Privacy Preserving DRM Solution with Content Classification and Superdistribution

Digital rights management (DRM) is indispensable to prevent various kinds of illegal content usage. However, personal privacy is vulnerable for disclosure when the detailed consumption reports are collected by the service provider to charge consumers. Usually those kinds of data could apparently render the work and rest schedule and reveal the hobby of certain customers. Although it is claimed that all of the private data should be protected without the fear for disclosure, it had better to avoid generating those sensitive records. Therefore, a new DRM solution is proposed to provide an obscure consumption report to the service provider with content classification and superdistribution while maintain the normal charge system. In addition, a novel key management scheme is presented to support the above solution. In this scheme, multiple encryption keys and decryption keys in the same content level are designed through a specific algorithm. Distributing a unique decryption key set to each user facilitates the tracing in case of deliberate key leakage and then assists realistic deployment of the DRM system.