A Trust Management Model Based On The Radial Projection Algorithm In Grid

As a core technology of next-generation Internet, the function of grid technology is to integrate the computing resources and others which is geographically widely distributed and heterogeneous system, in order to that the high performance can share resources and work together on the virtual environment. The grid as a hardware and software infrastructure provides a single virtual platform for computing and managing data. The emergence of the grid technology provides the new perspectives, new ideas and new technologies for information system. The application of grid has developed from the initial high performance scientific computing to today’s business fields, such as education, astronomy, medicine and so on. Because the grid is based on Internet platform and inherited the features of large-scale, distributed, heterogeneous, dynamic and scalable, it has some security issues taken from traditional network and trust issue belonged to the distributed systems. The trust issues in the grid are resolved main through the establishment of the trust management models.Trust is the basis for the trust management, and the trust management model is the framework for creating and managing the trust, mainly included confirming the property, calculation and assessment of trust. Existing trust management models are divided into objective and subjective trust management model. The entities in objective trust management model verify the level of trust for other entities by using public key technology, and the entities in subjective trust management model assess whether an entity is trustworthy by observing the behavior of the entity.This paper focuses on subjective trust management model. The trust relationship between entities is specific quantitative in subjective trust management, and the assessment of trust is got by records of the interaction between entities, as well as direct observation of the behavior or advices of other entities. Currently, the researchers have proposed many trust management models to get the trust value, mainly based on Bayesian theory, on subjective logic, on evidence theory, on fuzzy logic, on gray theory and on gray prediction. Generally, the trust value is predicted by the GM(1,1)model in trust management model based on gray prediction. But GM(1,1) model is applicable to a strong exponential sequence which can only describe the monotonous process of change. It has some limitations for the time-varying trust management system.For the lack of GM (1,1) model in the predicting trust value, a trust management model based on the radial projection algorithm is proposed. In this model, the recommendation credibility degree and risk factor are defined, and the formulas of transaction amount, correlation factor, attenuation factor and continuous reward factor are given, and the public storage area used to save nodes’computation and storage space is introduced. The simulation and analysis results show this model not only improves the prediction accuracy of trust to meet universality and scalability, but also enhances the ability to distinguish between nodes of different acts, which can accurately identify malicious nodes, to ensure effectiveness and robustness.Then for the trust problem in the P2SP network, the model is put into P2SR.A preliminary concept of trust management model under P2SP environment is provided as the further research work.With the development of the Internet, "cloud computing" platform becomes the new trend of the development for the grid. The "cloud security" involved in "cloud computing" has become a hot issue, too. Finally, our paper takes a constructive thinking for the "cloud killing" in the trust management model.