Есть ли способ зашифровать жесткий диск таким образом, чтобы невозможно было доказать, что он зашифрован?

xwrits, доступный в стандартном репозитории, — это еще один.

Description: reminds you to take a break from typing
 xwrits helps you prevent repetitive stress injury.
.
 xwrits is a small reminder program designed to let you know it is time
 to take a break from typing to rest your wrists and prevent any damage
 to your wrists (or at least make them feel better if you've already
 damaged them). Normally works on the honor system, but if you find
 yourself unable to stop typing during your break, it can also lock your
 keyboard.