Improved group-key-management scheme for WSN

Deployment of wireless sensor nodes as a result of extensive, easily captured by the enemy, resulting in the leakage of key. In order to ensure the secure communications of wireless sensor networks, this paper advances a scheme, which repuires each node update the original key at given intervals, and discards the original key. In this way, even if the enemy captures the sensor nodes, they could only get some old keys, so it can´t pose a threat to the network, This will ensure the security of network communications. And in order to reduce the communication overhead, we also adopted the method that the cluster head nodes come from ordinary nodes.