Electronic Thesis and Dissertation Repository


Doctor of Philosophy


Computer Science


Mark Perry

2nd Supervisor

Miriam Capretz

Joint Supervisor


Service Oriented Architecture (SOA) is an architectural style that builds enterprise solutions based on services. In SOA, the lack of trust between different parties affects the adoption of such architecture. Trust is as significant a factor for successful online interactions as it is in real life communities, and consequently, it is an important factor that is used as a criterion for service selection. In the context of online services and SOA, the literature shows that the field of trust is not mature. Trust definition and the consideration of the essentials of trust aspects do not reflect the true nature of trust online.

This thesis proposes a trust-based service selection solution, which requires establishing trust for services and supporting service selection based on trust. This work considers building trust for service providers besides rating services, an area that is neglected in the literature. This work follows progressive steps to arrive at a solution. First, this work develops a trust definition and identifies trust principles, which cover different aspects of trust. Next, SOA is extended to build a trust-based SOA that supports trust-based service selection. In particular, a new component, the trust mediator, which is responsible for trust establishment is added to the architecture. Accordingly, a trust mediator framework is built according to the trust definition and principles to identify its main components. Subsequently, this work identifies the trust information, or metrics, for services and service providers. Accordingly, trust models are built to evaluate trust rates for the applicable metrics, services, and service providers.

Moreover, this work addresses the trust bootstrapping challenge. The proposed trust bootstrapping approach addresses different challenges in the literature such as whitewashing and cold start. This approach is implemented through experiments, evaluations, and scenarios.