The double-counting problem
A solar farm generates 10,000 kWh. That energy can back exactly one tradable certificate. If it backs two, one as an ETT, another as a Carbon Credit, or just two ETTs minted by different parties, the entire ESG market's integrity collapses. Buyers stop trusting the receipts. The market stops functioning.
Real-world asset markets have lived with this problem for decades. Voluntary carbon markets were exposed in 2023 as having massive double-counting issues, credits being sold by both the project owner and the host country. The reason was simple: there was no enforced uniqueness layer. Spreadsheets, registries, and goodwill.
PoV solves this at the contract level. Every claim carries an evidenceHash. The protocol maintains a global registry of hashes that have been finalised. If a claim references a hash that's already finalised, gate 03 rejects it, no matter what operator submits it, no matter what route it targets.
How exclusivity is enforced
- 01
Canonical hash from canonical JSON
Evidence is serialised with strict canonicalisation (RFC 8785 inspired). Identical facts produce byte-identical strings, which produce byte-identical SHA-256 hashes. There is no ambiguity in what "the same evidence" means.
- 02
Global registry, not per-route
The protocol keeps a registry of all finalised hashes. It's global, meaning the same hash can't be used on Route A (ETT mint) and Route B (Carbon Credit NFT) and Route C (REC). Different asset class, same underlying physical event, same exclusion.
- 03
First valid finalisation wins
When multiple claims arrive against the same hash, the first one to pass all three gates wins. Subsequent attempts hit gate 03 and are rejected, but the rejection is itself recorded on-chain, so attempts at double-counting are publicly auditable.
Real-world consequences
Energy: real ETT scarcity
One MWh of verified solar mints exactly 100 ETT (1 ETT per 10 kWh). No way to mint a second batch off the same generation. ETT supply is mechanically tied to verified generation, not to issuance policy.
Trade: no milestone fraud
A Bill of Lading that funded an inspection-stage EDSD release cannot also fund a duplicate release on the same order, or on a different operator's order. Each evidence event funds exactly one milestone.
Carbon: no shadow accounting
A carbon project's monitoring report can mint Carbon Credit NFTs once. The host country cannot also issue REC-style credits against the same generation. The exclusion is enforced before mint, not negotiated after.
