Differentiated Coverage Based Key Management Scheme for Heterogeneous Sensor Networks

previous research on sensor network security mainly considers homogeneous sensor networks, where all sensor nodes have the same capabilities. Research has shown that homogeneous ad hoc networks have poor performance and scalability. The many-to-one traffic pattern dominates in sensor networks, and hence a sensor may only communicate with a small portion of its neighbors. Key management is a fundamental security operation. Most existing key management schemes try to establish shared keys for all pairs of neighbor sensors, no matter whether these nodes communicate with each other or not, and this causes large overhead. In this paper, we adopt a heterogeneous sensor network model to overcome these problems. Sensing coverage is a fundamental problem in sensor networks and has been well studied over the past years. However, most coverage algorithms only consider the uniform coverage problem, that is, all the areas have the same coverage degree requirement. In many scenarios, some key areas need high coverage degree while other areas only need low coverage degree. We propose a differentiated coverage algorithm which can provide different coverage degrees for different areas. The algorithm is energy efficient since it only keeps minimum number of sensors to work