The weak point of a digital warehouse receipt is time. When two title transfers happen in the same minute, the on-chain block order may not reflect the real operational sequence, and in litigation 'I was on-chain first' alone is not a hard claim. SHA-256 fixes content immutability but not 'who was first.'

A trusted timestamp authority (TSA) is a state time-source issuing provable time evidence: you submit an SM3 digest and receive a signed timestamp token proving that this data existed at that instant. Paired with the domestic SM3 standard — China's own replacement for the SHA family — the moment a title was created and which hand claimed it first is pinned by a third-party clock.

For banks and operators the gain is faster dispute resolution. In a title conflict the TSA token is ready-made evidentiary origin, requiring no wait for on-chain finality and no reverse-engineering of block times. SNSUC's receipts move from 'hash notarization' to 'judicial-grade notarization with a trusted timestamp,' adding one more certainty to lending controls.

Mind the boundary: a TSA proves existence time, not content truth. Whether the cargo is still there and the quantity is right still rests on IoT level gauges and the receipt state machine. The timestamp anchors the title timeline, not the title itself.