Study Of Trust Model Based On Sliding Window In Grid

Grid is a new network computing platform which developed rapidly after the internet, it enables the sharing of resources, and provides users with integrated services. However, it requires much safer environment than the traditional network because the feature of large-scale, distributed, heterogeneous and dynamic grid computing makes the environment very complex. Security is the key issue of grid computing technology, and the problem of trust is the core that people must face when we solve the grid security problems.So it is necessary to propose an effective trust model as we do the research about the trust.Firstly, the paper proposes a modified sliding window-based trust model in grid which called SWTrust through the study of existing classical trust model. The entire grid system is divided into several independent self-governing domains, and increase the autonomy of the domain by setting the inter-domain and the out-domain trust agents, and use two different approaches to deal with trust relationships between domains, reduce the computational complexity of the trust. Taking into account the impact of time on trust, introduce a sliding window for each grid node, it will solve the problem of trust in the decay over time through the window of sliding, making assessment of the results more accurate.Secondly, because the trust evaluation mechanism for existing trust can not be satisfactorily solved the problem of the decay of time, construct a time correction function to correct the trust, and propose a trust evaluation based on sliding window method to set a dynamic sliding window, assess trust for the node of the grid by adjusting the window size and moving the window, update the information timely, it will get the most accurate trust of the present time, and general trust is calculated by the direct trust and recommendation trust with the weighted average, and amend with the time correction function, reflecting the global nature of trust.Finally, designing a file sharing systemypical in typical grid environment by simulation software GridSim, demonstrating and analysing the SWTrust trust model designed in this paper from the aspects of effectiveness and accuracy of the model.