Patent ID: 8572411

Claim:
A method comprising: receiving electronic content at a first user's electronic appliance, the appliance comprising a secure processing unit, the electronic content having been sent from a second user's electronic appliance, wherein the secure processing unit prevents unauthorized access to its components by selectively allowing data originating outside of the secure processing unit to cross a tamper-resistant security barrier and enter the secure processing unit, and by processing the allowed data within a compartmentalized secure execution space that prevents less trusted data from modifying more trusted data; receiving, at the first user's electronic appliance, control information associated with the electronic content, the control information indicating that the electronic content may be used only in one or more authorized ways; and using a software application running on the first user's electronic appliance to enable the first user to make at least one use of the electronic content in accordance with the control information, wherein the software application is configured to be resistant to attempts by users of the first electronic appliance to use the electronic content in unauthorized ways, and wherein the software application is operable to communicate with the secure processing unit to obtain information necessary to decrypt the electronic content.