MULTI-LEVEL, MULTI-DIMENSIONAL CONTENT PROTECTION

摘要

In one aspect of the invention is a method for a multi-level, and multi-dimensional scheme of content protection. Content having one or more attributes is encrypted using separate keys for each level of protection, where each level corresponds to an assurance of protection for each attribute. The content may be distributed to a number of environments having different levels fo protection by transmitting a base key commensurate with the environment's subscription level. The base key may then be used generate lower level keys for accessing content at a level of protection less than or equal to that subscribed to.