Modeling and implementation of a digital rights management system based on multilevel content distribution model

Abstract

The widespread use of the Internet has led to the problem of intellectual property and copyright. After a content item is downloaded, no further protection is provided on that content. DRM technologies have been developed to protect digital content items and their related rights. DRM technologies can be defined as a set of technologies that protect the copyright owner’s rights through enforcements, approximate current and future content distribution models, and support licensing models for content consumers. In this thesis, we examine the IMPRIMATUR model and propose an extended IMPRIMATUR model by addressing two issues with the IMPRIMATUR model: (1) the question of trust in the distribution entities, (2) the lack of capability expressing multiple steps of content/rights ownership. To address the trust issue, we introduce a new entity called clearing center operated by a trusted third party. To address the second issue, we describe our new model called multilevel content distribution model to model the real world situation that content and rights ownership go through multiple steps of distribution among the media distributors. To formally describe the multilevel content distribution model, we define a rights model and a rights protection system. We identify safety conditions to ensure that a rights protection system is safe in the sense that all the rights assigned at previous steps are preserved at the following steps. We also present rights-related algorithms to enforce the safety conditions. A major contribution of this thesis is proofs of safeness, soundness and completeness of the proposed model. These proofs respectively mean that the safety conditions keep any rights protection system safe, every rights instance generated in the proposed model satisfies the safety conditions, and the proposed model can generate all possible safe rights instances. Furthermore, we develop a new DRM architecture based on our extended IMPRIMATUR model. We discuss the differe...