How to Password Protect Files on a Mac

Creating the Disk Image

1. 
   Open Disk Utility. Click Spotlight

   

   , type in disk utility, and double-click the Disk Utility result.

   1. You can also find Disk Utility in the Utilities section of the Finder's Go menu item.
2. 
   Click File. It's in the upper-left side of the screen. A drop-down menu will appear.
3. 
   Select New Image. This is near the top of the File drop-down menu. Selecting it will prompt a pop-out menu to appear.
4. 
   Click Image from Folder…. It's in the pop-out menu. Doing so will open a new window.
5. 
   Select the folder that you created. Go to the Desktop folder by clicking the drop-down box at the top of the window and clicking Desktop in the drop-down menu, then click your created folder.
6. 
   Click Open. It's in the bottom-right corner of the window.
7. 
   Enter a title for your folder. Type whatever you want to name your protected folder into the "Save As" text box.

   1. You cannot use the same title as the folder that you created or any other folder on your desktop.
   2. You can also select a save location by clicking the "Where" drop-down box and then selecting a folder in the drop-down menu.
8. 
   Click the "Encryption" drop-down box. It's near the bottom of the window. Clicking it prompts a drop-down menu.
9. 
   Click 128-bit AES encryption (recommended). You'll find this option in the drop-down box. Doing so opens the password window.^[1]
10. 
    Create a password. Type your preferred password into both the "Password" text box and the "Verify" text box, then click Choose in the bottom-right corner of the password window.
11. 
    Click Save. It's a blue button at the bottom of the window. Doing so will save your settings and create your password-protected folder.
12. 
    Use the password-protected folder. To open the folder, double-click it, then enter the password that you set for it when prompted. The folder will open, and a drive-shaped icon will appear on your desktop.

    1. You may have to restart your Mac before the folder will ask for your password.
    2. You can close and re-protect the folder by moving the drive-shaped icon into the Trash and then restarting your Mac.