Survivablity Mechanisms And Methods Of P2P Network Under Asymmetric Information-sharing Environment

With the increase of Internet penetration and user demand on the access to cybersources, achieving a nationwide sharing source is an inevitable trend. A new asymmetricnetwork architecture for ubiquitous information sharing is proposed to achieve a highefficiency and low cost resource sharing. As a new network structure, its security is avery prominent problem. Thus, it is urgent to resolve the potential difficulties to ensurea safe and reliable service.This article presents the research concerning the survivability issues of the usersP2P network under a new information-sharing network environment. In this newinformation-sharing network, a local server proxy provides services to one or more userP2P networks. If the local proxy server fails, it affects all users within the coverage.There are also many other security problems in the user P2P network. Therefore, thispaper concentrates on how to improve service survivability of the user P2P network,under the condition of security risks within local proxy server and P2P network itself.This paper first introduces the content and significance of this research based onthe project background. Then we describe the related technical and theoreticalspecifications of network survivability. We then focus on the survivability technologyfor this new type of information-sharing network, for example: the service migrationtechnology， the trust mechanism in P2P network, and the connectivity relatedknowledge of the connectivity of nodes.Then, a new scheme of service migration based on super node is proposed focusingon the fault and intrusion tolerance of P2P network. While the general scheme is toachieve the migration among a group of servers, this scheme achieves the migrationbetween a local proxy server and a group of super nodes with a better performance. Thebasic services migrate from the proxy server to a group of super nodes in order toprevent the proxy server failure. Thus, it can guarantee the availability of basic servicesin the network, and improve the survivability of network service. Since the super nodesare selected form the user network, it is very important to identify them from the numerous other user nodes for the implementation of the migration scheme. Theperformance of the super nodes also directly influences the performance of themigration scheme. Therefore, this article focuses on the super node selection algorithmin the migration scheme, and proposed one based on the credible connectivity index ofthe user P2P node. When determining the super nodes，we need to consider the networkconnectivity problem in order to adapt to the dynamic changes of the network. This alsoimproves the ability of the user P2P node against with the churn of P2P network. Inorder to contain those nodes with malicious behavior, the reliability of nodes also needto be considered.Finally, we analyze the performance of the super node selection algorithm based onOPNET modeler14.5. The results show that this algorithm not only reduces networkcollapse probability when the topology of the network changes dramatically, but alsocurbs the malicious nodes in the network effectively.