Research On Key Management Schemes For Multiphase Wireless Sensor Networks

Wireless sensor networks(WSN) need to face all kinds of security threats, for example, nodes that exposed in unsafe environment are easyly to be captured; with radio signal is easyly to be intercepted, etc. So the security problem is an important research direction in wireless sensor networks. In this thesis, the key management aspect is deeply studied and a new random key pre-distribution scheme based on HaXOR function in multiphase WSN and cellular model is proposed.This thesis focuses on studying and analyzing random key distribution scheme and key distribution scheme using deployment of knowledge. Because random key distribution scheme spends less storage space in the node, has a better network scalability, supports for large-scale network, limits the influenced sphere of captured nodes, has higher network security, it is an important research direction of the current key management issues. Key pre-distribution scheme using deployment knowledge divides the deployment region into several groups, at the same time it divides the key pool into several groups. By this means the connectivity of the neighbor nodes can increase, thus greatly improving the security of the entire network connectivity. Due to these advantages, the key pre-distribution scheme using deployment of knowledge becomes an emerging key management technology.On the basis of E-G scheme and based on multiphase WSN, combining with hash function and xor operator, this thesis proposes a new scheme named H-X scheme. In this scheme, deploying new nodes to the environment in certain generations, each deployment generation has its own key pool and these pools are generated using the pool of the previous generation which two sequential keys are XORed and hashed together, when the generation period ends, nodes should immediately delete the keys from the past generation key pool. When two nodes need to communicate with each other, the communicated key must established in generation interval. After that analyzes the partition model, improves the regular hexagon partition model, divedes the deployment region into core area and secondary area. The corresponding sub-key pool of the core area is assigned the key by the base station key pool directly, the corresponding sub-key pool of the secondary area is assigned the key by the corresponding sub-key pool of the core area arrounding the secondary area. This scheme can simplify the complexity of dividing sub-key pool, increase the connetivity of the adjacent deployment area.