earticle

영어

Many sensor network security schemes protect the content of messages, while the contextual information is left vulnerable by disclosing the location of the monitored objects. Preserving location privacy is important and one of the most challenging issues in many mission critical sensor network applications. Prior solutions are mostly designed to protect privacy from local attackers who eavesdrop on traffic in a small region at a time. However, they can be easily defeated by highly motivated global attackers that can trace the entire network’s communication events. Although a few recent privacy solutions are proposed against global attackers, they suffer from significant communication overhead as they inject dummy traffic or send messages in a globally synchronized manner. As a result, they consume a lot of energy to maintain a desired privacy level that makes the network lifetime shorter. We propose an energy-efficient source location privacy preserving solution, named the Energy Efficient Location Privacy Scheme against global attackers (E-LPG). E-LPG hides original source locations through a spatial scatter of messages using stealthy wormholes and through a temporal scatter using random delays when permitted. With a limited number of wormholes, E-LPG can achieve a high privacy level without incurring extra communication overhead. We evaluated the efficiency and effectiveness of E-LPG through theoretical analysis and extensive simulations. We have shown that E-LPG also produces dramatic synergistic results when used with other privacy schemes complementarily.