The real risk in re-export is rarely price — it is unclear title. A cargo of ESPO may load in the Middle East, transship at Singapore, and discharge in Shandong, changing hands three times along the way. The traditional route uses bill-of-lading endorsement plus telegraphic release, with each hand-off confirmed on paper or by email. Lose one voucher and ownership goes floating.

Moving title online is simpler than it sounds. At each title transfer, take four elements — who, which parcel, when, at what price — together with the previous record's hash, and compute a SHA-256 value to write in. The next transfer takes that value as its input, chaining the records. Anyone can verify in a browser without a central authority.

For SNSUC's seven re-export grades — ESPO, Dubai, Oman, Urals, Basrah Light, Bonny Light, Lula — this means ownership stays traceable through multiple resales. Before paying, a buyer checks the last on-chain hash and timestamp to confirm the cargo is still in the seller's name and not double-pledged, then releases funds. That step alone removes a large share of double-sale risk.

Note that on-chain title governs tamper-proof recording, not automatic legal effect. It complements the bill of lading and the sale contract; it does not replace them. In practice the on-chain timestamp must align with the actual document handover to avoid two clocks disagreeing. Our approach generates the hash in the browser and stores only the fingerprint on-chain, keeping the underlying contract off the ledger for both traceability and confidentiality.