Research On Key Management Based On The Reputation Mechanism In Wireless Sensor Networks

Wireless sensor networks is constituted by a large number of sensor nodes with computing and communication capabilities, can perceive and collect the information of the various objects or monitor the objects real-time in the network distribution area..Due to its closely linked to the physical world and without pre-deployed infrastructure, it has a wide range of applications in the areas, such as vehicle traffic control, target tracking, battlefield environment and disaster relief. Wireless channel is open and sensor nodes are often deployed in unattended harsh environment, making WSNs security threats not only from external attacks, as well as internal node attack. In order to solve the security problem in WSNs, a set of security policies must be adopted. Key management protocol is the basis of other security mechanisms. In addition, most of the mechanisms assume that all nodes in the network itself is credible, however nodes in the network may be captured which provide wrong services. Due to computing power, storage communication bandwidth and battery energy are severely limited, the nodes prone to failure. These new security problems encountered in WSNs can not be solved relying solely on traditional cryptography, and therefore nodes credibility is introduced into the key management in tis paper.In order to solve the issue of credibility and security in WSNs, a reputation management model based on the node behavior in WSNs has been designed by drawing on draw on the experience of credibility/trust. The model formally use beta distribution to describe the expression and update of sensor nodes’ directly credibility, and calculate the trust value.It also introduce the confidence to measure the credibility of the trust value, given the acquisition and processing of indirect credibility. The direct trust is integrated with indirect trust by using the methods of Statistics and the overall trust value of the node is calculated.A key management scheme based on the node reputation mechanism and elliptic curve cryptography has been presented which combined with the key characteristics and the needs of WSNs. The keys’ distribution, update, revocation, as well as the key generation about new node have been implemented in the scheme. The scheme uses a fully distributed architecture, each node deployment parameters according to the result of the interaction of neighbors, and according to the requirements recommend the parameters to others.The master node computes the reputation values according to the direct trust value and the other peer’s recommendation trust value under the model, then determines whether the value is less than a predetermined threshold value. If it is true, the node will be break or hang the key which has been generated, otherwise, will realize key negotiation and updated.The simulation and analysis have been done base on the the node acts of reputation management model and key management scheme based on the credibility of the model. The experiments show that the proposed scheme is able to effectively identify malicious nodes and failure node, then exclude the malicious nodes outside the network.Ensuring the key connectivity effectively reduces the storage space of the key and in the key update phase join confidentiality and authentication function, the scheme increasing the network security, reliability and the difficulty of attacks.As the key management is self-organizing style, the network has good expandability.