Wireless Sensor Network Security Mechanisms Based On Trust

The issue of security is an important issue for any networks, specially, it is more important for Wireless sensor networks (WSNs) which is a type of resource-contained network and typically has little or no infrastructure. The research about security of wireless sensor networks has been a hot research issue in WSNs.Because of the special characteristics that distinguish WSNs from other networks such as the MANETs and P2P make WSNs vulnerable to threats and risk. These threats and risks are novel; they are different from those conventional problems in the traditional wireless networks, so they are generally referred as"insider attacks". Although, many security protocols have been proposed to enhance the security of WSNs, but most of them focus on the authentication and encryption. Although, these methods have addressed many conventional attacks problems in the wireless networks, these attacks usually referred as"outsider attack", but many novel malicious attacks encountered in WSNs could not be entirely solved only by methods based on authentication and encryption. These methods could not protect WSNs against those"insider attacks"launched by those malicious nodes, compromised nodes or aged node, due to that adversarial node can have access to valid cryptographic keys to access other nodes in the network.Trust based security mechanism plays an important role in protecting WSNs against"insider attacks". Nowadays, the research of security mechanism based on reputation and Trust has become a hot research issue in wireless networks. This is a challenging area of research. But up to now, this research is still in an early state. A lot of effort has been done in trust management systems for P2P or MANETs. However, these systems do not fit all the requirements and features required by WSNs. With the development of WSNs, the Reputation and Trust based research for WSNs have gained worldwide attention in recent years.In this paper, we propose a new security protocol (resilient application Reputation Framework based Trust Model) to construct Trustworthy sensor networks through analyzing those pros & cons of existing security protocols based on Trust and Reputation. In our scheme, addition to sensor nodes, we randomly deploy agent nodes to monitor the actions of sensor nodes in WSNs to collect reputation information in relation to sensor node and compute the trust metric according to the type of application. This protocol not only can distinguish different task requirements, but also can rank Trust values and form ranking tables. At each requirement of application, sensor node will choose sensor nodes of candidate table to provide service. Further, the computing model of trust and the trust rank of sensors are based on the confidence degree of statistical result in order to achieve better reliability of computation of trust value. The objective of this protocol is not only to encourage nodes to provide good services consecutively to establish a security environment of network, but also to punish strictly those malicious nodes that are trying to take advantage of reputation system to launch malicious attacks.In summary, the main contributions of our work are as follows:1) Propose a novel local-central distributed scheme to achieve more reliable reputation information collection and calculation of trust value.2) Propose a scheme of calculation of trust value based on the type of task requirement; this scheme can reflect the performance of node.3) Develop a confidence degree based trust rating mechanism for establishing reputation between nodes to get more creditable trust value. 4) Propose an updating scheme of reputation based on transaction.5) Offer an algorithm of selection of reliable node to achieve better security performance.Finally, we simulate our designed scheme, and comparing it with some existing security scheme. Through intensive simulation, we have verified the correctness and efficiency of the proposed defense techniques. Simulation experiments show that our scheme is more efficient in defense against on-off attack and selective behavior attack, etc. Our scheme is more suitable for large scale WSNs to construct trustworthy WSNs.