1,720,961 research outputs found
Non Intrusive Wi-Fi CSI Obfuscation Against Active Localization Attacks
No full textChannel State Information (CSI) based localization with 802.11 has been proven feasible in multiple scenarios and is becoming a serious threat to people privacy in work spaces, at home, and maybe even outdoors, even if outdoors experiments proving the feasibility are still not available. Countering unauthorized localization without hampering communications is a nontrivial task, although some very recent works suggest that it is feasible with marginal modification of the 802.11 transmission chain, but this requires modifying 802.11 devices. Furthermore, if the attacker controls two devices and not only a receiver, transmission side signal manipulation cannot help. This work explores the possibility of countering CSI based localization with an active device that, instead of jamming signals to avoid that a malicious receiver exploits CSI information to locate a person, superimpose on frames a copy of the same frame signal whose goal is not destroying reception as in jamming, but only obfuscate the location relevant information carried by the CSI. A prototype implementation and early results looks promising; they show feasibility of location obfuscation with high efficiency and excellent preservation of communication performance, paving the road for further research and improved users privacy
Integrating CSI Sensing in Wireless Networks: Challenges to Privacy and Countermeasures
Full text linkThe path toward 6G is still long and blurred, but a few key points seem to be already decided: integration of many different access networks; adoption of massive MIMO technologies; use of frequencies above current radio spectrum up to THz and beyond; and inclusion of artificial intelligence and machine learning in standard management and operations. One additional point that is less discussed, but seems key for success, is the advanced use of channel state information (CSI) for both equalization and decoding purposes as well as for sensing ones. CSI-based sensing promises a plethora of new applications and a quantum leap in service personalization and customer-centric network management. At the same time, CSI analysis, being based on the physical characteristics of the propagated signal, poses novel threats to people's privacy and security: No software-based solution or cryptographic method above the physical layer can prevent the analysis of CSI. CSI analysis can reveal people's position or activity, allow tracking them, and discover details on the environment that today can be seen only with cameras or radars. In this article, we discuss the current status of CSI-based sensing and present some technologies that can protect people's privacy and at the same time allow legitimate use of the information carried by the CSI to offer better services
On the Implementation of Location Obfuscation in openwifi and Its Performance
Full text linkWi-Fi sensing as a side-effect of communications is opening new opportunities for smart services integrating communications with environmental properties, first and foremost the position of devices and people. At the same time, this technology represents an unprecedented threat to people’s privacy, as personal information can be collected directly at the physical layer without any possibility to hide or protect it. Several works already discussed the possibility of safeguarding users’ privacy without hampering communication performance. Usually, some signal pre-processing at the transmitter side is needed to introduce pseudo-random (artificial) patterns in the channel response estimated at the receiver, preventing the extraction of meaningful information from the channel state. However, there is currently just one implementation of such techniques in a real system (openwifi), and it has never been tested for performance. In this work, we present the implementation of a location obfuscation technique within the openwifi project that enables fine manipulation of the radio signal at transmitter side and yields acceptable, if not good, performance. The paper discusses the implementation of the obfuscation subsystem, its performance, possible improvements, and further steps to allow authorized devices to “de-obfuscate” the signal and retrieve the sensed information
WIP: Analysis of feasible topologies for backhaul mesh networks
Full text linkMesh backhauls are getting attention for 5G networks, but not only. A backhaul mesh is attractive due to its multiple potential paths that grants redundancy and robustness. The real topology and its properties, however, is heavily influenced by the characteristics of the place where it is deployed, a fact that is rarely taken into account by scientific literature, mainly due to the lack of detailed topographic data. This WIP analyzes the impact of true topography on small backhaul meshes in nine different locations in Italy. Initial results stress how true data influence results and can help designing better networks and better services
Improving BGP convergence with Fed4FIRE+ experiments
No full textThe Border Gateway Protocol (BGP) is the single routing protocol that glues the Internet together. Its performance, especially the convergence speed after path changes, is key to global efficiency, also in light of the fact that the number of Autonomous Systems (ASes) and Subnets has reached a level that makes path changes a frequent event. This work presents a testbed-based experimental analysis of BGP convergence time under different hypothesis of Minimum Route Advertisement Interval (MRAI) setting and a proposal to improve it by setting MRAI based on the topological position of the ASes. MRAI is a timer that regulates the frequency of successive UPDATE messages sent by a BGPs router for a given route and destination. The work is based on the modifications of the BIRD BGP daemon and shows that it is possible to execute experiments on testbeds with topologies that have Internet-like characteristics scaling up to thousands of ASes
Exact Distributed Load Centrality Computation: Algorithms, Convergence, and Applications to Distance Vector Routing
Full text linkMany optimization techniques for networking protocols take advantage of topological information to improve performance. Often, the topological information at the core of these techniques is a centrality metric such as the Betweenness Centrality (BC) index. BC is, in fact, a centrality metric with many well-known successful applications documented in the literature, from resource allocation to routing. To compute BC, however, each node must run a centralized algorithm and needs to have the global topological knowledge; such requirements limit the feasibility of optimization procedures based on BC. To overcome restrictions of this kind, we present a novel distributed algorithm that requires only local information to compute an alternative similar metric, called Load Centrality (LC). We present the new algorithm together with a proof of its convergence and the analysis of its time complexity. The proposed algorithm is general enough to be integrated with any distance vector (DV) routing protocol. In support of this claim, we provide an implementation on top of Babel, a real-world DV protocol. We use this implementation in an emulation framework to show how LC can be exploited to reduce Babel's convergence time upon node failure, without increasing control overhead. As a key step towards the adoption of centrality-based optimization for routing, we study how the algorithm can be incrementally introduced in a network running a DV routing protocol. We show that even when only a small fraction of nodes participate in the protocol, the algorithm accurately ranks nodes according to their centrality
Platooning Maneuvers in Vehicular Networks: A Distributed and Consensus-Based Approach
No full textCooperative driving is an essential component of future intelligent road systems. It promises greater safety, reducing accidents due to drivers distraction, improved infrastructure utilization, and fuel consumption reduction with platooning applications. Proper platoon management requires inter-vehicular communication (IVC), longitudinal control and lateral control for stability and safety, and proper application protocols and algorithms to manage platoons and perform coordinated maneuvers. This paper shows, how a longitudinal controller based on distributed consensus can, at the same time, guarantee stability and performance in regime platoon operations, and be at the hearth of maneuvering protocols and algorithms, as it remains stable in face of changes of platoon topology and control gains. The adoption of a single control algorithm for two fundamental tasks greatly simplify the overall design of the system and improves stability and safety as it is not required to switch between different controllers during platoon operation. The theoretical properties are proven in the first part of the paper. The second part of the paper is devoted to its implementation in a state-of-the-art mobility and IVC simulator, which is used for an extensive experimental campaign showing the dynamic properties of the system and its performance in a set of typical platoon maneuvers as join, leave, and inclusion of a vehicle in the middle of the platoon. All simulations include realistic details of the vehicle dynamics (mass, dimensions, power train dynamics) as well as extremely detailed modeling of the communication network, from IEEE 802.11p protocol details, to collisions, packet errors, path loss and fading on the channel, and source-destination-based delays
On the Properties of Infective Flooding in Low-Duty-Cycle Networks
Full text linkBroadcasting information in a network is an important function in networking applications. In some networks, as wireless sensor networks or some ad-hoc networks it is so essential as to dominate the performance of the entire system. Exploiting some recent results based on the computation of the eigenvector centrality of nodes in the network graph and classical dynamic diffusion models on graphs, this paper derives a novel theoretical framework for efficient information broadcasting in mesh networks with low duty-cycling without the need to build a distribution tree. The model provides lower and upper stochastic bounds with high probability. We show that the lower bound is very close to the theoretical optimum and that a preliminary implementation provides results that are very close to the lower bound on classical graph models
An Experimental Study of CSI Management to Preserve Location Privacy
No full textPassive device-free localization of a person exploiting the Channel State Information (CSI) from Wi-Fi signals is quickly becoming a reality. While this capability would enable new applications and services, it also raises concerns about citizens' privacy. In this work, we propose a carefully-crafted obfuscating technique against one of such CSI-based localization methods. In particular, we modify the transmitted I/Q samples by leveraging an irreversible randomized sequence. I/Q symbol manipulation at the transmitter distorts the location-specific information in the CSI while preserving communication, so that an attacker can no longer derive information on user's location. We test this technique against a Neural Network (NN)-based localization system and show that the randomization of the CSI makes undesired localization practically unfeasible. Both the localization system and the randomization CSI management are implemented in real devices. The experimental results obtained in our laboratory show that the considered localization method (first proposed in an MSc thesis) works smoothly regardless of the environment, and that adding random information to the CSI mess up the localization, thus providing the community with a system that preserve location privacy and communication performance at the same time
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