Prove that a subcontractor chain of any depth is trusted and authorised. Without exposing the carriers in it. Full chain unsealed only on incident audit.
Trigger
A authorises the next link inside Trusted Carrier; that link authorises the next, to any depth. Each authorisation is sealed pairwise.
We verify at source
At the gate and on the shipper's side, the answer is one signed yes or no: this driver belongs to a carrier inside A's authorised chain. The intermediaries stay sealed.
Outcome
Driver-level QR codes resolve back to their employer and the active assignment, so the dock confirms identity without seeing the chain above.