NTFS Security Question

Any other PC would need to have the exact same user account info on it for things to work as you want.

So if you have a user account with the name "joe" and you want to use the drive on another computer, that computer would also need a user account named "joe", and you'd need to be logged in as "joe" to access it seamlessly. Even then there's really no guarantees. Security and usability are often on opposite ends of the spectrum, so to have more of one, you give up some of the other. You'll have to find some kind of happy balance that works for you between those two.

maintain security you must first have identical user accounts on every pc the hard drive will be connected to.

Then the hard drive MUST be mounted in a removable cassette (need not be plug and play if cold booting each time.

Then, whenever the pc is not in actual use (operator sitting right there in front of it) you must remove the drive and lock it in the safe.

You must also limit the users or groups that have the right to take permission of files and folders.

You should also take great care to not share the drive on the network.

This will work if you are prepared to always ensure that all of the above is followed religiously because if a user steps away from the computer without removing and securing the drive the security settings will not necessarily apply as anyone with physical access could bypass with another OS.