Couriers
I'm probably going over old ground here (various British cock-ups) - but why, when you're moving such sensitive data, isn't it held in the safekeeping of the same human being(s) from the beginning of its journey to the end of it? No sorting offices, no handovers: the courier takes it from the sending office to the receiving office, and does not allow himself to be distracted from that task.
OK, maybe in USA these can be quite long journeys. Even so, I would still give it to one trusted guy (or pair of guys) to take from A to B, with strict instructions about never letting it out of their sights.


