Turn screen off with a shortcut and turn it on ONLY if you press the same screenshot [closed]

I have problems with my friends using my laptop, and I am wondering if there is a way to turn the screen off with a shortcut such as CTRL + F12, and turn it on ONLY if CTRL + F12 is clicked, and not when the user starts typing randomly or moving the mouse. It's fine if it's an application.

EDIT: Like this program http://www.addictivetips.com/windows-tips/sleeper-lets-you-turn-off-your-computer-screen-with-a-hotkey/ but so it doesn't wake up on mouse moving/keyboard.

You really should use password authentication instead. It's the obvious answer, but you really, really, really should.