Macintosh: turning on filevault protection
FileVault2 is an OS X utility that provides full disk, XTS-AES 128 encryption to help keep your data secure.
Installation instructions for FileVault2 drive encryption in OS X 10.7 or later
FileVault2 requires OS X Lion (10.7) or later, and OS X Recovery installed on your startup drive.
You will need the administrator password as well as the password for every user account that will have permission to unlock the hard drive.
Open System Preferences > Security & Privacy > FileVault
Click the lock to enable changes.
Enter the password for every user account that needs to be able to unlock the drive.
Any accounts not entered here will require an administrator or an allowed user to boot the machine for them. Once unlocked, the drive remains unlocked and available to all users, until the computer is restarted.
Record this key in a safe place that is not on the computer you are encrypting. You can email this key to yourself and email@example.com so that we have a record of it in case you need help.
without your password or this key there is no way to recover the files on you hard drive
Apple can also store your recovery key on their servers. Choose and answer 3 security questions if you would like them to do this.
Recovering your key from Apple will require contacting AppleCare and may have a fee for the service.
After restarting, your drive will begin encrypting as soon as you log in. You are able to use your Mac during this process.