On securing perimeter coverage in wireless sensor networks

The coverage problem in which a set of sensors is required to collaborate so as to preserve the whole perimeter of a big object is known as the perimeter coverage problem. With the assumption that two sensors are neighbors and connected if they have overlapping cover ranges, we have developed distributed algorithms to find the set of sensors to cover the entire perimeter with the minimum size and the minimum cost previously. Unfortunately, this assumption is invalid when some security measures, such as a secret key management scheme, are applied to the sensors. In this paper, we are specifically interested in finding a set of sensors to monitor the target object with the minimum size and the minimum cost. At the same time, the sensors inside the set can communicate with its secure neighbors such that a secure communication path can be formed from any sensor inside the set to another sensor inside the same set. We first demonstrate why our previously proposed algorithms fail under this situation and further propose a modified model and algorithm so that the minimum size and minimum cost sets of sensors can be found. Finally, we simulate our proposed algorithm to demonstrate its effectiveness.