Based On Cloud Model In P2p Network Trust Evaluation Research

With the rapid development and wide application of the P2P network, it has become a hottopic in the field of computer research. For the characteristics dynamic, heterogeneous andautonomous of P2P networks, malicious nodes that provide false information one after another,a very serious impact on the operation of the network comes out. Therefore the P2P networksecurity issues have also been put on the agenda, which becomes an urgent problem. How tobuild trust model in the P2P network and effective management on nodes is an important topicin P2P network research. Starting from the issue of trust in P2P networks, we proposed trustevaluation method based on cloud model.The cloud model is built on the basis of fuzzy set theory and probability theory byAcademician Li Deyi, which is the core component of cloud theory. This model takes a specificstructure operator to achieve conversion between qualitative concept and its correspondingquantitative expression. The cloud model can effectively express fuzziness, randomness, andassociation in the subjective trust. Compared to the other confidence expression in themathematical method, the cloud model can provide more valuable and more comprehensiveinformation. Build trust evaluation model based on cloud model in the P2P network hastheoretical and practical significance for problems which do not adequately describe theuncertainty of trust in most of the trust evaluation model.The trust zone of the nodes in the P2P network is divided into two aspects of the reputationtrust and transaction trust by Cloud model, which separately adopts evaluation cloud andfeedback method to trust evaluation. Takes Cloud model as the main tool to quantify theevaluation node and trading experience, a trust cloud evaluation model based on twodimensions is further designed. We present specific calculation methods for the reputation oftrust based on trust cloud In P2P networks reputation of trust, which, by the average trust statusof the nodes reflected by the expectation Ex to make trust decision, the other two figurescharacterization are described uncertainty of trust. Compared to a single representation of thedata of the trust, the method maximize reflect the trust uncertainty, has a great advantage.In computing transactions trust of P2Pnetwork nodes ,the paper also gives a specificcalculation method for recommended trust based on trust cloud, which can effectively identify recommended node of malicious or behavior instability. On the other hand, we also giveselection strategy of trading nodes based on trust cloud in the P2P network, which can solve theproblem of priority on high trust value and stability of the trading behavior of the peer to selectand how to choose the node of the same trust.Finally, in a typical P2P network file sharing system for experimental analysis, the resultsdirectly reflect the model of objectivity and accuracy, and provide a basis to select the reliabletrading node in the P2P network.