Protection and composition of crossmedia content in collaborative environments

A large range of new applications are appearing nowadays on the Web in which content and data produced by single users or groups are going to be adapted, composed and aggregated and then redistributed in other forms to other users and/or groups. In this context, the management of intellectual property rights (IPR) of the users collaborating in authoring and composition activities have to be preserved. In this paper we adopt an MPEG-21 representation of digital contents and propose a system that supports the users in their composition that takes into account the permissions of access/composition/modification that each single user or group can exercise on them. In our environment, users can retrieve digital content and data, check the authoring privileges that can be executed on the component resources to generate composite and aggregated contents, and verify the situations in which the composition can hide some privileges that exist in the original contents. When the user holds the privileges for the composition, a license can be automatically generated for the composite content that preserves the rights the user/group holds on the components. This environment supports collaboration among users belonging to different organizations that would like to work together in the realization of non trivial content/data aggregation processes.