PoV Core: Attestors, One-Claim & Claim IDs

Summary: Proof of Verification (PoV) is an application-layer standard on Ethereum/Base. It gates mints/settlements by requiring a governed attestor quorum on the same evidence and enforcing route-agnostic One-Claim exclusivity. It is not base-layer consensus.

What this page covers

• Roles & quorum policy (attestors and the default QuorumSpec)

• Canonical evidence → evidenceHash (why and how to hash)

• EAS schemas you reference in proofs: MeterReadingBatch.v1, Verification.v1

• Route-agnostic claimId and the One-Claim exclusivity rule

• The invariants PoV requires on every mint/settle

Roles & quorum policy

Base roles (v0.1):

• 1 = METER_OP (or Source Operator)

• 2 = AUDITOR (independent verifier — mandatory)

• 3 = OEM (device maker / device attestation)

• 4 = GRID (TSO/DSO/market operator)

• 5 = CUSTODIAN (asset/collateral)

• 6 = INSPECTOR (lab/QA/assay)

• 7 = PROGRAM (grant/issuer/authority)

Default QuorumSpec (v0.1): minTotal = 2, auditorRequired = true, minDistinctRoles = 2

Governance MAY tighten by product line (for example, require AUDITOR + GRID for compliance REC).

Canonical evidence → evidenceHash

Why canonicalize: the same reality must hash to the same bytes. Pretty-print tricks or field re-ordering must not change the digest you verify on-chain.

Canonical JSON rules (normative):

• Sorted keys (ASCII ascending)

• UTF-8 encoded

• Minified (, : separators only)

• Numeric fields are integers unless explicitly declared decimal strings

Minimal energy example:

{"batch_id":"0x<32-byte>","device_id":"0x<32-byte>","start_ts":1698796800,"end_ts":1698883200,"quantity_wh":10000,"nonce":"0x<32-byte>"}

Hash: evidenceHash = SHA-256(utf8(canonical_json))

EAS schemas (attestations you reference)

MeterReadingBatch.v1

Fields (revocable):

bytes32 batchId,
bytes32 deviceId,
uint64  startTs,
uint64  endTs,
uint128 quantityWh,
bytes32 evidenceHash,
uint64  createdAt

Verification.v1 (PoV unit attestation)

Fields (revocable):

bytes32 batchId,
bytes32 refMeterUID,   // links to MeterReadingBatch
uint8   role,          // 1..7 (see Roles)
uint8   outcome,       // 1=PASS, 2=FAIL
uint64  verifiedAt,
uint64  validUntil,    // 0 => no TTL
bytes32 evidenceHash,  // must equal MeterReadingBatch.evidenceHash
bytes32 methodHash     // e.g., keccak256("IEC_62053-21+ProcessA")

Rule: counted verifications MUST reference the same evidenceHash and batch/window as the meter attestation.

Route-agnostic claimId

Purpose: prevent the same evidence from being consumed across routes/registries. If you need splits, create smaller batches and attest them independently

Definition:

• Solidity

bytes32 claimId = keccak256(
  abi.encodePacked(deviceId, startTs, endTs, quantityWh, evidenceHash)
);

• TypeScript

import { solidityPackedKeccak256 } from "ethers";
const claimId = solidityPackedKeccak256(
  ["bytes32","uint64","uint64","uint128","bytes32"],
  [deviceId, startTs, endTs, quantityWh, evidenceHash]
);

One-Claim exclusivity

Contract: One-Claim Ledger records the first (and only) successful consumer of a claimId.

API (conceptual):

• reserve(claimId) → succeeds only if unclaimed; locks to msg.sender

• finalize(claimId) → only reserver can finalize; emits Finalized

• release(claimId) → only reserver can release before finalization

Atomicity: reserve → checks → finalize MUST occur inside the Gate in a single transaction; any revert rolls back the reservation

PoV invariants (MUST hold)

1. Equality of evidence — all counted verifications reference the same evidenceHash and batch/window

2. Quorum — at least minTotal, with ≥ 1 AUDITOR, and ≥ minDistinctRoles

3. Exclusivity — a claimId can be finalized exactly once network-wide

4. Revocability — if a counted verification is revoked/expired and quorum drops, dependent assets MUST be flagged/frozen/burned per policy until rectified

5. Fail-safe — uncertainty means no mint/settle/access (revert

Conformance checklist (integrators)

• Produce canonical JSON and compute evidenceHash

• Publish MeterReadingBatch.v1 for the batch

• Obtain ≥ minTotal Verification.v1 attestations (same evidenceHash; includes AUDITOR)

• Compute route-agnostic claimId

• Call the PoV Gate in the same transaction that mints/settles/accesses; Gate will reserve → validate → finalize in One-Claim

• Store attestation UIDs and emitted events for audit (subgraph/indexer)

• Subscribe to the PoV Feed and implement flag/rectify handlers in your asset contracts