Source-location privacy for networks of energy-constrained sensors

Wireless sensor networks are currently being investigated for ubiquitous computing applications. Privacy is a critical issue for these networks as adversaries may be able to eavesdrop or observe the presence of sensor data to infer information that was not intended to be revealed. The devices that constitute sensor networks are low-powered, compute-constrained devices. Any privacy solution should carefully consider the tradeoffs between supporting location-privacy and energy consumption. We explore two main classes of privacy issues: content privacy and originator location privacy. Content privacy can be maintained through conventional cryptographic methods that provide data confidentiality. We briefly discuss system design techniques that are needed to prevent an adversary from correlating observations from multiple messages to infer the content of encrypted sensor readings. We then examine the issue of protecting the originating sensor's location by studying several multi-hop routing mechanisms for ad hoc networks. We focus our discussion on three classes of routing protocols: the class of the shortest path routing protocols, the class of flooding protocols, and a hybrid class of routing.