Trust Management In IVCE

As an outcome of the interactions of communication and computing technologies, Internet has become a part of our daily life after its 40 years'growth. With the popularity of internet applications, there are vast kinds of resources over Internet, including information resources, application resources and computer devices. Internet resources have become a part of resources of human societies. However, nowadays there are prominent and urgent problems in the sharing and utilization of Internet resoures. First, the usage ratio of sharing resources in the Internet is significantly low while a large number of resources are abused; secondly, there lacks a reliable security assurance for distributed interaction. To meet these challenges, a new platform as Internet-based Virtual Computing Environment (iVCE) is proposed. The initiative of iVCE aims to provide the end users and applications with a harmonious, trustworthy and transparent integrated computing environment which will facilitate sharing and collaborating of network resources between applications. Trust management is an elementary component for iVCE which aims to provide the assurance of safety, dependence and credibility for the on-demand aggregation and autonomic collaboration behavior of resources to create a secure and harmonious computing environment.Because of the open and incontrollable nature of internet resources, the iVCE has the dynamic and inconsistent characteristics of on-demand aggregation and autonomic collaboration. Thus the traditional security mechanism which often needs central-based official certificate is unable to meet the requirement of iVCE. In iVCE, there is no predefined authorizing or authorized relationship between service provider and service requester. Therefore trust is a prerequisite for interactions, which is similar to human behavior of estimating the extent to which one party is willing to depend on somebody in a given situation with a feeling of relative security, even though negative consequences are possible. In general, trust is subjective, context dependent, personal experience based, reputations related, and recommendation aggregated. The aim of this thesis is to construct the trust management framework for iVCE based on the notion of human trust, to study the selection of proper service provider, trust calculation, risk evaluation during interactions of autonomic elements, to design an incentive mechanism based on reputation management. Our main achievements are as follows:1. A trust management framework is proposed based on the notion of human trust according to characteristics of iVCE. It includes three layers as Identity Management System (IMS), Evidence Management System (EMS), and Trust Calculation System (TCS). Because the trust management system is implemented on the level of the autonomic element, the autonomic element is able to identify the behavior and identity of unkown entities, and to make autonomic trust decision based trust calculation and risk evaluation. Such mechanism does not need a centralized authority and predefined authorization; therefore, it can match the requirements of security mechanism in iVCE.2. A Bayesian analysis-based trust model is presented which aims at the requirement for the trust management to be subjective, historical evidence based and context dependent. The model gives a solution for selection of proper service provider, trust calculation and recommendation trust evolutions.3. A risk evaluation model is proposed based on FMEA analysis. The model is context dependent and historical interactions related.4. An aggregation mechanism for virtual commonwealth based on global repution management is proposed. Reputation drives autonomic elements which provide positive interations to join virtual commonwealth with higher reputition for more reliable interations, thereby it facilitates the stabilization of iVCE; on the other hand, autonomic elements which provide negative interactions will be abandoned by virtual commonwealth, and gradually isolated, thereby it stimulate autonomic elements to improve the quality of service. In general, the reputation incentive mechanism promotes autonomic elements to be willing to provide positive interations.