Your 24-inch iMac with Apple M1 chip provides the following security features to protect what’s on your computer and prevent unauthorized software apps from loading during startup:
Secure storage: Your 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 files to an external source. See the Apple Support article About Startup Security Utility.
System integrity: The Apple M1 chip in your 24-inch iMac verifies that the version of macOS software loaded during startup is authorized by Apple, and continues behind the scenes to protect the authorizations established for macOS. This makes it harder for malware or malicious websites to exploit your iMac.
Data Protection: In addition to the default storage drive encryption in the iMac, third-party app developers can use file-level encryption to better protect sensitive data, without impacting system performance.