I have used products from
subrosasoft
Maybe this is where you need to go...
In my opinion, if you can't trust the people in your control room, you have bigger problems than drive encryption can solve.
As for transporting the data, put it in a box with tamper-evident seals.
We routinely serialize our ref CDs, and we put ISRC codes on every mix. I love it when I bust someone for trying to sell a pre-release on ebay (it happens on every release- I once had to fire a much loved engineer for selling a pre-mastered copy of a big release). We're registered eBay "VeRO". Do you not trust the person unpacking the box of drives?
I think responsible drive handling and password protected backup tapes with secure storage should cover most any situation, short of government or DOD contracts. Add a mandatory NDA and employment contract for anyone within earshot of the control room, and you'd think you'd be ok... but I guess some people will steal anything, anytime, so I guess you do what you have to do... best of luck...