Securing XML-based Multimedia Content

Multimedia content delivery applications are becoming widespread thanks to increasingly cheaper access to high bandwidth networks. Also, the pervasiveness of XML as a data interchange format. has given rise to a number of standard formats for lIlultimedia, such as SMIL for multimedia presentations, SVG for vector graphics, VoiceXML for dialog, and MPEG-21 for video. Innovative programming paradigms (such as the one of Web services) rely on the availability of XML-based markup and metadata in the multimedia flow in order to customize and add value to multimedia content distributed via the Net. In this paper, we present. a general access control model for multimedia information that allows for expressing complex filtering conditions on a wide range of properties of multimedia data. Access control policies' syntax and enforcement is illustrated by applying the model to some of XML-based multimedia data formats for multimedia.