Security & Privacy
Secure Boot
ActivePublished
Key
innovation
A chain of trust cryptographically verifying each boot layer, blocking untrusted code from startup.
Category
Security & Privacy
Abstraction level
Building block
Operation level
DeploymentSystem
How it works
At startup, a hardware root of trust verifies the signature of the first boot stage; each verified stage checks the next. If a signature does not match (code is modified or not signed with a trusted key), boot is halted or switched to recovery mode.
Problem solved
If an attacker swaps the firmware or bootloader, they can take over the device before any OS-level protections start; trust must be verified from the moment of power-on.