Block, Inc.
Update policy-based anti-rollback techniques

Abstract:

Techniques for implementing policy-based anti-rollback techniques on a computing device are described herein. As an example, a remote service may provide the computing device with a boot policy which indicates, for each boot stage of a software bootloader process, what software versions are permitted to execute. Prior to providing the computing device with the boot policy, the remote service may sign the boot policy with a private key, and include of an identifier corresponding to the computing device. At each boot stage of the bootloader process, components of the computing device may verify, using a public key, that the boot policy was signed with the private key, and that the boot policy corresponds to the computing device. After verification, the components may analyze the boot policy to determine whether each boot stage is permitted to execute a software version and boot to the next boot stage.