20 research outputs found
Localizability of Wireless Sensor Networks: Beyond Wheel Extension
A network is called localizable if the positions of all the nodes of the
network can be computed uniquely. If a network is localizable and embedded in
plane with generic configuration, the positions of the nodes may be computed
uniquely in finite time. Therefore, identifying localizable networks is an
important function. If the complete information about the network is available
at a single place, localizability can be tested in polynomial time. In a
distributed environment, networks with trilateration orderings (popular in real
applications) and wheel extensions (a specific class of localizable networks)
embedded in plane can be identified by existing techniques. We propose a
distributed technique which efficiently identifies a larger class of
localizable networks. This class covers both trilateration and wheel
extensions. In reality, exact distance is almost impossible or costly. The
proposed algorithm based only on connectivity information. It requires no
distance information
Position certainty propagation: a location service for MANETs
International audienceLocalization in Mobile Ad-hoc Networks (MANETs) and Wireless Sensor Networks (WSNs) is an issue of great interest, especially in applications such as the IoT and VANETs. We propose a solution that overcomes two limiting characteristics of these types of networks. The first is the high cost of nodes with a location sensor (such as GPS) which we will refer to as anchor nodes. The second is the low computational capability of nodes in the network. The proposed algorithm addresses two issues; self-localization where each non-anchor node should discover its own position, and global localization where a node establishes knowledge of the position of all the nodes in the network. We address the problem as a graph where vertices are nodes in the network and edges indicate connectivity between nodes. The weights of edges represent the Euclidean distance between the nodes. Given a graph with at least three anchor nodes and knowing the maximum communication range for each node, we are able to localize nodes using fairly simple computations in a moderately dense graph
So near and yet so far: Distance-bounding attacks in wireless networks
Abstract. Distance-bounding protocols aim to prevent an adversary from pretending that two parties are physically closer than they really are. We show that proposed distance-bounding protocols of Hu, Perrig and Johnson (2003), Sastry, Shankar and Wagner (2003), and Čapkun and Hubaux (2005, 2006) are vulnerable to a guessing attack where the malicious prover preemptively transmits guessed values for a number of response bits. We also show that communication channels not optimized for minimal latency imperil the security of distance-bounding protocols. The attacker can exploit this to appear closer himself or to perform a relaying attack against other nodes. We describe attack strategies to achieve this, including optimizing the communication protocol stack, taking early decisions as to the value of received bits and modifying the waveform of transmitted bits. We consider applying distance-bounding protocols to constrained devices and evaluate existing proposals for distance bounding in ad hoc networks.