One of the most valuable changes in Mac OS X 10.7 “Lion” is a complete overhaul of FileVault, Apple’s disk encryption system for protecting private data such as stored pictures, emails, documents and home movies.
In Mac OS X 10.4 and 10.5, FileVault could only be used to encrypt the “home folder” for each user, and it was widely criticized for a number of implementation flaws and security issues.
With 10.7 “Lion”, Apple intends to solve some of these flaws and significantly enhance security and privacy by turning FileVault into a disk level encryption system, not only for the main filesystem, but also for any external drive a user wants to protect with encryption.
While Apple is not the first to implement full system encryption, anyone running 10.7 will be able to use it, compared to Windows where an Ultimate or Enterprise edition of the operating system is needed to enable Microsoft’s system encryption feature called BitLocker (Truecrypt is a free alternative). Read more