Setting up security features on a Mac

Learn how to password protect your mac and create encrypted disk images to protect data.

Password Protect Your Mac at Login

Disable your Mac's auto-login. This will prevent your Mac from going straight to the Finder when you turn it on. You'll be required to type a password to access anything.

Here's how to do it:

  • From the Apple menu, select System Preferences.
  • Select Security.
  • Check the Disable automatic login checkbox.
  • Click the back button to return to the main System Preferences window.
  • Select Accounts.
  • Select Login Options. Make sure "Automatically Login as" is unchecked. Under Display login window as, select either List of users or Name and password.  The List of users option will provide a list of users when you first start up your Mac. To log in, you click on your user name and type your password. Use the Name and password option for an added layer of security. This will require you to type in both your user name and password. Unauthorized users will have to guess two things instead of just one!  Use a list of users (left), or type in both your user name and password (right).
  • Close the System Preferences. The next your turn on your Mac, you'll be required to enter your user name and password!


Lock Your Mac While You're Away

Everyone walks away from their computer. The next time you take a break, lock your Mac to prevent unauthorized access. Here's how:

  • From the Apple menu, select System Preferences.
  • Select Security.
  • Check the checkbox next to Require password to wake this computer from sleep or screen saver.
  • Click the back button to return to the main System Preferences window. Select Desktop & Screen Saver.
  • Click Hot Corners. Choose the corner you want to activate the screen saver, and select Start Screen Saver from that corner's menu.
  • Click OK. Close the Systems Preferences. You can now activate your screen saver - and password protect your Mac - by moving the pointer into the corner you set as the hot corner. Anyone who tries to deactivate the screen saver will need to enter your password!


Create an encrypted disk image to store your confidential data

1. Launch Disk Utility (/Applications/Utilities).

2. Choose File > New > Blank Disk Image and enter a name for your disk image in the Save As field. This name is used for the disk image (.dmg) file. Note the location specified in the Where pop-up menu. If you want to save the image file in a different location, change it.

3. Select a size for the image file from the Size pop-up menu. Choose a size appropriate for the disk’s needs. You can always create another one later if you need more space.

4. Choose 128-bit AES encryption from the Encryption drop-down.

5. Choose read/write disk image from the Image Format drop-down.

6. Click Create.

(When you select a password for your disk image, Disk Utility tells you what it thinks of the password’s strength—that is, its crackability.)

7. Enter and verify a good password in the dialog window that appears. This password will be saved in your Keychain by default, or you can deselect “Remember password (add to Keychain)” if you don’t want that.  If others have access to your computer, it is recommended that you uncheck "Remember password".  Otherwise anybody who opens the disk image will be able to access the data you store in it.  If you uncheck remember password and you are not able to remember the password, the information contained in that file can never be recovered.

8. Click OK.

9. You are ready to use your disk image to store your confidential data.  Simple double click on it to mount it on your desktop and drag files into it.  Remember to delete any other copies of these files from your hard drive.

10. After each time you use your disk image, ensure that you unmount (eject) it.

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