The University of Texas at Austin

Security Awareness

Encrypting Your Files on a Mac

This procedure describes how to use FileVault to encrypt data in your Home directory on a Macintosh computer using Mac OS X versions 10.3.x and higher. The process creates a single, encrypted chunk of information that are unencrypted as you open them, rather than encrypting individual files or folders. Once you complete this procedure, you may notice that your computer slows down a bit as you open and close files. You should notice this less over time.

Be sure that you have set your Master Password.


If you turn on FileVault and then lose your login password and the Master Password, you will be unable to log in or access your encrypted files.

Before You Begin

This procedure works only if you selected the Mac OS extended (journaled) file system type option when you installed the operating system. If the system disk is set to "unix," you can't use FileVault.

You must be an administrator on your computer, or you must have an administrator’s help to turn on FileVault.

You may need to create some free disk space on your computer so that FileVault has enough space to complete the encryption process.


  1. Open System Preferences.
  2. Select Security.
  3. Click Set Master Password.
  4. Enter the Master Password.
  5. Enter the password again to Verify.
  6. Enter a Hint to remind you of your password.
  7. Click OK.
  8. Click Turn on FileVault. Read the message and confirm that you want to turn on FileVault. Enter your master password if you are prompted to do so.
  9. Close the Security window. You will be temporarily logged out of your computer while your home directory is converted to an encrypted disk image. This may take some time if you have a lot of files on your computer.
  10. Log back into your account.