Research On Security And Reliability Of Web Services Based Business Process

With the development of distributed computing, Web services have gradually become the standards of constructing distributed computing platform and service framework of modern enterprise. Web services are dynamic, platform-independent, open and loosely coupled, thus facilitate collaboration and information sharing among information systems and enable organizations to dynamically select services and build business processes according to their respective targets. For the same function requirement, there may exist plenty of services with different quality of service. Thus quality of service becomes a factor which needs to be considered when selecting Web services. As a particularly important aspect of quality of service, reliability is highly regarded. Meanwhile, from the perspective of security, in the execution of business process in which many persons or organizations are involved, we need to consider the security constraints relationships between the activities of the process. Therefore, how to select appropriate services under the premise of the satisfaction of security constraints becomes a key issue for services selection.Many current researches disscuss Web services selection based on the quality of service. By considering the restrictions on quality parameters such as response time, price, and reliability etc., local or global optimization of quality of service on compositive services are achieved. However, most of them did not consider the security requirements of organizations on compositive services. As a prerequisite to ensure the proper execution of business processes, security constraints must be considered during the process of services selection.To address the above problems, this paper does some research on the services selection of business process and gives careful analysis on the factors which should be considered in the selection process and the influence these factors have on the execution of business processes, and proposes corresponding solutions, the main contributions are:Aiming at the neglect of security constraints in current research on services selection, we present a services selection method for the activities of business process. We give the formal schema of business processes, and discuss the considered factors, namely quality of service and security constraints when selecting services. In the aspect of quality of service, we mainly consider response time, price, reliability and reputation these four parameters. In the aspect of security constraints, we mainly consider separation of duty and binding of duty constraints. In addition, we give the formal definition of services selection for business processes and linear programming-based solution, describe in detail the corresponding objective function and constraints conditions of linear programming problem, i.e. the expression of the quality of service constraints and security constraints).In order to better guarantee the execution of the entire business process, we present a method of dynamic Web service selection based on security and reliability of business process. This method takes fully into account the influence the reliability of atomic services has on the performance of business processes. It ensures to select services dynamically based on the execution reliability of the configurations under the satisfaction of the security constraints of the organization. We use Markov chain to model the services composition of business process. In the process of composition, we do the execution path pruning on the composition based on security constraints, and then realize dynamic services selection based on the reliability of atomic services and the configuration in the pruned Markov chain.In this paper, the logical structure of Web service composition based on business process and BPEL-based framework for business process management are given. We give an introduction of corresponding model functions. Meanwhile, the experimental results show the proposed methods are effective and feasible.