Securing Wireless Sensor Networks Using Cluster Reformations

In sensor networks, sensors are prone to be compromised by attackers because they are deployed in an unattended environment. Then, attackers can employ the keys of the compromised sensors to uncover the sensor readings and even modify them to lead an unsuitable decision of the user. To resolve the problem, it is important to refresh communication keys of sensors in a periodic or on-demand manner. In this paper, we propose a key refreshment scheme which is immune to the increase of the compromised nodes. In our scheme, each member in a cluster uses a pairwise key which is different from those of other members, so the compromise of a sensor reveals no transmissions from other members. Besides, our scheme explicitly evicts the compromised sensors by virtue of periodic cluster reformations. Simulation results showed that our scheme is more tolerant to the compromised sensors while it is more energy-efficient than SHELL.