Efficient Multi-Level Key Update Scheme Based on Cluster and Random Key Pre-Distribution

The problem of key update in sensor network is its slow update,wide range update and energy consumption.In response to these issues,a method of two level key renewal theories is proposed.By update methods,a unicast mode is used between base station and cluster head.The update is unique and different for each cluster head while the polynomial broadcast mode is used between cluster heads and normal nodes.The new method is drawn from slot authentication,it generates the session key by storing key,and has no additional storage overhead.Besides,this method reduces polynomial orders and computation amount of nodes,updates the exposed key quickly,ensures unchanged of key pool size,guarantees the good connectivity of network,and extends the network lifetime at the same time as well.Simulation shows that this method improves the key update speed,and the energy consumption becomes bearable.