Abstract: Key management is crucially important for all security goals in WSNs.For solving the security vulnerabilities and heavy overhead problems of the existing key managements in heterogeneous WSN,a key management mechanism was put forward.The mechanism includes an ECC-based lightweight sigcryption algorithm which can not only cost less computation and communication,but also have better forward security.An entire cluster key management protocol is designed based on the above sigcryption that can ensure the communication security in the cluster and use cluster base key to generate the cluster key in each cluster.The employment of cluster base key can effectively avoid all SNs being invalid when CH is captured.To adapt the dynamic and scalability characteristic of WSN,the cluster key can be effectively refreshed and maintained by utilizing the cluster key refresh chain.In addition,a cluster key security management model was proposed which can self-adaptively refresh the cluster key according to the change of network environment thread and further improve the cluster key refreshment performance.The contrast results show that the presented mechanism is better than other existing mechanisms in terms of security and protocol performance.

Key words: Key management,Heterogeneous WSN,Elliptical curve cryptography,Signcryption,Cluster key