The weakest link in a paper warehouse receipt is the question of who signed it and whether the cargo still sits in the warehouse. We hash the receipt's key fields: commodity, quantity, warehouse, title holder, timestamp, locally in the browser with Web Crypto's SHA-256, then anchor the result on-chain or to storage. The merchant never sends commercial detail to a central server; no data leaves the device before the fingerprint exists.

SHA-256 is deterministic: the same input always yields the same 64-character hexadecimal string, and anyone can recompute and verify it. On transfer, the new title holder rehashes the raw fields and compares the digest against the root stored on-chain. A match proves the document was not altered. This swaps trust in a third party for trust in the math.

On the ESG side we fold each lot's carbon-footprint fields: transport mode, distance, energy use, into the same digest. A buyer verifying the receipt also sees the cargo's carbon intensity, and that field feeds straight into accounting for markets with a carbon border adjustment. The receipt moves from a title instrument to a title instrument carrying carbon data, a real reduction in compliance lift for regulated trade.