Trust-Based Service Composition and Optimization

As an important method for creating value-added services by composing existing services, Web service composition technology has attracted an increasing attention in recent years. Most current service composition and optimization methods utilize quality of service (QoS) attributes to decide which concrete services to invoke. However, trust which is of critical importance to service composition processes is ignored in these methods. To solve the problem, a trust-based service composition and optimization method is proposed in this paper. First, the trust of service composition is defined in terms of the trust of component service selection processes, composition processes and optimal binding plans. Second, a framework is proposed to guarantee the trust of service composition. In the framework, the trust of component service selection processes is guaranteed by filtration, and the trust of composition processes is guaranteed by interface-based service clustering methods. In order to find a trustworthy binding plan, a trust evaluation method is also included in the framework. Finally, a case study based on real Web services is presented, and the experimental results show that the framework can effectively guarantee the trust of service composition and optimization processes.