Abstract: The present invention discloses an apparatus and method for defining and enforcing rules of transition between two security domains, e.g., a transport domain and a persistent security domain. In turn, a border guard, e.g., a security device, is provided between these two domains that enforce rules for transition between the two security domains. This novel approach of defining a transport domain and a persistent security domain simplifies the classification of the digital content and its movement through the system. Namely, the border guard once established between the two systems can enforce DRM rules associated with how contents are moved between the two domains.

Abstract: The present invention discloses a system and method for providing a secured system time reference to a subscriber device, e.g., a set top box or a receiver. In one embodiment, the system time reference is provided in a secure system time message that is broadcasted to a plurality of subscriber devices. Each subscriber device has a security device or software application that is capable of determining whether the received system time reference is legitimate. If the system time reference is determined to be legitimate, a local time reference is synchronized with said received system time reference.