Research On Key-Management For Wireless Sensor Networks Based On Clustering

Recent advances in sensor,wireless communication and data processing have enabled the development of wireless sensor networks(WSNs). Wireless sensor network is a new technology about acquiring and processing information. In wireless sensor networks, lots of sensor nodes work cooperatively to apperceive, acquire and process information from sensor fields, and transfer it to observers, with wireless communication and self-organization.Wireless sensor networks can be used for various applications, such as military fields, environment research and outer -space exploration.Because of opening of deployment area and broadcasting of wireless networks ,WSN is prone to be traffic-listened and be up against other different types of malicious attacks, security becomes extremely important. To provide secure communications,messages should be encrypted and authenticated. Robust and efficient key management scheme is the solution of network security, so the key distribution and management become the key point. Sensor nodes are highly resource constrained, typically low energy and battery powered; they are deployed in inaccessible environment, limited in memory ,computional capabilities and only have short-range radio communications.So some key management schemes used in traditional networks are not fit WSNs.It needs to put forward new methods for key distribution and management.This thesis briefly introduces the conceptions and corresponding contents of sensor networks , proposes a new key management scheme based on clustering(KMBC) for wireless sensor network security, then analyses improvement of network security, connectivity,extension, resistance to some malicious attacks and power-efficiency.Key-distribution is the important and difficult point in the scheme.A key-distribution algorithm based on clustering is proposed. The base station distributes key-pools for every cluster according to the distance between a cluster to it using clustering information which is gained by routing protocol,then it sends key-pools to corresponding cluster-head, the cluster-head distributes key-rings for interior-cluster nodes and gateway nodes,which locate in area that two or several clusters overlap. Key-rings stored in a gateway node come from all clusters the node connects,so secure communication inter-cluster is practical. KMBC scheme adapts to WSNs that adopt cluster-based routing protocol. Security and connectivity is evidently improved in wireless sensor networks adopting KMBC. In addition,this scheme can sustain lage-scale netwoks and network dynamic transformation, and it has resistance to some malicious attacks aim to WSNs.