Toward Delay Tolerant Network Anonymity: Threshold Pivot Scheme

Research on Delay and Disruption Tolerant Networks (DTNs) challenges the traditional assumption of end-toend connectivity, extending networked communication to e.g. intermittently connected devices, ad-hoc mobile environments, first-responder disaster scenarios, etc. In such environments, ensuring the security and privacy of both content, networks, and participants is often vital. In this work, we consider DTN anonymity and privacy. The disconnected nature of DTNs presents a unique difficulty for traditional anonymity approaches, namely limited knowledge of other nodes and paths in the dynamic, mobile network. We develop a particular solution, the Threshold Pivot Scheme (TPS), to provide source anonymity and sender-receiver unlinkability in DTNs. Our scheme, based on secret sharing primitives, permits a user-selectable level of anonymity, an important feature for DTN environments that must balance security and usability. Through simulation and analytical analysis, we evaluate the performance and overhead of TPS and find that it addresses the constraints of DTNs while providing a suitably high-level of anonymity.