DRM system for multiple cascaded business operators

DRM (Digital Rights Management) is a basic tool to protect digital content from unauthorized using, which is regarded as one of the most important mechanisms in content industry. In a basic scenario of DRM application, there are a couple of roles are involved, named Content Provider (CP), Service Provider (SP) and consumer Device. CP makes the digital content and distributes to SP, who will then deliver the content to user through its network. In current content delivery architecture, CP has no control of the content after it is distributed to SP, which means the SP may use the content in a way that is not consistent with the agreement between CP and SP. To solve this problem, in this paper, we propose a multiple layers DRM system to protect the interest of both CP and SP. That is, the CP can protect the content from the SP and also make sure CP´s policy to be enforced in the client. In this way, the SP may operate different business model with end users and also ensure the CP´s policy to be enforced.