
      },
      "total_artifacts": 5
    },
    "5_deployment_execution": {
      "weight": 0.22,
      "score": 16,
      "sub_scores": {
        "5a_mainnet_pqc_pct": {
          "score": 0,
          "mainnet_pqc_pct": 0,
          "evidence": [],
          "note": "No PQC on mainnet."
        },
        "5b_pqc_code_in_consensus": {
          "score": 1,
          "loc_or_bytes": 0,
          "note": "QSB project on Substrate is external (Quantum Blockchains Inc), not Polkadot runtime."
        },
        "5c_validator_pqc_keys": {
          "score": 0,
          "pct": 0
        },
        "5d_published_milestones": {
          "score": 10,
          "count": 2,
          "milestones": [
            "W3F PQC Roadmap (June 2025) — Dilithium for consensus, Falcon for accounts",
            "JAM integration post-2026"
          ],
          "evidence": [
            "https://forum.polkadot.network/t/post-quantum-cryptography-roadmap-for-polkadot-and-jam/13232"
          ]
        },
        "5e_pqc_washing_delta": {
          "score": 5,
          "ratio": 1.5,
          "note": "Roadmap announced; no shipped code."
        }
      },
      "total_artifacts": 2
    },
    "6_supply_chain_vendor_readiness": {
      "weight": 0.22,
      "score": 10,
      "sub_scores": {
        "6a_wallet": {
          "score": 3,
          "top3": [
            "Polkadot.js",
            "Talisman",
            "SubWallet"
          ],
          "pqc_roadmap_count": 0
        },
        "6b_bridge": {
          "score": 3,
          "top3": [
            "XCM",
            "Snowbridge",
            "Multichain"
          ],
          "pqc_roadmap_count": 0
        },
        "6c_custodian": {
          "score": 2,
          "top3": [
            "Coinbase Custody",
            "BitGo",
            "Anchorage"
          ],
          "pqc_roadmap_count": 0
        },
        "6d_rpc_hsm": {
          "score": 2,
          "top3": [
            "OnFinality",
            "Dwellir",
            "Ankr"
          ],
          "pqc_roadmap_count": 0
        }
      },
      "total_artifacts": 2
    },
    "7_governance_coordination": {
      "weight": 0.08,
      "score": 78,
      "sub_scores": {
        "7a_validator_stake_distribution": {
          "score": 23,
          "note": "Nakamoto coefficient 149 — industry-leading.",
          "evidence": [
            "https://lew.am/polkadot-a-blockchain-platform-for-interoperability-has-a-nakamoto-coefficient-of-about-149-as-of-early-2025/"
          ]
        },
        "7b_upgrade_cadence_under_pressure": {
          "score": 22,
          "note": "Forkless runtime upgrades. Pi Day Reset 2026 (53.6% emission cut)."
        },
        "7c_named_coordination_lead": {
          "score": 20,
          "note": "Web3 Foundation + Parity + JAM working group. Published PQC roadmap."
        },
        "7d_adversarial_coordination_precedent": {
          "score": 13,
          "note": "2023 parachain vuln: $200M saved via rapid coordinated patch."
        }
      },
      "total_artifacts": 3
    }
  },
  "gates": {
    "hybrid_deployment": "PASS",
    "evidence_reconstruction": "PASS",
    "primitive_naming": "PASS"
  },
  "caps_applied": [
    "Mosca (5a<20% → QRI max 60)",
    "Aaronson (Dim 4=65 vs Dim 5=16, delta>25 → QRI max 70)"
  ],
  "qri": {
    "raw": 31,
    "after_caps": 31,
    "ci_plus_minus": 10,
    "band": 4,
    "band_name": "Architected"
  },
  "migration_stage": 2,
  "mosca_inequality": {
    "X_signature_shelf_life_years": "10-15 (validator session keys rotate)",
    "Y_migration_time_years_range": "5-10",
    "Z_10pct_year": 2036,
    "Z_50pct_year": 2041,
    "danger_zone_at_50pct": false
  },
  "four_scenario_grid": {
    "quantum_never": {
      "value_preserved_pct": 100,
      "privacy_preserved_pct": 100
    },
    "arrives_suddenly_pre_migration": {
      "value_preserved_pct": 10,
      "privacy_preserved_pct": 15
    },
    "arrives_slowly_post_migration": {
      "value_preserved_pct": 92,
      "privacy_preserved_pct": 80
    },
    "arrives_slowly_mid_migration": {
      "value_preserved_pct": 55,
      "privacy_preserved_pct": 50
    }
  },
  "burn_vs_rescue_policy": "undeclared",
  "pqc_washing_ratio": 1.5,
  "vendor_tile_summary": {
    "wallet": {
      "top3": [
        "Polkadot.js",
        "Talisman",
        "SubWallet"
      ],
      "pqc_roadmap_count": 0
    },
    "bridge": {
      "top3": [
        "XCM",
        "Snowbridge",
        "Multichain"
      ],
      "pqc_roadmap_count": 0
    },
    "custodian": {
      "top3": [
        "Coinbase Custody",
        "BitGo",
        "Anchorage"
      ],
      "pqc_roadmap_count": 0
    },
    "rpc_hsm": {
      "top3": [
        "OnFinality",
        "Dwellir",
        "Ankr"
      ],
      "pqc_roadmap_count": 0
    }
  },
  "narrative_summary": "Polkadot is Band 4 (Architected) — the only chain in batch with a published PQC roadmap (June 2025 W3F paper naming Dilithium + Falcon). Forkless runtime upgrades give unmatched crypto-agility: Substrate can ship hybrid PQC via runtime upgrade without hard fork. Industry-leading Nakamoto coefficient 149 supports Gate 1 pass. Capped by Aaronson (architecture Dim 4 far exceeds execution Dim 5). No mainnet PQC shipped yet; lattice-monoculture risk from Dilithium+Falcon both being lattice-based.",
  "evaluator_notes": "Top of batch. Strongest combination of architectural agility + governance + named roadmap. Main gap is execution (Dim 5 = 16) and vendor ecosystem (Dim 6 = 10). If W3F ships Dilithium runtime module in next 2y, can climb to Band 6-7.",
  "narrative_voiced": "Polkadot is the only chain in the batch with a named PQC roadmap. Dilithium and Falcon, both lattice-based, announced by W3F in June 2025. Forkless runtime upgrades mean they can ship without a hard fork. The architecture is further along than anyone's execution, including their own. Band 4 because paper is not production."
}