Patent ID: 7590853
Filing Date: 2009-09-15
Classification: G06F,G06Q,G11B,H04L

Abstract:
1. A method performed by an electronic appliance comprising at least one protected processing environment, the method comprising the steps of: receiving a first load module and an associated first digital signature; receiving a second load module and an associated second digital signature; authenticating the first digital signature using a first cryptographic key; authenticating the second digital signature using a second cryptographic key; conditionally executing the first load module in a first processing environment of the electronic appliance based at least in part on a result of the step of authenticating the first digital signature, wherein the first processing environment has a first assurance level; and conditionally executing the second load module in a second processing environment of the electronic appliance based at least in part on a result of the step of authenticating the second digital signature, wherein the second processing environment has a second assurance level that is different from the first assurance level; wherein the protected processing environment is operable to impede tampering by a user of the electronic appliance with at least the step of authenticating the first digital signature and the step of authenticating the second digital signature.