How to Secure Your Mac Data with FileVault
With FileVault, OS X can encrypt each user account, making it more secure. All the data associated with that Mac user is scrambled using the widely accepted AES-128 cipher. Using FileVault is an excellent idea to secure information if you store sensitive data and you travel with a laptop, or if many people have access to your computer.
Encryption slows hard drive access somewhat and may affect tasks that involve a lot of data, such as movie editing or Photoshop work. One compromise is to have two user accounts, one with FileVault for sensitive work and the other without FileVault protection for work where processing speed matters.
Log on as the user you want to turn on FileValue for.
If you like, you can turn on FileVault while creating a new account — you’ll see a check box to select.
Select System Preferences from the Apple menu, click the Security icon, and then click the FileVault tab at the top, if it isn’t already highlighted.
You see the FileVault setup window.
If you haven’t already, set a master password for your Mac by clicking the Set Master Password button.
A master password allows you to recover data from any FileVault user that has forgotten his password. Knowing the master password also lets you reset any user’s logon password.
Choose a password.
You can call up Password Assistant to help you choose this password by clicking the Key icon next to the password entry field. Because FileVault encrypts your home directory using your logon password, your account should have a high-security-level password.
If you need to change your logon password, select System Preferences from the Apple menu and click the Accounts icon. Change your logon password.
You should also log out and log back on to make sure that everything is working.
Return to the System Preferences Security screen and click the Turn On FileVault button.
Depending on how much data is in your home directory, the initial encryption process could take a while. If you’re working on your laptop, plug in the charger. If you already have sensitive info stored in your account, select the Secure Erase check box to ensure that OS X thoroughly obliterates the unencrypted data when it’s done encrypting.
When you log out of a FileVault account, OS X often asks your permission to tidy up and recover some unused space. Only say yes if you have time and battery power for the operation to complete. Otherwise, tell OS X to wait.