Multimedia Access Control Using RDF Metadata

Abstract

Abstract. The Synchronized Multimedia Integration Language (SMIL) [Aya01] is an W3C[W3C03] specification for authoring multimedia documents. Although SMIL has XML like syntactic constructs, unlike XML, SMIL compositions have an intended interpretation stemming from intuitive notions of playing out many media streams relative to each other. Thus, more than one SMIL syntactic expression can represent a multimedia composition with the same intended semantics. In this work we propose a normal form for SMIL objects that allows to specify security policies that are independent of representational syntax. We also show how to represent access control and QoS polices applicable to multimedia compositions by decorating SMIL compositions with RDF [KC03] statements. Our RDF statements are based on an RDF structure tailored to represent known security paradigms such as Discretionary, Mandatory, and Role-Based Access Control. Once the security paradigm is chosen and the SMIL document is decorated with security and QoS specifications, we show how to create secure views of the SMIL document. We call these views secure normal forms. Next, we show how a secure multimedia server can use these views to provide secure runtime environment.

SecureCloud: Towards a Comprehensive Security Framework for Cloud Computing Environments

“…While XML has been adopted as the preferred language for information sharing it has been found inadequate for describing information semantics [9], [10]. RDF, on the other hand, provides a facility for describing semantics by supporting element attributes and properties description [8]. Although semantics can be captured using RDF, representing relations between the various concepts is essential for facilitating semantic integration of policy information within interacting domains.…”

Creating non-decomposable stream bundles in multimedia web services using uSMIL

“…A release control for SMIL formatted multimedia objects for pay-per-view movies on the Internet that enforces DAC is described in [14]. RDF [16] based security architectures for multimedia security [12] and authorization models for secure digital libraries [8] have also been proposed. A secure and progressively updatable SMIL document [15] is used to enforce RBAC and respond to traffic emergencies.…”

“…Although specified using XML-like syntax, SMIL trees do not convey the informal runtime semantics intended of multimedia synchronization. In order to precisely specify them [11,12] formalized a semantics for SMIL trees using media intervals. Naturally, in that semantics any media presentation can be specified as a parallel playout of sequence of media frames.…”

“…This can also be achieved using SMIL syntax, referred ro as the normal form of a SMIL specification. [11,12] provides some basic algebraic identities that can be used to rewrite a SMIL tree into its normal form. We now recall these definitions.…”

“…The proof is given in [11,12]. We now use a basis mapping to define operational semantics of any SMIL specification as follows.…”