Security Architecture, Trust Management Model with Risk Evaluation and Node Selection Algorithm for WSN

Abstract

Wireless sensor networks are ideal candidates to monitor the environment in a variety of applications such as military surveillance, forest fire monitoring, etc. In such a network, a large number of sensor nodes are deployed over a vast terrain to detect events of interest (e.g., enemy vehicles, forest fires), and deliver data reports over multihop wireless paths to the user. Security is essential for these mission-critical applications to work in an adverse or hostile environment. Wireless Sensor networks are typically characterized by limited power supplies, low bandwidth, small memory sizes and limited energy. This leads to a very demanding environment to provide security. Public-key cryptography is too expensive to be usable, and even fast symmetric-key ciphers must be used sparingly. Communication bandwidth is extremely dear: each bit transmitted consumes about as much power as executing 800–1000 instructions(J. Hill et al 2000), and as a consequence, any message expansion caused by security mechanisms comes at significant cost. Wireless sensor networks consist of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations. In addition to one or more sensor nodes, each node in wireless sensor networks is typically equipped with a radio transceiver or other wireless communication devices, a microcontroller, and an energy source, usually a battery. Wireless sensor networks are the connection between physical world and mankind, which cannot be simply regarded as communication networks. It should mainly concentrate on sensory information processing and services. Wireless sensor networks should be developed as an integrated information infrastructure, in which information aggregation and collaborative processing are key issues. 19