We don’t know how [Kristoffer Marshall] found himself with free time at work, but he used it to beef up his computer security. Above is the finished project. There is literally nothing to see here. He’s rigged up a hidden RFID reader which locks and unlocks his workstation.

The security of the system depends on xscreensaver, which has a password protected lock feature already built into it. When the tag is removed from the reader’s field it fires up the screensaver using a Perl script.

But waking up from the screensaver is a bit more tricky. The package doesn’t allow you to wake it from the command line — most likely for security. He found the xdotool to be of great use here. It is a command line tool which simulates keyboard and mouse entry. His script detects when the xscreensaver password prompt is on the screen and uses the xdotool to fill in [Kristoffer’s] password. Since the script knows what has focus it won’t give away your password by accident.

See the complete setup in the clip after the break.