OPA: Onion Policy Administration Model - Another approach to manage rights in DRM

Digital Rights Management frameworks (DRM) aim at protecting and controlling information contents widely distributed on client devices. Using a license, the content owner specifies which rights can be rendered to end-users. Basically, only the content owner must be able to define this license, but some DRM models go further. In superdistribution scenario, the content owner does not directly manage enduser’s rights but rather delegate this task to a third-party called a distributor. Nevertheless, this distribution cannot be done without any control. In existing approaches, the content owner restricts the license issued by the distributors. In this paper, we provide a new approach, called the Onion Policy Administration approach (OPA). Rather than restricting licenses issued by the different distributors, OPA aims at controlling which rights are finally rendered to end-users. The main idea of OPA is to have a traceability of the content distribution. The content must keep track of all third-parties it crossed in the distribution chain. In this case, everyone can distribute the content and define a new license without any restriction. In these licenses, the content owner and distributors specify end-user’s rights. Using the content traceability, the DRM controller can gather all licenses involved in the distribution chain and evaluate them. In order to be rendered, a right must be allowed by both the content owner and all distributors involved in the distribution chain.