Research On Trust Model In Mobile Ad Hoc Networks

Mobile Ad Hoc networks (MANET) are new paradigm of wireless networks, which can be quickly put up to provide mobile communication without any underlying infrastructure anytime and anywhere. However, wireless MANET is particularly vulnerable due to its fundamental characteristics, such as open medium, dynamic topology, distributed cooperation, and constrained capability. Security is essential for MANET, and it is also one of the hot areas in MANET research nowadays. Because that the establishment of trust relation is the basis to implement all the security policies, this dissertation focus on the trust model for Mobile Ad Hoc networks.The foundational conception, features, security requirements and security threats of MANET are introduced. Thorough research of the trust models for Mobile Ad Hoc Networks. Finding that there are many problems that can not be solved through traditional security policies: such as the establishment and revocation of identity trust relationship lack of decision standard; In behavior trust model it is not ensure of identity trust at large.In order to solve these problems, A trust model based on PKI of hierarchy MANET is introduced. It has characteristic as follows:(1)This dissertation integrates identity trust and the trust evaluation mechanism: the establishment of identity trust relationship, it boosts security and creditability of the trust evaluation mechanism; contrarily, creditability of the trust evaluation mechanism provide decision-making gist for updating and revocation of identity trust relationship, and for boosting up security and dependability of authentication process more.(2)CA function of PKI system is disparted two parts, nodes digital certificate making and maintenance. Nodes enter into network gaining digital certificate non-line. It not only mitigate burden of MANET, but advance security of CA; updating and revocation of digital certificate are completed in Ad Hoc network.Contraposing various frequencies hiberarchy of MANET, the trust model takes mix mode of integrating muster mode and distributing mode, The model introduce share a secret in cluster-headers, certificate updating system secret key are distributed storage, enhancing the security of system; Cluster-headers is responsible to the security and routing, actualizing effective control to security of cluster member, enhancing the usability of the security service.(3) Thesis improves arithmetic of evaluation and maintenance for digital certificates trust identity, the security and reliability of MANET can be adjusted by revocation coefficient, the effect of hostility node can be debased by comeback coefficient, these can be control the incertitude complication of the trustevaluation mechanism availably.Finally, this dissertation analyzes and evaluates the security of the improved trust model.