Securely Signing Configuration Settings

Techniques are disclosed relating to securing computing devices during boot. In various embodiments, a secure circuit of a computing device generates for a public key pair and signs, using a private key of the public key pair, configuration settings for an operating system of the computing device. A bootloader of the computing device receives a certificate for the public key pair from a certificate authority and initiates a boot sequence to load the operating system. The boot sequence includes the bootloader verifying the signed configuration settings using a public key included in the certificate and the public key pair. In some embodiments, the secure circuit cryptographically protects the private key based on a passcode of a user, the passcode being usable by the user to authenticate to the computing device.