Research On Group Key Management Mechanism For Wireless Sensor Networks

Sensor network is composed of lots of sensor nodes, which work together for acquiring, processing information. Meanwhile, sensor network is resource-limited. Such limitations include computation ability, memory capability, power limitation and communication bandwidth and range. Many emerging wireless applications for emergency and military situations depend upon secure group communications. But group key management in sensor networks faces a great challenge because of the resource-limited. This paper mainly focuses on the group key management in sensor networks.This paper firstly introduces wireless sensor networks and its security issues, and then introduces the problems need to be solved and some difficulties in group key management scheme in wireless sensor networks. In according to the characteristics and security requirements of sensor networks, by using several evaluations analyzes and compares some group key management schemes in sensor networks.In order to decreasing the network overheads, this paper presents a lay-cluster group key management scheme based on the logic key tree and threshold secret sharing mechanism. In the scheme, the lay-cluster structure based on the logic key tree effectively disperses the memory and computational capacitance, which avoids the storage and computation bottleneck problems of the group control node in centralized group key management, but also overcomes the deficiencies lack of centralized control in distributed group key management. But in the same layer the acquisition of new group key uses key negotiation algorithm, spending more calculation. And sending group key by the key tree, its broadcasting capacity, memory and communication overheads remain high. At the same time, when the number of node neighbors failed or captured, the nodes group re-keying will be seriously affected and could not even update become to isolated nodes. To solve the shortcomings in the lay-cluster scheme, based on LEACH protocol in sensor networks, this paper presents an improved lay-cluster group key management scheme. Compared to the above scheme, when group re-keying, the new group key is only generated by cluster head and will be distributed to the nodes in cluster securely. In order to realize the secure group key distribution, the improved scheme using layer key generation algorithm to achieve secure communications between cluster and the nodes in cluster. Theoretical analysis and simulation results show that the improved scheme has the same security with the distributed scheme, decreases the computer and communication overheads and solves the isolated node problem in distributed scheme.