Patent ID: 7415620
Filing Date: 2008-08-19
Classification: G06F

Abstract:
1. A method implemented in a subscriber unit for establishing a chain of trust between the subscriber unit and a content provider, the subscriber unit having a central processing unit (CPU) and an operating system (OS), the CPU having a pair of private and public keys, a manufacturer certificate supplied by a manufacturer of the CPU, and a software identity register that holds an identity of the operating system, the method comprising: submitting a request to the content provider, the request specifying a particular content; receiving, from the content provider, a challenge nonce generated at the content provider; forming an OS certificate containing the identity from the software identity register, information describing the operating system, the challenge nonce, and the CPU public key and signing the OS certificate using the CPU private key, wherein the forming comprises forming the OS certificate with one or more items from a boot log containing identities of software components that are executing on the CPU; passing the OS certificate and the CPU manufacturer certificate to the content provider for the content provider to evaluate the OS certificate and the CPU manufacturer to determine whether to reject or fulfill the request.