Transshipment used to settle title on a bill of lading plus a commercial invoice; banks audited a paper chain. Bonded zones now require a one-to-one match between the receipt and the physical lot, and every issuance, endorsement and cancellation must leave a trail. Which ESPO batch entered which tank, when it moved, and who finally lifted it has to be pullable from one panel.

The value of SHA-256 here is not a chain gimmick — it fixes each receipt-state change into a 256-bit fingerprint. The receipt hashes once at issuance and again at every endorsement; any party can recompute from the raw fields and compare, so tampering surfaces immediately. That gives customs, the negotiating bank and the buyer one shared, non-repudiable record.

For operators the hit lands on settlement timing. The RMB cost of dollar cargoes moves with USD/CNY at 6.7114, and the old phone-locked FX window has shrunk. With receipts notarized on-chain, a bank can release 80% of the negotiation at the "endorsed, not yet lifted" state and hold 20% until lifting confirmation — cutting the funding cycle from 7 days to under 3.

Rollout advice: standardize receipt fields first (grade, quantity, tank, batch, counterparty DID), then attach the notarization service. SNSUC's digital-receipt module generates the SHA-256 fingerprint in the browser, never on a server — traceable without exposing the commercial position to a third party.