Securing group communication in wireless sensor networks

In this paper, we present a secure group communication protocol for multi-hop, wireless sensor networks. Our protocol which is based on hierarchical tree works well on bidirectional communications between the base stations and sensor nodes. Tree construction is initiated by the base station which broadcasts solicit packet to discover child nodes. Sensor node receiving this packet decides an appropriate parent to which it attaches, it then broadcasts solicit packet to discover child nodes in the next level of the tree. This process is performed on every node. Consequently, hierarchical tree is rapidly created without flooding of any routing information packets. Based on a combination of symmetric key encryption and public-key encryption algorithm, both base stations and sensor nodes can securely discover route and confidentially communicate and authenticate communicating parties. We also propose a method to manage tree and keys when members join or leave from the group to achieve robustness of the protocol.