  Wireless sensor networks (WSNs) have recently attracted a lot of interest in
the research community due their wide range of applications. Unfortunately,
these networks are vulnerable to numerous security threats that can adversely
affect their proper functioning. This problem is more critical if the network
is deployed for some mission-critical applications such as in a tactical
battlefield. Random failure of nodes and intentional compromise of nodes by an
insider attack in a WSN pose particularly difficult challenges to security
engineers as these attacks cannot be defended by traditional cryptography-based
mechanisms. In this paper, a security solution is proposed for detecting
compromised and faulty nodes in a WSN. The mechanism also isolates a
compromised node from the network so that it cannot participate in any network
activity. The proposed mechanism is based on misbehavior classification,
behaviour monitoring and trust management. It involves minimum computation and
communication overhead and is ideally suited for a resource-constrained,
high-integrity WSN.
