Research And Design Of DRM System Based On SPKI

With the development of network and digital technology, Digital rights management (DRM) is becoming a key enabling technology to protect intellectual property of digital contents, control their dissemination and usage. At present there are already many DRM application systems. The existing DRM systems use digital-license to protect intellectual property of digital contents mostly, this way has the authorization mechanism inflexible, user privacy exposure easy and so on. For these issues, SPKI mechanism was introduced and a new DRM system based on SPKI was proposed in this thesis.The system's authorization policies and authorization realization were studied, and the system's architecture,process flow and key modules were designed, Furthermore some realization work was done.The thesis makes the following contributions:1,The origin, the basic concept, the basic technologies of DRM were studied, and the existing DRM system's compositions, process flow as well as issues were analyzed particularly. SPKI mechanism and UCON model were also studied, the authorization implementation of SPKI and policies expressed by UCON model were the emphases.2,A new usage control model of the DRM system based on SPKI was proposed and used to express policies of the system, the definition of policies and their application examples were given. The circulation model of digital content in the system was designed and different distribution modes were contained in the model, the question how to use SPKI authorization certificate to implement authorization in different distribution mode was discussed, and the extended SPKI authorization certificate's structure and its description by XML were given.3,The requirement of design for DRM system was analyzed from both the functional and secure perspectives, the principle of design was also formulated, and design goal was established. Then revolving around the design goal, the architecture,the process flow and key modules of the DRM system based on SPKI were designed.4,Some key functional modules of DRM system based on SPKI were implemented simply. In addition, the system designed was analyzed detailedly and its characteristics were summarized.The DRM system based on SPKI proposed in this thesis is an innovation. The DRM system designed makes full use of characteristics of SPKI to overcome flaws in authorization and privacy protection of existing DRM systems while realizes protection of digital content copyright effectively.