Key Management Schemes For Wireless Sensor Networks Based On Key Pool

With the development and progress of microelectronics technology, computing andwireless communication technology, wireless sensor networks (WSNs) are widely used inmilitary, environmental observation, forecast system, medical care and other fields. However，due to the resource constraints and the complexity of working environment, WSNs face nodecapture, selective forwarding and other security threat which cause leakage of privacy data.So security technology of WSNs should be first solved for the large scale application.In recent years, domestic and foreign scholars present many more practical and effectivekey management algorithms for WSNs. The schemes which are based on symmetriccryptosystem have many advantages compared with other algorithms, and are more suitablefor resources severely limited WSNs. However, these studies still exist many problems, suchas the algorithm is too complex, the connectivity has contradiction with the resistance againstnode capture attack, the security of network degrades with time and so on.Therefore, with the motivation of improving the security and connectivity of network,this article will try to explore new key management schemes for WSNs. The maincontributions are as follows:1) Group and deployment knowledge based key management for WSNs is proposed.First, deployment area is divided into several non-overlapping hexagonal grids and nodesare separated into groups, each of which is deployed in the corresponding grid, and thenthe multiple key space algorithm based on Blom is applied to each group and basic clusterwhich contains three adjacent grids. In the proposed, the blindness of key distribution isreduced by using deployment knowledge, which makes it possible for the neighboring nodesto have common keys with larger probability, and meanwhile, the influence of node captureattack on the performance of the network security is restricted through the safety threshold ofBlom algorithm. Theoretical analysis and simulation experiments show that this scheme caneffectively improve the network connectivity and the resilience against node captureattack.2) Hash Chain based key management for multi-phase WSNs is presented. Assumingthat the lifetime of sensor node is less than the whole network, the lifetime of network ismodeled using the concept of deployment period. In the scheme, each node utilizes keyswhich are selected randomly from forward key pool and backward key pool to ensure theforward security and backward security of network, what’s more, through updating the key pools in each new generation, the lifetime of keys is limited, which reduces the opportunityfor attacker to use the captured keys to implement further attacks. Theoretical analysis andsimulation experiments show that the proposed scheme can guarantee the performance againstnode capture attack of network doesn’t deteriorate over time while involving in loweraverage insecure degree.