Sense-And-Trace: A Privacy Preserving Distributed Geolocation Tracking System

The capabilities of modern smartphones pave the way for a new collaborative usage of this technology. Several researchers already envisaged to use this technology for distributed sensing purposes. In par- ticular, one of these purposes focuses on tracing devices (people) move- ment. Current solutions for distributed tracing (either based on infor- mation provided by the mobile nodes, or collected by the surrounding network) have some limitations: e.g. accuracy, privacy, cost of deploy- ment, and cost of operation. The aim of this paper is to highlight the open problems of distributed geolocation tracing and to propose a solution for some of the current problems. In particular, we propose Sense-And-Track (SAT), which is a system that makes use of collaborative sensing to collect information about other mobile nodes with the final aim of tracking potential target nodes. In SAT, information is collected in a way such that the privacy of nodes that voluntarily collaborate is preserved, and the information of the mobility of a node is disclosed only to the authorized entity (e.g. a law enforcement agency with the appropriate permission). Our solution can be seen as an enhancement of the classical “neighborhood watching” concept, with fine-grained mobility information automatically-collected through the devices carried by humans.