Secure Efficient Geocast Protocol for Sensor Networks with Malicious Nodes

Geocast sends packets to all sensor nodes within a specified geographical region in order to gather data from sensor nodes in that region and is an important mechanism in sensor networks. In this paper we first introduce a new geocast protocol. The proposed protocol builds a multicast tree connecting geocast nodes using an energy efficient broadcasting technique without making any restrictions on the shape of the geocast region. The proposed protocol reduces the energy consumption during the phase of sending commands to the sensor nodes in a geocast region and also facilitates in-network data aggregation and, therefore, saves energy during the phase of reporting sensor data. Then we modify the proposed protocol to include security mechanisms to protect the multicast tree and data being transferred over this tree not only from outside attackers but also compromised insider attackers.