On Linux, one could use dm-crypt in plain mode with keys on number of flash drives. Good thing about keys, they look like unformatted disks, so you can send fla

On Linux, one could use dm-crypt in plain mode with keys on number of flash drives. Good thing about keys, they look like unformatted disks, so you can send flash drives via mail in advanced. Whenever you open a laptop like this without a key inserted, it look like it has no bootloader, no OS. There is no metadata, no nothing. Get ready to have your devices seized though =).