n the context of Internet of Things security, Secure Boot refers to the process of authenticating a device’s firmware and operating system against a known secure cryptographic key placed on the device at the time of manufacture. This authentication occurs every time the device is booted to validate that the firmware or code being loaded is the legitimate version that was placed there by whoever produced it.
With Secure Boot, a bad actor who gains physical access to a device embedded in an IoT system or product would be unable to boot the device with their own modified firmware or bootloader, as this wouldn’t cryptographically match the secure key implemented by the manufacturer.
https://www.particle.io/iot-guides-and- ... cure-boot/