Research On Key Management For Wireless Sensor Networks

Wireless sensor networks (WSNs) are bringing about a revolution in the means of information perception and information acquisition. It changes the interactive mode between human and nature. WSNs are prone to all kinds of attacks thus security becomes the first concern. As a foundational security service, the key management plays an important role in the security of WSNs.This thesis focuses on the key management problems, and presents some positive research achievements. Firstly, a hexagon-based key predistribution scheme was presented. It uses hexagon-based model to partition the deployment area, construct the key pool, distribute the keys and deploy the sensor nodes. This scheme increases the probability of pair-wise key establishment and improves the connectivity of WSNs. Secondly, a key management scheme for heterogeneous wireless sensor network using keyed-hash chain is presented. It uses keyed-hash chain with the strategy of decentralized secret storage, so as to a compromised node will not discolse the secure links of the other nodes, and at the same time, which can avoid that the network goes into paralysis for cluster head becomes invalid. The high-powered cluster heads and base station make up of the two levels KDC, which can improve the connectivity to 1 by online key distribution. Correlation analysis results show that compared with the former works, this scheme greatly improves the resilience and key connectivity of WSNs, and lowers the storage costs. At last, a sliding-window self-healing key distribution mechanism is presented for self-healing group key distribution mechanism based on dual direction hash chain is usually vulnerable to collusive attack from its adversaries. It uses keyed-hash function to form dual directional hash chain. The self-healing key takes part in the computing of the corresponding session key. By using a sliding-window, the self-healing interval is limited to a certain range, which reduces the exposure of keys and achieves the capability of resisting collusion attack from the nodes lying outside the self-healing interval. Correlation analysis and simulation results show that compared with the former works, the key distribution mechanism greatly lowers the risk of collusion attack and effectively improves security under the same efficiency level.