Secure storage and secure boot on your Mac mini
Your Mac mini includes the Apple T2 Security Chip, which provides the following security features to protect what’s on your computer and prevent unauthorized software apps from loading during startup:
Secure storage: Your Mac mini storage drive is encrypted with hardware keys to provide advanced levels of security. In the event of a catastrophic failure, data recovery may not be possible, so you need to back up your system to an external source. You can set up Time Machine or another back up plan to regularly back up the contents of your computer. See Back up your files with Time Machine in the macOS User Guide and the Apple Support article Back up your Mac with Time Machine.
Secure boot and Startup Security Utility: Support for secure boot is turned on automatically. It helps ensure that only legitimate operating system software is loaded on your computer at startup. See the Apple Support article About Secure Boot.
If your Mac mini doesn’t start up because it detects an untrusted component, it will start up from a secure recovery partition and automatically correct issues if possible. To learn more about the Startup Security Utility or to find out how to set other options, such as starting up from an external device, see the Apple Support article About Startup Security Utility.
Learn more. See the Apple Support article Mac computers that have the Apple T2 Security Chip.