I recently purchased a secondhand MacBook Air for work purposes; the laptop was shipped to me with a fresh install of OS X. I do not know the prior owner or what they used the laptop for, and thus I need to verify that all software and data on the solid state drive is both erased and irrecoverable before setting up a fresh OS X install.
I plan to do the following:
Encrypt the drive currently holding the placeholder OS X system using Filevault 2 and a strong password.
Reboot to an OS X install thumb drive, and erase the hard drive using Disk Utility. I assume this will securely erasing the FileVault key, thus rendering the old data impossible to decrypt.
Reinstall Mac OS X over the old (erased) encrypted volume, and set up FileVault 2 to encrypt this new install.
Is this sufficient to ensure that no relic software or hard drive data from the old drive owner is recoverable?