Research On Key Management Schemes And Clustering In Wireless Sensor Networks

WSN(Wireless Sensor Network) is a self-organized network with multiple hops composed by numerous, small, low-cost sensors using wireless communication. Due to its characters, WSN is widely used in many areas such as military, medical application, smart home and so on.Usually, sensors are deployed where people can not arrive, and in many applications security is an important problem. For example, in a military application, a deployed sensor may be captured by the enemy, so wireless sensor network should have anti-attack ability to prevent disclosure of sensitive information.In traditional security mechanisms, encryption and authenticity are two important aspects while key management is the basis of them. Recently, many key management schemes for WSN are supposed in which pre-distribution schemes are suitable for WSN character. But few of the proposed schemes mention revocation of the key while the sensors are captured.The final request of the WSN is to collect information and transform it to the base station. To improve the efficiency and to save energy, hierarchical model of WSN is a central issue. There is no mature key management scheme for hierarchical WSN.In response of these problems, we propose one self-healing key management scheme with revocation in hierarchical WSN. Considering the characters of WSN, we aim at saving the cost of communication, computation and storage to make the design practical. On the other hand, while the current clustering algorithm does not consider the energy effect, we propose an improved clustering algorithm over our key management architecture.The main work of this paper include:1) Summarize current key management schemes in wireless sensor network and list there advantages and disadvantage to find a reasonable research point2) A key management scheme in hierarchical wireless sensor network is proposed. We divided the network period into many session slots as the LEACH scheme. In each session cycle, only one broadcast by the base can complete the authenticity work and key revocation of the malicious nodes. In this way, we verify the identity of the cluster head and remove the malicious node from the network to prevent hello flood attack. Though adding many security schemes, our proposal does not increase the cost of the network because most of the application are based on the broadcast of the base station. The experiments show that our scheme does not cause additional cost based on the LEACH protocol.3) Our proposal is based on hierarchical wireless sensor network but the LEACH does not consider the energy factor. To meet the need of our key management scheme, we propose one clustering algorithm in which we take the energy into consideration while data aggregation and use message piggyback technology to reduce the cost of control package transmission. The network lifetime is extended by using better selecting algorithm. The experiments show that our proposal can save energy in the node and extend the network lifetime.