Dynamic Collaborative Trust Model Based On Pervasive Computing

In the pervasive computing mode, all kinds of computing devices and sensor node equipments is coordinating with each other to seamless integrate the physical space and the information space, and merge into a providing active information service of intelligent information space. It is because that pervasive environment is a highly mobile, distributed open information system, involving a large number of technologies for network. And pervasive computing has paid more attention on the role of trust than traditional computing. At the same time, it makes a higher requirement for the security mechanisms of the system. As a result, this paper proposes a kind of trust evaluation model which applies to the universal environment for dynamic collaborative, evaluate the corresponding trust level that between the entities, who has information interaction, thus, the pervasive computing system can make an appropriate service strategies.This paper presents the model into trust evaluation module and risk evaluation module. The former has assessed the subject which restricted by various trust factors, using the fuzzy comprehensive evaluation method based on the cloud theory to describe and measure the fuzziness and the uncertainty existed in trust, and made the qualitative assessment into the quantitative evaluation. It is really suitable for solving the uncertain problems, because it provides effective data basis for the pervasive computing system making the right trust decision. In the risk assessment module, combining qualitative analysis based on fault tree analysis and quantitative calculation based on the information entropy method, has analyzed all levels of the different risk factors of influence weighting, calculated the total risk of target system, solved the conflict between the subjectivity and objectivity in value-at-risk. Finally, through comparing to the traditional trust evaluation model with the results of simulation experiments, it reflects that this dynamic collaborative model improves the confidence level and the rate of information exchange, and has a great advantage in the uncertainty embodies of confidence measure and the credibility evaluation of the system. So that this model can effectively assess the confidence level of pervasive service, but it is sure that this models sill needs to be improved and has a lot of room for improvement.