OS X Mavericks: Require a password after waking your Mac
To keep the information on your Mac secure when you are away from it, set it to require authentication when it wakes from sleep. When you return to your Mac, type your login name and password to continue working.
- Select “Require password for sleep and screen saver.”
- Choose the amount of time before a password is required from the pop-up menu.
To lock your screen quickly when fast user switching is enabled, choose Login Window from the menu with your user name. Your apps and documents remain open and undisturbed, but your Mac is locked.
Locking the screen doesn’t prevent other users from turning off the computer, restarting it, and logging in. If you think this could happen, and you use apps that don’t automatically save your changes, be sure to save your work before you leave your computer.
You can use your administrator name and password to unlock the screen for yourself or a standard user, but not for another administrator.