Rights violation detection in multi-level digital rights management system

A multi-level digital rights management (DRM) system consists of owner, multiple levels of distributors and consumers. The distributors and consumers are given redistribution and usage rights using redistribution and usage licenses respectively. However, both redistribution and usage licenses can be violated by a malicious distributor/consumer to bypass the permissions and constraints in them. Thus, it is required to detect such violations. In this paper, we deal with the redistribution rights violation using a process called license validation. The problem of validation becomes complex when there exists multiple redistribution licenses for the same content with the distributors. In such cases, large number of comparisons may be needed and it may become difficult in real time in a large and distributed multi-level DRM system. Hence, we propose a bit-vector transform based license organization technique to do the validation efficiently. The proposed license organization method is compatible with the DRM related tasks such as license revocation and constraint range revocation. Mathematical analysis and experimental results show that the proposed license organization technique can do the validation efficiently.