Consider, briefly, the unthinkable: Your Mac is stolen. What happens next?
You’ll lament losing the machine. If you didn’t back up your files, you’ll shed tears for the years of lost data. And then you might wonder whether the criminal might have stolen your computer not for the computer itself but for your data on the hard disk. Yikes!
Whole disk encryption is insurance against the last part of this nightmare scenario. When it’s enabled on your computer, all of the data stored on your hard disk is encrypted with XTS-AES 128 encryption. Not even the NSA or CIA could access the encrypted files on your hard disk without your account password.
This free data protection is baked into OS X with a feature ...