An extended rights expression model supporting dynamic digital rights management

License often plays the role of an agreement between the user and the copyright owner. Rights expression language should provide a description of interactive mechanism and license negotiation to avoid the ambiguous transformation between REL and authorization protocols. By extending the ODRL to establish a digital rights expression model of appending, updating and aggregating license, the interactive license management mechanism can be described. In this paper, the supposed scheme can support fine-grained authorization, progressive or updating authorization and combination authorization to achieve dynamic rights management of digital content.