Enhancing Source-Location Privacy in Sensor Network Routing

Abstract

Abstract-One of the most notable challenges threatening the successful deployment of sensor systems is privacy. Although many privacy-related issues can be addressed by security mechanisms, one sensor network privacy issue that cannot be adequately addressed by network security is source-location privacy. Adversaries may use RF localization techniques to perform hop-by-hop traceback to the source sensor's location. This paper provides a formal model for the source-location privacy problem in sensor networks and examines the privacy characteristics of different sensor routing protocols. We examine two popular classes of routing protocols: the class of flooding protocols, and the class of routing protocols involving only a single path from the source to the sink. While investigating the privacy performance of routing protocols, we considered the tradeoffs between location-privacy and energy consumption. We found that most of the current protocols cannot provide efficient source-location privacy while maintaining desirable system performance. In order to provide efficient and private sensor communications, we devised new techniques to enhance source-location privacy that augment these routing protocols. One of our strategies, a technique we have called phantom routing, has proven flexible and capable of protecting the source's location, while not incurring a noticeable increase in energy overhead. Further, we examined the effect of source mobility on location privacy. We showed that, even with the natural privacy amplification resulting from source mobility, our phantom routing techniques yield improved source-location privacy relative to other routing methods.

On the Use of Fake Sources for Source Location Privacy: Trade-Offs Between Energy and Privacy

“…The problem of source location privacy first appeared around 2004 [7] [15]. Since then, the problem has been addressed using a variety of attacker models and assumptions.…”

“…In another work, Kamath et al [8] presented an approach that used triangulation to locate targets. In contrast, in a seminal paper on source location privacy, Kamat et al [7] assume a single attacker, who can use the adopted routing protocol to infer the location of a source node. For example, in a military environment, soldiers on surveillance may relay information to a sink.…”

“…Several techniques to handle the source location privacy problem have been proposed, e.g., [7] [13] [1] [10] [20]. In this paper, we focus on the fake source technique.…”

“…If the location(s) of the source node(s) is compromised, then an attacker can capture the asset. In the seminal work on source location privacy, the asset being monitored was taken to be a panda, which is an endangered animal [7].…”

“…However, current algorithms that are based on the fake source technique are of limited relevance, since they make a number of assumptions which limit their practicality. For example, (i) fake sources are often known a priori or arbitrarily chosen [13], (ii) fake sources are selected based on a prohibitively expensive pre-configuration phase or the need to have network-wide knowledge [7], (iii) no common attacker model is adopted, making it is difficult to understand the efficiency of proposed algorithms [7] [13] [10], and (iv) there is a lack of results demonstrating the level of privacy that can be afforded by the fake source technique.…”