Secure Boot is a feature exclusive to the iMac Pro that lets your machine verify that it is booting a legitimate or supported version of macOS. Used through the iMac Pro's Startup Security Utility, Secure Boot offers different levels of protection based on your needs.
Secure Boot comes with three settings:
- Full Security - Using this setting, the only operating systems that can boot on your iMac Pro are the version that is currently installed or a signed OS trusted by Apple.
- Medium Security - Any signed version of an operating system trusted by Apple can run on your iMac Pro.
- No Security - No requirements are enforced on on bootable operating systems.
Here's how you can use and manage Secure Boot on your iMac Pro.
How to use Secure Boot on the iMac Pro
To use Secure Boot, you'll need to enter the iMac Pro's Startup Security Utility immediately upon startup of your machine.
- Immediately press Command (⌘) and R at the same time right after turning on your iMac Pro.
- Click Utilities in the Menu bar in the Utilities window.
- Click Startup Security Utility.
- Click Enter macOS Password when asked to authenticate.
- Select an administrator account.
- Enter the account password.
- Choose Full Security, Medium Security, and No Security.
- Close Security Startup Utility.
- Click the Apple icon in the Menu bar.
- Click Restart to restart your iMac Pro with your new security settings in place.
Questions
If you've got any further questions about using Secure Boot on the iMac Pro, ask away in the comments.

Review — Fire Emblem Warriors: Three Hopes is a fun but repetitive return
Fire Emblem Warriors: Three Hopes allows players to revisit the same characters from Three Houses. However, it's very different and will only be enjoyable if you understand that going in.

iOS 16 makes Shortcuts "much easier" for developers to adopt
At WWDC, Apple introduced updated developer tools for integrating with the Shortcuts app. We asked three app developers about their thoughts on the changes.

Review: Apple Studio Display isn't perfect, but offers surprising goodies
It has many drawbacks, but the Apple Studio 5K Display is worth considering for those who may be looking for an Apple-branded display.

Don't like Apple's Magic Keyboard? Try these alternatives.
Do you like the look of Apple's Magic Keyboard, but want something a little different? Here are the best Magic Keyboard alternatives.