Christine Laurendeau

Centroid localization of uncooperative nodes in wireless networks using a relative span weighting method

Increasingly ubiquitous wireless technologies require novel localization techniques to pinpoint the position of an uncooperative node, whether the target is a malicious device engaging in a security exploit or a low-battery handset in the middle of a critical emergency. Such scenarios necessitate that a radio signal source be localized by other network nodes efficiently, using minimal information. We propose two new algorithms for estimating the position of an uncooperative transmitter, based on the received signal strength (RSS) of a single target message at a set of receivers whose coordinates are known. As an extension to the concept of centroid localization, our mechanisms weigh each receivers coordinates based on the messages relative RSS at that receiver, with respect to the span of RSS values over all receivers. The weights may decrease from the highest RSS receiver either linearly or exponentially. Our simulation results demonstrate that for all but the most sparsely populated wireless networks, our exponentially weighted mechanism localizes a target node within the regulations stipulated for emergency services location accuracy.

Insider attack attribution using signal strength‐based hyperbolic location estimation

A rogue insider, in a wireless network, is an authenticated member that exploits possession of a valid identity in order to launch an attack. A typical example is the transmission of a verifiable message containing false or incomplete information. An important step, in enabling the network authorities to attribute an attack message to its originator, involves locating the physical source of the transmission. We propose a probabilistic scheme to determine the location of a transmitting rogue, with a degree of confidence, using the relative signal strength received by neighboring devices, even if the effective isotropic radiated power (EIRP) employed by the rogue is unknown. The relative received signal strength (RSS) between pairs of trusted receivers are combined with a range of possible EIRP values to construct an area in Euclidian space bounded by minimum and maximum distance hyperbolas. The area contained within the intersection of multiple hyperbola pairs pinpoints the location of the rogue transmitter with a specific level of confidence. Copyright

Secure Anonymous Broadcasting in Vehicular Networks

Vehicular networks face a typical quandary in their requirement for communications that are at once secure and private. While the messages broadcast between vehicles and between vehicles and the supporting infrastructure must be authentic and non repudiable, they must also ensure the vehicle drivers anonymity. The Dedicated Short Range Communications (DSRC) frameworks Wireless Access in Vehicular Environments (WAVE) application development architecture mandates the use of Public Key Infrastructure (PKI) mechanisms for securing messages, consequently compromising the drivers expectation of privacy. In this paper, we propose a WAVE-based protocol for the secure and anonymous propagation of vehicle safety broadcast messages. A hybrid key infrastructure approach is put forth which combines the use of a shared network authorization key for devices that require anonymity and PKI for devices that do not.

Probabilistic localization and tracking of malicious insiders using hyperbolic position bounding in vehicular networks

A malicious insider in a wireless network may carry out a number of devastating attacks without fear of retribution, since the messages it broadcasts are authenticated with valid credentials such as a digital signature. In attributing an attack message to its perpetrator by localizing the signal source, we can make no presumptions regarding the type of radio equipment used by a malicious transmitter, including the transmitting power utilized to carry out an exploit. Hyperbolic position bounding (HPB) provides a mechanism to probabilistically estimate the candidate location of an attack messages originator using received signal strength (RSS) reports, without assuming knowledge of the transmitting power. We specialize the applicability of HPB into the realm of vehicular networks and provide alternate HPB algorithms to improve localization precision and computational efficiency. We extend HPB for tracking the consecutive locations of a mobile attacker. We evaluate the localization and tracking performance of HPB in a vehicular scenario featuring a variable number of receivers and a known navigational layout. We find that HPB can position a transmitting device within stipulated guidelines for emergency services localization accuracy.

Relative Span Weighted Localization of Uncooperative Nodes in Wireless Networks

Increasingly ubiquitous wireless technologies require novel localization techniques to pinpoint the position of an uncooperative node, whether the target be a malicious device engaging in a security exploit or a low-battery handset in the middle of a critical emergency. Such scenarios necessitate that a radio signal source be localized by other network nodes efficiently, using minimal information. We propose two new algorithms for estimating the position of an uncooperative transmitter, based on the received signal strength (RSS) of a single target message at a set of receivers whose coordinates are known. As an extension to the concept of centroid localization, our mechanisms weigh each receivers coordinates based on the messages relative RSS at that receiver, with respect to the span of RSS values over all receivers. The weights may decrease from the highest RSS receiver either linearly or exponentially. Our simulation results demonstrate that for all but the most sparsely populated wireless networks, our exponentially weighted mechanism localizes a target node within the regulations stipulated for emergency services location accuracy.

Hyperbolic location estimation of malicious nodes in mobile WiFi/802.11 networks

Hyperbolic position bounding (HPB) provides a mechanism to probabilistically delimit the location of a wireless network malicious insider to a candidate area. A large scale path loss model is used to construct a probable distance difference range between a rogue transmitter and a pair of trusted receivers. Hyperbolas are constructed at the minimum and maximum bounds of this range to delineate the position of a rogue with a given confidence level. We describe an outdoor experiment with a WiFi/802.11 network. Measured received signal strength (RSS) values, as well as path loss parameters obtained from signal propagation losses, are used by HPB to bound the location of a mobile transmitter within the WiFi/802.11 network with a degree of confidence. Experimental results are compared against prior simulation results and found to be consistent.

Probabilistic Evidence Aggregation for Malicious Node Position Bounding in Wireless Networks

Hyperbolic position bounding of malicious devices aims to estimate the location of a wireless network rogue insider that transmits an attack message containing falsified information to mislead honest nodes. A probabilistic path loss model is used to construct an area in Euclidian space bounded by minimum and maximum distance difference hyperbolas between each pair of trusted receivers. This hyperbolic area is said to contain the rogue insider with a degree of confidence. We explore the combination of evidence provided by a set of multiple receiver pairs supporting the intersection of their hyperbolic space. We propose a novel heuristic scheme to aggregate area probability so that the combined degree of confidence ascribed to the intersecting space is computed according to a paradigm of supportive rather than competitive evidence. Performance evaluation concludes that our aggregation model yields a probability distribution better fitted to experimental location estimation results than a redistributive paradigm.