Protecting Sensor Networks using Risk Analysis

Nodes in a sensor network possess minimal computational, storage and communications resources as well as limited energy supplies. Consequently implementing security mechanisms such as encryption is expensive in such networks. Typically a node will employ security mechanisms at all times. If a node can invoke defense mechanisms only when it is under threat from a malicious attacker, resources can be conserved. In this work we use a mixed strategy game to model attackers and defenders in a sensor network. The game is based on the risk level among other parameters. Since risk is difficult to quantify, we use a fuzzy logic model for risk assessment. The proposed game model suggests that there are times when defending is not worth the cost.