The FileVault option in macOS is a fantastic way to enhance the security of your data at rest. It’s full-disk encryption (FDE), meaning that your entire startup volume is locked away when macOS is shut down (not just sleeping) using strong encryption. Without the password that unlocks an account on your Mac that’s authorized to log in with FileVault, there’s no effective way to bring that computer to life.
That’s a problem, however, if you forget the password to all the authorized account or, in some cases I’ve received a few emails about, something goes wrong and the Recovery Disk—used both for “cold start” logins to macOS and to diagnose problems on your startup volume—demands a login that doesn’t work.
