Secure content distribution for digital libraries

Security is a very relevant aspect in the implementation of most digital libraries. Two important security issues in these systems are distributed access control and secure content distribution. This paper presents a system that provides these two features for digital libraries. The system is based on the combination of the use of an external authorization infrastructure, a software protection mechanism and a modular language to specify how access to the contents is controlled. The extensive use of semantic information makes possible the integration of such a complex set of subsystems.