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–Multimedia computer systems are required to store, retrieve, and communicate objects comprised of mixed data types including images, text and voice. An important aspect of multimedia systems is the integration of elements retrieved from databases distributed across a network. Integration of object components requires consideration of the temporal(More)
— Proving ownership rights on outsourced relational databases is a crucial issue in today internet-based application environments and in many content distribution applications. In this paper, we present a mechanism for proof of ownership based on the secure embedding of a robust imperceptible watermark in relational data. We formulate the watermarking of(More)
— Sensor networks are designed with the assumption that nodes are willing to collaborate. However, the open collaboration of nodes introduces privacy and security issues. Therefore, ensuring privacy in wireless sensor networks is a challenging task. Based on a multilevel security paradigm, in this paper we present a hierarchical key generation and(More)
–Multimedia data often have time dependencies that must be satisfied at presentation time. To support a general-purpose multimedia information system, these timing relationships must be managed to provide utility to both the data presentation system and the multimedia author. In this paper we propose new conceptual models for capturing these timing(More)
A Generalized Temporal Role Based Access Control (GTRBAC) model that allows specification of a comprehensive set of temporal constraint for access control has recently been proposed. The model constructs allow one to specify various temporal constraints on role, user-role assignments and role-permission assignments. However, Temporal constraints on role(More)
—Multidomain application environments where distributed multiple organizations interoperate with each other are becoming a reality as witnessed by emerging Internet-based enterprise applications. Composition of a global coherent security policy that governs information and resource accesses in such environments is a challenging problem. In this paper, we(More)
As the demand for multimedia information systems increases and network technology provides the capability to handle multimedia data, effective communication and synchronization mechanisms are needed in a distributed environment to realize the successful retrieval , composition and presentation of multimedia objects. In this paper, we propose a specification(More)
The XML Role-Based Access Control (X-RBAC) specification language addresses multidomain environments' policy-specification needs. X-RBAC is based on an extension of the widely accepted US National Institute of Standards and Technology role-based access-control (RBAC) model. In addition to allowing specification of RBAC policies and facilitating(More)
T he Internet and related technologies have seen tremendous growth in distributed applications such as medicine, education, e-commerce, and digital libraries. As demand increases for online content and integrated, automated services, various applications employ Web services technology for document exchange among data repositories. Web services provide a(More)