Research On Key Management Scheme For Wireless Sensor Networks

Wireless sensor network (WSN), which integrates the technologies of sensor, micro-electro-mechanism system, wireless communication and distributed computing, is a next generation of network. Its applications have extended over environment monitoring, traffic management, heath and medical community and so on. Security about wireless sensor network is a very challenging at integrated effect of many factors, such as intricate secure environment, various secure requirement and 1imited resources. As a fundamental requirement for providing security in wireless sensor network, key management plays an essential role in authentication and encryption. In this paper, we focus on the key issues of key management to design secure and efficient key management schemes for wireless sensor network. The main contributions are outlined as follows:(1) Considering the limitation of power, computation and storage resources of wireless sensor networks, a new random key pre-distribution scheme using deployment knowledge is proposed. In the scheme, the sensor nodes will be deployed according to a hexagonal structure or a square structure, and then the good coverage efficiency can be obtained. Nodes only need to preload a few of secret keys, and then can establish shared keys with a very high probability. Wireless sensor networks can maintain a good connectivity even though there are a lot of mobile nodes. Theoretic studies and figures of simulation show that the proposed scheme provides better performance in connectivity and in the number keys than some classical schemes.(2) For the application of sensor nodes mobility, a key management scheme for heterogeneous sensor networks is proposed based on elliptic curve cryptography. The nodes of the same cluster can directly establish pairwise key, and that the nodes of the different clusters can establish path key through the base station or cluster head. Theoretic studies show that the validity of key can be authenticated, so a number of attacks including masquerade, reply and message manipulation attacks can be resisted. The new scheme can not only increase the security, but also decrease the nodes storage cost.(3) To implement the authentication mechanism in wireless sensor networks, the identity of node can be authenticated using bilinear pairing cryptography over an elliptic curve, and the attacks of the illegal nodes can be resisted by verifying the legitimacy of the nodes. A dynamic trust model without any third-party certification server is proposed. In the dynamic trust model, by mutual authenticating, the neighbor nodes can set up shared key, routing information to base station, and construct a dependable network.(4) Using elliptic curve cryptography, a unilateral routing key management scheme for wireless sensor networks is proposed. In the scheme, when there have communication between the nodes, the nodes set up shared secret keys. In the process of key request, the validity of the node and routing can be verified by the digital signature between the nodes in the scheme, while in the process of key reply, the middle nodes do not need such verification. Analysis results show that the new scheme resists a number of attacks such as forgery attack, tamper attack and so on. In the efficiency of key establishment, the new scheme more effective than those schemes which the middle nodes must do such verification in the process of key reply.