Handy screen locking tips for Mac

Mac does not enable screen-locking that requires an unlocking password by default, but you can enable this capability. Vincent Danen offers a few easy methods to set up screen-locking for better security.

With Fedora, and most other Linux distributions, hitting CTRL-ALT-L by default will engage the screensaver and lock the screen. With Windows, hitting CTRL-ALT-DEL engages the screensaver and locks the screen. On the Mac, however, there is a rather strange keyboard combination that will blank the screen (CTRL-SHIFT-EJECT), but by default does not lock the screen. For a Mac to be considered as secure as Linux or Windows in the work place (or by anyone that values their privacy), making it so that a quick keyboard combination locks the screen is an absolute must.

Unfortunately, while OS X has this capability, it is not enabled by default. To enable requiring a password when the system has started the screensaver, start System Preferences and go to the Security section. Under General, enable the Require Password After Sleep Or Screen Saver Begins. You can specify a timeout as well, so that OS X will only require a password after the screensaver has been active for a minute, or five minutes. This would largely depend on your needs and whether or not you have a short idle timeout (which is defined in the Energy Saver section of System Preferences).

Once this preference is enabled, you can use the CTRL-SHIFT-EJECT shortcut to start the screensaver. If you use Windows or Linux, this shortcut is extremely different and possibly difficult to remember if you are not used to it, but luckily OS X makes it easy enough to make it something more memorable.

If you're a heavy mouser, then enabling one of the screen corners to be a "hot corner" to enable the screensaver might work best. To do this, in System Preferences, go into Desktop & Screen Saver and select the Screen Saver tab. At the bottom of the pane there is a Hot Corners... button that, when clicked, allows you to define which corner of the screen you can mouse to in order to engage the screensaver. There are a few options: enable screensaver, disable screensaver, and put display to sleep (amongst others). To use the mouse to quickly lock the screen, choose Start Screen Saver and select which corner you want to use; I'd suggest either the bottom left or right corners to avoid accidentally triggering it when using the menubar.

If mousing to part of the screen isn't your thing, you can use the keyboard to lock the screen, but it takes Automator (or a third-party application, but Automator is the better bet if you're using OS X 10.6). Launch Automator and create a new service.

Tell the new service that it receives "no input" (rather than the default of "text"). The default is also for "any application", make sure to keep this set. Next, drag the Start Screen Saver action from the Utilities action group to the workflow. Finally, save the service and give it a name, such as Start Screensaver. Go back to Keyboard Shortcuts in the Keyboard section of System Preferences and look in the Services group. Scroll down to the General section and you will see the newly created Start Screensaver service is enabled. Click in the whitespace to the far right of this entry and a new entry box will appear. Type the keyboard shortcut, such as CTRL-OPT-L.

Exit System Preferences.

You will now be able to hit CTRL-OPT-L and activate the screen saver in order to lock the screen. If you wish to return to the login window instead (you are still logged in, but the computer is locked) rather than activate the screensaver, change the Automator service to Run Shell Script instead of Start Screen Saver and have it run the following command:

/System/Library/CoreServices/Menu\ Extras/user.menu/Contents/Resources/CGSession -suspend

Depending on your needs, you may prefer hot corners, or you may prefer keyboard shortcuts. For myself, hot corners always seem to get triggered by accident, so a keyboard shortcut is ideal.


Vincent Danen works on the Red Hat Security Response Team and lives in Canada. He has been writing about and developing on Linux for over 10 years and is a veteran Mac user.


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"the CTRL-SHIFT-EJECT shortcut to start the screensaver. If you use Windows or Linux, this shortcut is extremely different and possibly difficult to remember if you are not used to it" Sorry, whut? Anyone who regularly uses a mac should have no problem remembering this. If you can't remember a simple 3-key combo on any platform then you probably shouldn't be using a computer in the first place. And to ask those who can't remember a simple combo to setup an Automator action?? Yeah, right...


I agree 100% to locking a workstation when the user has left. I lock mine all the time, and hey, I live alone and I even lock my workstation every time I get up to go to the kitchen [force of habit I'm sure!]. On Windows, I use Windows Key+L, which is shorter than CTRL+ALT+DEL, since that only brings up task manager if you're running Windows XP Home or Professional [running on a workgroup instead of domain] unless you have the Welcome Screen disabled [which I do]. This will bring up the Windows Security dialog box pressing CTRL+ALT+DEL instead of the Task Manager if you have the Welcome Screen off, and then it's just a matter of hitting ENTER once, as the "Lock Computer" button is the first option highlighted in the Windows Security box. On my Mac, I thought about the idea of hot corners, and I could see the screensaver password protection working for some people, but for me I wanted something more like the Computer Locked dialog box that comes up in Windows XP, or sending you to the lock welcome screen on Vista, 7, or Server 2008. My solution was to install a free product for the mac called SizzlingKeys which ads a new icon in System Preferences under "Other". Then I open SizzlingKeys, and choose the option in the top right to "Launch automatically at login" so that the program is actively waiting for a command. I then go to the Extras tab in SizzlingKeys, and check the box for "Lock Computer". I have my keyboard shortcut to CTRL+L. Instead of sending me to the screensaver, it gives me the exact same kind of lock screen as Windows does, with a password prompt box and a nice background [this is the same box you would get when you have Fast User Switching enabled and switch users, although I only have one user]. When I leave my office, I simply Windows Key+L my PC, and CTRL+L my Mac, and I'm secure. Takes about 1.5 seconds total to lock the systems, and both systems display a nice locked login box. Give 'er a shot!