103 research outputs found

    Vehicular Systems Technologies: Challenges and Trends Across Transportation Means

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    The work is supported by the Spanish Ministry of Science, Innovation and Universities, under the Ramon y Cajal Program (Grant No. RYC-2017-23823) and the project PERSEIDES (Grant No.TIN2017-86885-R); the BBVA Foundation, under the 2018 Leonardo Grant for Researchers and Cultural Creators; and by the European Commission, under the projects IoTCrawler (Grant No. 779852), 5G-MOBIX (Grant No. 825496) and Pharaon (Grant No. 857188). First of all, we would like to thank all researchers who submitted articles to this special issue for their excellent contributions. We are also grateful to all reviewers who helped in the evaluation of the manuscripts and made valuable suggestions to improve the quality of contributions. We would like to acknowledge the editorial board of Electronics, who invited us to guest edit this special issue. We are also grateful to the Electronics Editorial Office staff who worked thoroughly to maintain the rigorous peer-review schedule and timely publication

    Zero-Knowledge Proof-of-Identity: Sybil-Resistant, Anonymous Authentication on Permissionless Blockchains and Incentive Compatible, Strictly Dominant Cryptocurrencies

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    Zero-Knowledge Proof-of-Identity from trusted public certificates (e.g., national identity cards and/or ePassports; eSIM) is introduced here to permissionless blockchains in order to remove the inefficiencies of Sybil-resistant mechanisms such as Proof-of-Work (i.e., high energy and environmental costs) and Proof-of-Stake (i.e., capital hoarding and lower transaction volume). The proposed solution effectively limits the number of mining nodes a single individual would be able to run while keeping membership open to everyone, circumventing the impossibility of full decentralization and the blockchain scalability trilemma when instantiated on a blockchain with a consensus protocol based on the cryptographic random selection of nodes. Resistance to collusion is also considered. Solving one of the most pressing problems in blockchains, a zk-PoI cryptocurrency is proved to have the following advantageous properties: - an incentive-compatible protocol for the issuing of cryptocurrency rewards based on a unique Nash equilibrium - strict domination of mining over all other PoW/PoS cryptocurrencies, thus the zk-PoI cryptocurrency becoming the preferred choice by miners is proved to be a Nash equilibrium and the Evolutionarily Stable Strategy - PoW/PoS cryptocurrencies are condemned to pay the Price of Crypto-Anarchy, redeemed by the optimal efficiency of zk-PoI as it implements the social optimum - the circulation of a zk-PoI cryptocurrency Pareto dominates other PoW/PoS cryptocurrencies - the network effects arising from the social networks inherent to national identity cards and ePassports dominate PoW/PoS cryptocurrencies - the lower costs of its infrastructure imply the existence of a unique equilibrium where it dominates other forms of paymentComment: 2.1: Proof-of-Personhood Considered Harmful (and Illegal); 4.1.5: Absence of Active Authentication; 4.2.6: Absence of Active Authentication; 4.2.7: Removing Single-Points of Failure; 4.3.2: Combining with Non-Zero-Knowledge Authentication; 4.4: Circumventing the Impossibility of Full Decentralizatio

    Which attacks lead to hazards? Combining safety and security analysis for cyber-physical systems

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    Cyber-Physical Systems (CPS) are exposed to a plethora of attacks and their attack surface is only increasing. However, whilst many attack paths are possible, only some can threaten the system's safety and potentially lead to loss of life. Identifying them is of essence. We propose a methodology and develop a tool-chain to systematically analyse and enumerate the attacks leading to safety violations. This is achieved by lazily combining threat modelling and safety analysis with formal verification and with attack graph analysis. We also identify the minimum sets of privileges that must be protected to preserve safety. We demonstrate the effectiveness of our methodology to discover threat scenarios by applying it to a Communication Based Train Control System. Our design choices emphasise compatibility with existing safety and security frameworks, whilst remaining agnostic to specific tools or attack graphs representations

    MP-CFM: MPTCP-Based communication functional module for next generation ERTMS

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    184 p. El contenido de los capítulos 4,5,6,7,8 y 9 está sujeto a confidencialidadEl Sistema Europeo de Gestión del Tráfico Ferroviario (ERTMS, por sus siglasen inglés), fue originalmente diseñado para los ferrocarriles europeos. Sinembargo, a lo largo de las dos últimas décadas, este sistema se ha convertidoen el estándar de-facto para los servicios de Alta Velocidad en la mayoría depaíses desarrollados.El sistema ERTMS se compone de tres subsistemas principales: 1) el Sistemade Control Ferroviario Europeo (ETCS, por sus siglas en inglés), que actúacomo aplicación de señalización; 2) el sistema Euroradio, que a su vez estádividido en dos subsistemas, el Módulo de Seguridad Funcional (SFM, porsus siglas en inglés), y el Módulo de Comunicación Funcional (CFM, porsus siglas en inglés); y 3) el sistema de comunicaciones subyacente, GSM-R,que transporta la información intercambiada entre el sistema embarcado enel tren (OBU, por sus siglas en inglés) y el Centro de Bloqueo por Radio(RBC, por sus siglas en inglés). El sistema de señalización ETCS soporta tresniveles dependiendo del nivel de prestaciones soportadas. En el nivel 3 seintroduce la posibilidad de trabajar con bloques móviles en lugar de bloquesfijos definidos en la vía. Esto implica que la distancia de avance entre dos trenesconsecutivos puede ser reducida a una distancia mínima en la que se garanticela seguridad del servicio, aumentando por tanto la capacidad del corredorferroviario. Esta distancia de seguridad viene determinada por la combinaciónde la distancia de frenado del tren y el retraso de las comunicaciones deseñalización. Por lo tanto, se puede afirmar que existe una relación directaentre los retrasos y la confiabilidad de las transmisiones de las aplicaciones deseñalización y la capacidad operacional de un corredor ferroviario. Así pues,el estudio y mejora de los sistemas de comunicaciones utilizados en ERTMSjuegan un papel clave en la evolución del sistema ERTMS. Asimismo, unaoperatividad segura en ERTMS, desde el punto de vista de las comunicacionesimplicadas en la misma, viene determinada por la confiabilidad de lascomunicaciones, la disponibilidad de sus canales de comunicación, el retrasode las comunicaciones y la seguridad de sus mensajes.Unido este hecho, la industria ferroviaria ha venido trabajando en ladigitalización y la transición al protocolo IP de la mayor parte de los sistemasde señalización. Alineado con esta tendencia, el consorcio industrial UNISIGha publicado recientemente un nuevo modelo de comunicaciones para ERTMSque incluye la posibilidad, no solo de operar con el sistema tradicional,basado en tecnología de conmutación de circuitos, sino también con un nuevosistema basado en IP. Esta tesis está alineada con el contexto de migraciónactual y pretende contribuir a mejorar la disponibilidad, confiabilidad yseguridad de las comunicaciones, tomando como eje fundamental los tiemposde transmisión de los mensajes, con el horizonte puesto en la definición deuna próxima generación de ERTMS, definida en esta tesis como NGERTMS.En este contexto, se han detectado tres retos principales para reforzar laresiliencia de la arquitectura de comunicaciones del NGERTMS: 1) mejorarla supervivencia de las comunicaciones ante disrupciones; 2) superar laslimitaciones actuales de ERTMS para enviar mensajes de alta prioridad sobretecnología de conmutación de paquetes, dotando a estos mensajes de un mayorgrado de resiliencia y menor latencia respecto a los mensajes ordinarios; y3) el aumento de la seguridad de las comunicaciones y el incremento de ladisponibilidad sin que esto conlleve un incremento en la latencia.Considerando los desafíos previamente descritos, en esta tesis se proponeuna arquitectura de comunicaciones basada en el protocolo MPTCP, llamadaMP-CFM, que permite superar dichos desafíos, a la par que mantener laretrocompatibilidad con el sistema de comunicaciones basado en conmutaciónde paquetes recientemente propuesto por UNISIG. Hasta el momento, esta esla primera vez que se propone una arquitectura de comunicaciones completacapaz de abordar los desafíos mencionados anteriormente. Esta arquitecturaimplementa cuatro tipos de clase de servicio, los cuales son utilizados porlos paquetes ordinarios y de alta prioridad para dos escenarios distintos; unescenario en el que ambos extremos, el sistema embarcado o OBU y el RBC,disponen de múltiples interfaces de red; y otro escenario transicional en el cualel RBC sí tiene múltiples interfaces de red pero el OBU solo dispone de unaúnica interfaz. La arquitectura de comunicaciones propuesta para el entornoferroviario ha sido validada mediante un entorno de simulación desarrolladopara tal efecto. Es más, dichas simulaciones demuestran que la arquitecturapropuesta, ante disrupciones de canal, supera con creces en términos derobustez el sistema diseñado por UNISIG. Como conclusión, se puede afirmarque en esta tesis se demuestra que una arquitectura de comunicaciones basadade MPTCP cumple con los exigentes requisitos establecidos para el NGERTMSy por tanto dicha propuesta supone un avance en la evolución del sistema deseñalización ferroviario europeo

    Performance Analysis of Train Communication Systems

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    Trains are considered as a highly efficient transport mode which generate significant challenges in terms of their communication systems. For improved safety, to cope with the expected rapid increase in traffic, and to meet customer demands, an enhanced and reliable communication system is required for high-speed trains (HSRs). Mobile phone and laptop users would like to make use of the non-negligible time that they spend commuting but current HSR communication systems have a foreseeable end to their lifetime and a reliable, efficient, and fast communication replacement system has become essential. Encouraged by the use of existing power line networks for communication purposes, this research investigates the possibility of developing a train communication system based on the use of overhead line equipment (OLE). The ABCD transfer line model is developed to represent the transfer function of the OLE channel and is evaluated using computer simulations. The simulations of the OLE system used are based on orthogonal frequency division multiplexing as the chosen modulation scheme. Within the train, for the provision of broadband services, developing a reliable communication system which is a combination of power line communication and optical wireless communication services using visible light communication (VLC) is considered. Mathematical methods were developed for these networks to assess the overall capacities and outage probabilities of the hybrid systems. Derivation of such analytical expressions offered opportunities to investigate the impact of several system parameters on the performance of the system. To assess the possibility of improving the performance of the proposed integrated systems, their performance in the presence of different relaying protocols has been comprehensively analyzed in terms of capacity and outage probability. This thesis studied the outage probability and energy per bit consumption performance of different relaying protocols over the VLC channel. Accurate analytical expressions for the overall outage probability and energyper-bit consumption of the proposed system configurations, including the single-hop and multi-hop approaches were derived. It was found that the transfer function of the OLE channel can be represented by the two-port network model. It was also revealed that transmission over OLE is negatively affected by the speed of the train, frequency, and length of the OLE link. In train, relay-based communication systems can provide reliable connectivity to the end-user. However, choosing an optimal system configuration can enhance system performance. It was also shown that increasing relay numbers on the network contributes to the total power consumption of the system

    Impact of Sparse and Dense Deployment of Nodes Under Different Propagation Models in Manets

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    Mobile Ad-hoc Network (MANET) is the most emerging and fast-expanding technology in the last two decades. One of the major issues and challenging areas in MANET is the process of routing due to dynamic topologies and high mobility of mobile nodes. The efficiency and accuracy of a protocol depend on many parameters in these networks. In addition to other parameters node velocity and propagation models are among them. Calculating signal strength at the receiver is the responsibility of a propagation model while the mobility of nodes is responsible for the topology of the network. A huge amount of loss in performance is occurred due to the variation of signal strength at the receiver and obstacles between transmissions. In this paper,it has been analyzed to check the impact of different propagation models on the performance of Optimized Link State Routing (OLSR) in Sparse and Dense scenarios in MANET. The simulation has been carried out in NS-2 by using performance metrics as average packet drop average latency and average Throughput. The results predicted that propagation models and mobility have a strong impact on the performance of OLSR in considered scenarios

    Systems engineering framework for railway control & safety systems

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    Traditional railway signalling systems have been based on fixed block train separation and line-of-sight signals to control the movement of trains. This has historically led to a segregation of both the functionality and the development of sub-systems such as signalling, rolling stock and control centres, all following a sequential design-based approach in their development. These traditional systems are becoming increasingly redundant as the railway industry embraces modern systems such as the higher levels of ERTMS and CBTC. With the change to these complex systems of systems also comes a change in the way in which the industry must develop and deliver projects. The railway industry has, at times, struggled to embrace systems engineering, as it is perceived to run against the safety-focused design approach that rightfully enjoys a high status within the industry. Many engineers in the industry who are familiar with the traditional design based approach also struggle with relating the new systems to the traditional principles that they are used to. This research investigates the feasibility of producing a systems engineering framework that can be applied to all forms of Railway Control & Safety (RCS) systems in order to simplify their development and delivery

    Interference Reduction in Mobile Ad Hoc and Sensor Networks

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    There are still a lot of open questions in the field of MANETs and sensor networks. If a topology incurs a large interference, either many communication signals sent by nodes will collide, or the network may experience a serious delay at delivering the data for some nodes, and even consume more energy. So, we reach to the conclusion that interference imposes a potential negative impact on the performance of wireless networks. In the last few years, researchers actively explored topology control approaches for such networks. The motivation of topology control (TC) is to maintain the connectivity of the network, reduce the node degree and thereby reduce the interference, and reduce power consumption in the sensor nodes. Some literatures have pointed out that a node can interfere with another node even if it is beyond its communication range. To improve the network performance, designing topology control algorithms with consideration of interference is imminent and necessary. Since, it leads to fewer collisions and packet retransmissions, which indirectly reduces the power consumption and extends the lifetime of the network. In this thesis, we propose a new interference-aware connected dominating set-based topology construction algorithm, namely, IACDS algorithm, a simple, distributed, interference-aware and energy-efficient topology construction mechanism that finds a sub-optimal Connected Dominating Set (CDS) to turn unnecessary nodes off while keeping the network connected and providing complete communication coverage with minimum interference. IACDS algorithm utilizes a weighted (distance-energy-interference)-based metric that permits the network operator to trade off the lengths of the branches (distance) for the robustness and durability of the topology (energy and interference)

    SPD-safe: Secure administration of railway intelligent transportation systems

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    The railway transport system is critical infrastructure that is exposed to numerous manmade and natural threats, thus protecting this physical asset is imperative. Cyber security, privacy, and dependability (SPD) are also important, as the railway operation relies on cyber-physical systems (CPS) systems. This work presents SPD-Safe—an administration framework for railway CPS, leveraging artificial intelligence for monitoring and managing the system in real-time. The network layer protections integrated provide the core security properties of confidentiality, integrity, and authentication, along with energy-aware secure routing and authorization. The effectiveness in mitigating attacks and the efficiency under normal operation are assessed through simulations with the average delay in real equipment being 0.2–0.6 s. SPD metrics are incorporated together with safety semantics for the application environment. Considering an intelligent transportation scenario, SPD-Safe is deployed on railway critical infrastructure, safeguarding one outdoor setting on the railway’s tracks and one in-carriage setting on a freight train that contains dangerous cargo. As demonstrated, SPD-Safe provides higher security and scalability, while enhancing safety response procedures. Nonetheless, emergence response operations require a seamless interoperation of the railway system with emergency authorities’ equipment (e.g., drones). Therefore, a secure integration with external systems is considered as future work
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