Binary Relation Database BIRD: Issues of Representation and Implementation

This thesis presents a study of two issues, integrity and homogeneity of information representation, within the area of databases. Treatments of these issues were studied within the standard and semantic database models, leading to the proposal of a new model, the Binary Relation Database, BIRD. The BIRD model uses the binary relationship as the basis for the representation of all database data and meta-data. The inadequacy of integrity definition faculties within current database technology areelaborated in this thesis and were taken into account in the BIRD system. The effects of inhomogeneity of database data and meta-data in current databases are described and the benefits of the homogeneity of information representation in BIRD demonstrated. BIRD was implemented as a prototype database system; using Modula-2, - the implementation and subsequent evaluation of the system are included in this thesis. A simple user menu driven user interface to BIRD was constructed, - the user may manipulate information at any conceptual level in the system in a homogeneous manner. The user is free to manipulate information from any conceptual level at anytime; - BIRD ensures that the database is returned to a consistent state before the next operation may take place. The new model proposed in this thesis fulfilled its objectives, - suggestions for further and implementation oriented work are presented at the end of the thesis

CRiBAC: Community-centric role interaction based access control model

As one of the most efficient solutions to complex and large-scale problems, multi-agent cooperation has been in the limelight for the past few decades. Recently, many research projects have focused on context-aware cooperation to dynamically provide complex services. As cooperation in the multi-agent systems (MASs) becomes more common, guaranteeing the security of such cooperation takes on even greater importance. However, existing security models do not reflect the agents' unique features, including cooperation and context-awareness. In this paper, we propose a Community-based Role interaction-based Access Control model (CRiBAC) to allow secure cooperation in MASs. To do this, we refine and extend our preliminary RiBAC model, which was proposed earlier to support secure interactions among agents, by introducing a new concept of interaction permission, and then extend it to CRiBAC to support community-based cooperation among agents. We analyze potential problems related to interaction permissions and propose two approaches to address them. We also propose an administration model to facilitate administration of CRiBAC policies. Finally, we present the implementation of a prototype system based on a sample scenario to assess the proposed work and show its feasibility. © 2012 Elsevier Ltd. All rights reserved