FileVault

Mac OS X has built-in software to encrypt your home folder.  No additional software is needed.

To prevent others from seeing or copying files in your home directory on OS X, you can use the built-in FileVault software to encrypt your home folder.  The files and folders in your encrypted home folder are only accessible by the username and password for your account.  Other users, including administrators, are unable to access your profile if it is encrypted with FileVault.

If you forget the password for an encrypted FileVault account, files and folders in that account will be unrecoverable.  Mac OS X includes File Vault recovery features - a recovery key and an option to store recovery information with Apple.

Information about converting your account

When you enable FileVault for your account, it will convert your home folder into a FileVault file which will appear as a single encrypted file to unauthorized users.  This conversion process will take a few hours, but runs in the background so you can continue working.  During the conversion process you will need as much free space as your home folder is taking up, as FileVault copies your home folder into a new encrypted file.  For example, if your home folder is taking up 40GB of space, you will need at least 40GB of free space available. 

To check your available disk space and size of your home folder, in the Finder menubar, select Go > Computer.  Click on your computer's hard drive (usually Macintosh HD).  In the menubar, click on File > Get Info.  A window will appear and one of the items will be Available.  That is how much free space is on the computer. Close that window, and back in the Finder window, click on the Users folder, then your home folder. In the menubar, click on File > Get Info.  A window will appear and OS X will calculate the size of your home folder in the General > Size section.  The Available size must be greater than the size of your home folder.

A few things to be aware of when using FileVault to encrypt your home folder:

  • Because Mac OS X is constantly encrypting and decrypting your home folder while you work,  you may notice slower performance when handling large files (movies, iPhoto libraries, etc.).
  • If you share folders from your computer, other users won't be able to access them unless you're logged in.
  • Some automations or scripts that require data stored in your home folder may not run.
  • Backup utilities, like Time Machine, may see your home folder as always changing, and this could slow down your backup. NOTE: Backups, either using Time Machine or manual backups, are not encrypted by FileVault, so keep them in a secure location.

Setting up FileVault on your computer
 

  1. In the menubar, click on the Apple logo > System Preferences.  Go to Security (or Security & Privacy) > FileVault.
  2. If the Security preferences pane is locked, click the lock icon in the lower left, and then type an administrator name and password for the computer (usually the account you login to the computer with).
  3. If the Security preferences pane shows that a master password hasn’t been set, click Set Master Password, and then type a password in the Master Password box.
  4. Your master password provides a second way for you to access your account if you should forget your regular login password.  Warning:Don’t forget your master password. If you turn on FileVault and then forget both your login password and your master password, you won’t be able to log in to your account, and your files and settings will be lost forever.
  5. Type the password again in the Verify box.
  6. Type a hint in the Hint box to help you remember the password.
  7. Click OK.
  8. Click “Turn On FileVault.” If you want to be sure your deleted files can never be recovered, click “Use secure erase.”
  9. Click “Turn On FileVault.”