Privacy Implications of In-Network Aggregation Mechanisms for VANETs

Research on vehicular ad hoc networks (VANETs) is active and ongoing. Proposed applications range from safety applications, and traffic efficiency applications to entertainment applications. Common to many applications is the need to disseminate possibly privacy-sensitive information, such as location and speed information, over larger distances. In-network aggregation is a promising technology that can help to make such privacy-sensitive information only available in the direct vicinity of vehicles instead of communicating it over larger areas. Further away, only aggregated information that is not privacy-relevant anymore will be known. At the same time, aggregation mechanisms help to cope with the limited available wireless bandwidth. However, the exact privacy properties of aggregation mechanisms have still not been thoroughly researched. In this paper, we propose a metric to measure privacy enhancements provided by in-network aggregation and use it to compare existing schemes

Smart Directional Data Aggregation in VANETs

International audienceThe ultimate goal of a Traffic Information System (TIS) consists in properly informing vehicles about road traffic conditions in order to reduce traffic jams and consequently CO2 emission while increasing the user comfort. Therefore, the design of an efficient aggregation protocol that combines correlated traffic information like location, speed and direction known as Floating Car Data (FCD) is of paramount importance. In this paper, we introduce a new TIS data aggregation protocol called Smart Directional Data Aggregation (SDDA) able to decrease the network overload while obtaining high accurate information on traffic conditions for large road sections. To this end, we introduce three levels of messages filtering: (i) filtering all FCD messages before the aggregation process based on vehicle directions and road speed limitations, (ii) integrating a suppression technique in the phase of information gathering in order to eliminate the duplicate data, and (iii) aggregating the filtered FCD data and then disseminating it to other vehicles. The performed experiments show that the SDDA outperforms existing approaches in terms of effectiveness and efficiency

Location Aware Data Aggregation for Efficient Message Dissemination in Vehicular Ad Hoc Networks

An intelligent location-aware data aggregation mechanism for real-time observation, estimation, and efficient dissemination of any kind of traffic information in vehicular ad hoc networks (VANETs) is presented in this paper. The mechanism introduces a location awareness algorithm, enabling spatiotemporal database indexing and providing the location context of the messages without the use of advanced positioning systems such as satellite navigation and digital maps. Intelligent passive clustering and adaptive broadcasting are used to minimize the number of messages exchanged, packet collisions, and network load. The incoming messages are fused by a Kalman filter, allowing the description of the traffic-related information as a system characterized by as many variables as needed, depending on the application design. The scheme allows the comparison of aggregates and single observations, which enables their merging and better overall accuracy. Old information in aggregates is removed by real-time database refreshing, thus leaving only newer relevant information for the driver to make real-time decisions in traffic. The mechanism is generic and can be used for any kind of VANET information. It is evaluated by extensive simulations to show the efficiency and accuracy

Modeling In-Network Aggregation in VANETs

The multitude of applications envisioned for vehicular ad hoc networks requires efficient communication and dissemination mechanisms to prevent network congestion. In-network data aggregation promises to reduce bandwidth requirements and enable scalability in large vehicular networks. However, most existing aggregation schemes are tailored to specific applications and types of data. Proper comparative evaluation of different aggregation schemes is difficult. Yet, comparability is essential to properly measure accuracy, performance, and efficiency. We outline a modeling approach for VANET aggregation schemes to achieve objective comparability. Our modeling approach consists of three models, which provide different perspectives on an aggregation scheme. The generalized architecture model facilitates categorization of aggregation schemes. The aggregation information flow model supports analysis of where information is aggregated by a scheme. The aggregation state graph models how knowledge about the road network and its environment is represented by a scheme. Furthermore, it facilitates error estimation with respect to the ground truth. We apply each modeling approach to existing aggregation schemes from the literature and highlight strengths, as well as weaknesses, that can be used as a starting point for designing a more generic aggregation scheme

VANET-enabled eco-friendly road characteristics-aware routing for vehicular traffic

There is growing awareness of the dangers of climate change caused by greenhouse gases. In the coming decades this could result in numerous disasters such as heat-waves, flooding and crop failures. A major contributor to the total amount of greenhouse gas emissions is the transport sector, particularly private vehicles. Traffic congestion involving private vehicles also causes a lot of wasted time and stress to commuters. At the same time new wireless technologies such as Vehicular Ad-Hoc Networks (VANETs) are being developed which could allow vehicles to communicate with each other. These could enable a number of innovative schemes to reduce traffic congestion and greenhouse gas emissions. 1) EcoTrec is a VANET-based system which allows vehicles to exchange messages regarding traffic congestion and road conditions, such as roughness and gradient. Each vehicle uses the messages it has received to build a model of nearby roads and the traffic on them. The EcoTrec Algorithm then recommends the most fuel efficient route for the vehicles to follow. 2) Time-Ants is a swarm based algorithm that considers not only the amount of cars in the spatial domain but also the amoumt in the time domain. This allows the system to build a model of the traffic congestion throughout the day. As traffic patterns are broadly similar for weekdays this gives us a good idea of what traffic will be like allowing us to route the vehicles more efficiently using the Time-Ants Algorithm. 3) Electric Vehicle enhanced Dedicated Bus Lanes (E-DBL) proposes allowing electric vehicles onto the bus lanes. Such an approach could allow a reduction in traffic congestion on the regular lanes without greatly impeding the buses. It would also encourage uptake of electric vehicles. 4) A comprehensive survey of issues associated with communication centred traffic management systems was carried out

Application of improved you only look once model in road traffic monitoring system

The present research focuses on developing an intelligent traffic management solution for tracking the vehicles on roads. Our proposed work focuses on a much better you only look once (YOLOv4) traffic monitoring system that uses the CSPDarknet53 architecture as its foundation. Deep-sort learning methodology for vehicle multi-target detection from traffic video is also part of our research study. We have included features like the Kalman filter, which estimates unknown objects and can track moving targets. Hungarian techniques identify the correct frame for the object. We are using enhanced object detection network design and new data augmentation techniques with YOLOv4, which ultimately aids in traffic monitoring. Until recently, object identification models could either perform quickly or draw conclusions quickly. This was a big improvement, as YOLOv4 has an astoundingly good performance for a very high frames per second (FPS). The current study is focused on developing an intelligent video surveillance-based vehicle tracking system that tracks the vehicles using a neural network, image-based tracking, and YOLOv4. Real video sequences of road traffic are used to test the effectiveness of the method that has been suggested in the research. Through simulations, it is demonstrated that the suggested technique significantly increases graphics processing unit (GPU) speed and FSP as compared to baseline algorithms

Data-centric trust in ephemeral networks

New network types require new security concepts. Surprisingly, trust – the ultimate goal of security – has not evolved as much as other concepts. In particular, the traditional notion of building trust in entities seems inadequate in an ephemeral environment where contacts among nodes are often short-lived and non-recurrent. It is actually the trustworthiness of the data that entities generate that matters most in these ephemeral networks. And what makes things more interesting is the continuous "humanization" of devices, by making them reflect more closely their owners' preferences, including the human sense of costs. Hence, in this thesis we study the notion of data-centric trust in an ephemeral network of rational nodes. The definition of a new notion requires specifying the corresponding basis, measures, and raison d'être. In the following chapters, we address these issues. We begin by defining the system and security models of an example ephemeral network, namely a vehicular network. Next, we delve into the subject of revocation in vehicular networks, before creating and analyzing a game-theoretic model of revocation, where the notion of cost-aware devices makes its first appearance in this thesis. This model not only makes possible the comparison of different revocation mechanisms in the literature, but also leads to the design of an optimal solution, the RevoGame protocol. With the security architecture in place, we formally define data-centric trust and compare several mechanisms for evaluating it. Notably, we apply the Dempster-Shafer Theory to cases of high uncertainty. Last but not least, we show that data-centric trust can reduce the privacy loss resulting from the need to establish trust. We first create a model of the trust-privacy tradeoff and then analyze it with game theory, in an environment of privacy-preserving entities. Our analysis shows that proper incentives can achieve this elusive tradeoff

Scalable Network Design and Management with Decentralized Software-defined Networking

Network softwarization is among the most significant innovations of computer networks in the last few decades. The lack of uniform and programmable interfaces for network management led to the design of OpenFlow protocol for the university campuses and enterprise networks. This breakthrough coupled with other similar efforts led to an emergence of two complementary but independent paradigms called software-defined networking (SDN) and network function virtualization (NFV). As of this writing, these paradigms are becoming the de-facto norms of wired and wireless networks alike. This dissertation mainly addresses the scalability aspect of SDN for multiple network types. Although centralized control and separation of control and data planes play a pivotal role for ease of network management, these concepts bring in many challenges as well. Scalability is among the most crucial challenges due to the unprecedented growth of computer networks in the past few years. Therefore, we strive to grapple with this problem in diverse networking scenarios and propose novel solutions by harnessing capabilities provided by SDN and other related technologies. Specifically, we present the techniques to deploy SDN at the Internet scale and to extend the concepts of softwarization for mobile access networks and vehicular networks. Multiple optimizations are employed to mitigate latency and other overheads that contribute to achieve performance gains. Additionally, by taking care of sparse connectivity and high mobility, the intrinsic constraints of centralization for wireless ad-hoc networks are addressed in a systematic manner. The state-of-the-art virtualization techniques are coupled with cloud computing methods to exploit the potential of softwarization in general and SDN in particular. Finally, by tapping into the capabilities of machine learning techniques, an SDN-based solution is proposed that inches closer towards the longstanding goal of self-driving networks. Extensive experiments performed on a large-scale testbed corroborates effectiveness of our approaches

Nuevas herramientas de seguridad cooperativa para redes Ad-Hoc vehiculares

La seguridad vial es un tema de interés general. Pese al éxito de las medidas aplicadas hasta el momento, las cifras de siniestralidad vial en la Unión Europea siguen siendo inaceptables. Si a la fundamental cuestión de los accidentes se le suman los atascos, la conclusión es que las carreteras conllevan una compleja problemática que requiere una solución urgente tanto por las consecuencias en las pérdidas de vidas, como por su negativo efecto en la economía y en el medioambiente. No es raro pues que el problema sea objeto de creciente atención, y que exista un Programa de Acción Europeo de Seguridad Vial que se centra en: mentalizar a los usuarios para que tengan un comportamiento más responsable (mayor cumplimiento de la normativa y menor tolerancia ante los comportamientos peligrosos), aumentar la seguridad de los vehículos mediante el apoyo a los avances técnicos y mejorar las infraestructuras viales gracias a las Tecnologías de la Información y la Comunicación. Como propuesta para este último objetivo, surgen las redes ad-hoc vehiculares o VANETs (Vehicular Ad-hoc NETworks), en las que los vehículos se comunican entre sí para prevenir y/o evitar circunstancias adversas en las carreteras y lograr una gestión más eficiente del tráfico. Para que este tipo de redes llegue a convertirse en una tecnología real que garantice la seguridad pública en las carreteras, son necesarias diversas herramientas de seguridad de las comunicaciones que las protejan de los posibles tipos de ataques, entre los que destacan: ataques a la red que pongan en peligro su conectividad, ataques a la privacidad y anonimato de los usuarios, y ataques al contenido de la información que modifiquen su contenido. El propósito fundamental de la presente memoria es la propuesta de nuevas herramientas que permitan proteger las VANETs frente a dichos ataques, asegurando en la medida de lo posible que la información generada en ellas, así como su retransmisión se realice correctamente. Como resultado principal de esta investigación, y en colaboración con otras investigaciones, destaca VAiPho (VANET in Phones), que es una herramienta para la asistencia a la conducción que permite crear una red ad-hoc vehicular real y segura, utilizando únicamente teléfonos móviles inteligentes. En su estado actual, VAiPho hace factible el despliegue de las VANETs principalmente en entornos urbanos y con aplicación en detección de atascos y plazas de aparcamiento libres y de vehículo aparcado. Dicha herramienta es el origen de una patente de la Universidad de La Laguna ya licenciada a una empresa. Esta Tesis incluye un análisis de diversos mecanismos de seguridad necesarios para desplegar una VANET confiable y funcional en la que los nodos sean totalmente autónomos e independientes, proponiéndose una serie de nuevos protocolos, algunos de los cuales hacen uso de soluciones basadas en Criptografía. La primera parte de esta memoria presenta un estudio de diferentes técnicas de fomento de la cooperación para animar a los usuarios a participar en las funcionalidades básicas de la red como por ejemplo la retransmisión de paquetes de información, ya sea de valor añadido o de seguridad vial. Nuestro principal objetivo en esta parte es que los nodos sean capaces de desplegar la VANET con un alto nivel de productividad, permitiendo el intercambio de información sobre los eventos que surgen en la carretera, e incrementando el alcance del rango de cobertura de los nodos dentro de la red. En concreto se presentan diferentes estrategias para motivar a los nodos a participar en la retransmisión correcta de paquetes, además de para asegurar una mayor disponibilidad y calidad de la red. En la segunda parte del documento se discute la necesidad de proteger el contenido de la información retransmitida en la VANET mediante técnicas de agregación de datos. Cuando los nodos reciben un paquete no son capaces de determinar si el nodo que lo generó tenía buena o mala intención, por lo que no les resulta fácil descubrir si la información que contiene es fiable o no. Por tanto, un protocolo que garantice la veracidad de la información sin suponer un retardo importante es esencial para poder desplegar y asegurar el funcionamiento de este tipo de redes. En este trabajo se propone la verificación probabilística para mejorar la eficiencia del proceso. Además, con el objetivo de disminuir el tiempo necesario para generar la información, se utiliza una estructura de grupo que permite manejar de forma eficaz los paquetes agregados generados. Finalmente se presenta la implementación de algunos de los mecanismos pro\-pues\-tos en teléfonos móviles inteligentes. Los resultados obtenidos en entornos reales son usados para perfeccionar simulaciones NS-2 a gran escala, proporcionando una visión de los protocolos de seguridad que mejor se adaptan a las características de las VANETs. Además dicha implementación ofrece la posibilidad de desplegar una VANET real y segura de manera rápida y económic