"Secure boot" is a technology described by recent revisions of the UEFI specification; it offers the prospect of a hardware-verified, malware-free operating system bootstrap process that can improve the security of many system deployments. Linux and other open operating systems will be able to take advantage of secure boot if it is implemented properly in the hardware. This document is intended to describe how the UEFI secure boot specification can be implemented to interoperate well with open systems and to avoid adversely affecting the rights of the owners of those systems while providing compliance with proprietary software vendors' requirements.