Reputation systems and secure communication in vehicular networks

A thorough review of the state of the art will reveal that most VANET applications rely on Public Key Infrastructure (PKI), which uses user certificates managed by a Certification Authority (CA) to handle security. By doing so, they constrain the ad-hoc nature of the VANET imposing a frequent connection to the CA to retrieve the Certificate Revocation List (CRL) and requiring some degree of roadside infrastructure to achieve that connection. Other solutions propose the usage of group signatures where users organize in groups and elect a group manager. The group manager will need to ensure that group members do not misbehave, i.e., do not spread false information, and if they do punish them, evict them from the group and report them to the CA; thus suffering from the same CRL retrieval problem. In this thesis we present a fourfold contribution to improve security in VANETs. First and foremost, Chains of Trust describes a reputation system where users disseminate Points of Interest (POIs) information over the network while their privacy remains protected. It uses asymmetric cryptography and users are responsible for the generation of their own pair of public and private keys. There is no central entity which stores the information users input into the system; instead, that information is kept distributed among the vehicles that make up the network. On top of that, this system requires no roadside infrastructure. Precisely, our main objective with Chains of Trust was to show that just by relying on people¿s driving habits and the sporadic nature of their encounters with other drivers a successful reputation system could be built. The second contribution of this thesis is the application simulator poiSim. Many¿s the time a new VANET application is presented and its authors back their findings using simulation results from renowned networks simulators like ns-2. The major issue with network simulators is that they were not designed with that purpose in mind and handling simulations with hundreds of nodes requires a massive processing power. As a result, authors run small simulations (between 50 and 100 nodes) with vehicles that move randomly in a squared area instead of using real maps, which rend unrealistic results. We show that by building tailored application simulators we can obtain more realistic results. The application simulator poiSim processes a realistic mobility trace produced by a Multi-agent Microscopic Traffic Simulator developed at ETH Zurich, which accurately describes the mobility patterns of 259,977 vehicles over regional maps of Switzerland for 24 hours. This simulation runs on a desktop PC and lasts approximately 120 minutes. In our third contribution we took Chains of Trust one step further in the protection of user privacy to develop Anonymous Chains of Trust. In this system users can temporarily exchange their identity with other users they trust, thus making it impossible for an attacker to know in all certainty who input a particular piece of information into the system. To the best of our knowledge, this is the first time this technique has been used in a reputation system. Finally, in our last contribution we explore a different form of communication for VANETs. The vast majority of VANET applications rely on the IEEE 802.11p/Wireless Access in Vehicular Environments (WAVE) standard or some other form of radio communication. This poses a security risk if we consider how vulnerable radio transmission is to intentional jamming and natural interferences: an attacker could easily block all radio communication in a certain area if his transmitter is powerful enough. Visual Light Communication (VLC), on the other hand, is resilient to jamming over a wide area because it relies on visible light to transmit information and ,unlike WAVE, it has no scalability problems. In this thesis we show that VLC is a secure and valuable form of communication in VANETs

An Empty Promise? Digital Democracy in the Smart City

The digital transformation affects every part of our societies and everyday lives, including the processes and structures of our democracies. On the one hand, information and communication technologies have the potential to lower the threshold for political communication and participation. On the other hand, they can be used for large-scale data collection and surveillance, posing a risk to the public sphere. This thesis investigates the impact of digitization on the legitimacy of democracy. It first develops a novel framework based on the theories of participatory and deliberative democracy, drawing on recent work on deliberative systems. On this basis, digital democracy is examined as a system, consisting of different engagement spaces and actors within the smart city. The smart city is a particularly fruitful testbed for digital democracy as it is based on the promise of applying a high density of digital technologies to facilitate civic participation as well as better service delivery and governance. Through an in-depth case study of the smart city of Amsterdam, this thesis not only reveals the legitimacy dilemmas of digital democracy in the smart city, but also illustrates the limits of applying participatorydeliberative systems theory on a digital democracy ecosystem. The analysis demonstrates design conflicts between different online engagement platforms within the digital democracy system, as well as conflicting objectives among the actors behind them. The findings do not support the claim that digitization negatively impacts democracy’s legitimacy in the smart city of Amsterdam through marketization, large-scale data collection, and surveillance, as some authors warn. However, a significant positive impact of digitization on democratic legitimacy, through higher levels of inclusiveness, empowerment, or civic influence, is also not confirmed. The findings show that digital technologies’ promise of facilitating large-scale citizen participation and deliberation in the smart city does not live up to the normative ideal. The results from Amsterdam are exposed to smart city and digital democracy experts across the globe to test their generalizability, demonstrating that, despite its shortcomings, Amsterdam’s extensive digital democracy system is far advanced in international comparison. What may appear a contradiction in fact illustrates that we are still in the early stages of development, with potential to enhance the legitimacy of digital democracy, both in the smart city of Amsterdam and beyond

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

Dynamic data placement and discovery in wide-area networks

The workloads of online services and applications such as social networks, sensor data platforms and web search engines have become increasingly global and dynamic, setting new challenges to providing users with low latency access to data. To achieve this, these services typically leverage a multi-site wide-area networked infrastructure. Data access latency in such an infrastructure depends on the network paths between users and data, which is determined by the data placement and discovery strategies. Current strategies are static, which offer low latencies upon deployment but worse performance under a dynamic workload. We propose dynamic data placement and discovery strategies for wide-area networked infrastructures, which adapt to the data access workload. We achieve this with data activity correlation (DAC), an application-agnostic approach for determining the correlations between data items based on access pattern similarities. By dynamically clustering data according to DAC, network traffic in clusters is kept local. We utilise DAC as a key component in reducing access latencies for two application scenarios, emphasising different aspects of the problem: The first scenario assumes the fixed placement of data at sites, and thus focusses on data discovery. This is the case for a global sensor discovery platform, which aims to provide low latency discovery of sensor metadata. We present a self-organising hierarchical infrastructure consisting of multiple DAC clusters, maintained with an online and distributed split-and-merge algorithm. This reduces the number of sites visited, and thus latency, during discovery for a variety of workloads. The second scenario focusses on data placement. This is the case for global online services that leverage a multi-data centre deployment to provide users with low latency access to data. We present a geo-dynamic partitioning middleware, which maintains DAC clusters with an online elastic partition algorithm. It supports the geo-aware placement of partitions across data centres according to the workload. This provides globally distributed users with low latency access to data for static and dynamic workloads.Open Acces

Social informatics

5th International Conference, SocInfo 2013, Kyoto, Japan, November 25-27, 2013, Proceedings</p

Логістична підтримка кіберспортивних проектів турнірного оператора

Робота публікується згідно наказу ректора від 21.01.2020 р. №008/од "Про перевірку кваліфікаційних робіт на академічний плагіат 2019-2020 р.р. навчальному році" . Керівник проекту: ст.викладач Воловик О.І.The modern globalized world is developing at a crazy pace. A great number of events are being held around the world at the same time. It influenced the rapid growth of the development of logistics for project and event management. Logistics plays a role of a bridge between virtual and physical reality and have also become an integral part of every project or event. To carry out a lot of events at the same time, it is required to establish a reliable logistical system, which can handle all the challenges posed. The events industry includes different types of events such as trade fairs, football matches, music festivals, or even newly arisen esports competitions. Esports is a modern time phenomenon, which becomes more and more popular. Esports events gather thousands of people under an umbrella of famous arenas and millions of viewers from all around the world who follow these events online. It is a growing world that brings people together from different states, continents, and origins with disregard of their nationality, religion, or background. Organizing and holding a big esports event is a very complicated task which is run by esports enthusiasts. The esports industry is faced with a certain lack of necessary knowledge, which in turn complicates the process of its development. The relevance of the topic is explained by the fact that esports events are attracting more and more attention, and for the successful implementation of their projects, esports tournament providers must operate with a strong logistics system through their logistical department or a third-party supplier. In this regard, the capabilities of logistics personnel must meet the growing requirements for organizing logistical support for large events. The study of the esports industry and project management tools make it possible to develop a well-prepared plan for the organization of logistical support for a big esports event, taking into account all the nuances of this industry. Production of quality esports events requires strong knowledge and significant experience. However, the acquisition of knowledge in esports complicated lack of wide research and accessible studies. Currently, certified academic institutions do not prepare staff for organizing and running esports events. The esports industry has a high entry barrier for new workers. Based on this, this bachelor thesis aims to justify preparation logistical support for esports events. The organization of logistical support of the project could be carried out by different project management tools, which have their advantages and disadvantages, as well as the area of application. So far esports has numerous titles that are divided by genres or platforms, and it will be reasonable to describe major parts of this industry and show the most successful examples of an esports event. In this paper, the organization of logistical support of The International - Dota 2 world championship will be considered. the budget of the logistical cost of the event will be calculated, and all the costs associated with transportation, accommodation, venue, etc., will be taken into account. Using special computer soft as Microsoft Office (Project, Excel, Visio) can simplify the process of implementation project management tools to the logistical support of the event.Сучасний глобалізований світ розвивається шаленими темпами. По всьому світу одночасно проводиться велика кількість заходів. Це вплинуло на швидке зростання розвитку логістики для управління проектами та заходами. Логістика відіграє роль мосту між віртуальною та фізичною реальністю, а також стала невід'ємною частиною кожного проекту чи події. Щоб проводити багато заходів одночасно, потрібно створити надійну логістичну систему, яка зможе впоратися з усіма поставленими проблемами. Індустрія подій включає різні типи подій, такі як ярмарки, футбольні матчі, музичні фестивалі або навіть нещодавно виниклі змагання з кіберспорту. Кіберспорт - це сучасний феномен часу, який стає все більш популярним. Кіберспортні заходи збирають тисячі людей під парасолькою відомих арен та мільйони глядачів з усього світу, які стежать за цими подіями в Інтернеті. Це світ, що зростає, що об’єднує людей з різних штатів, континентів та походження, нехтуючи своєю національністю, релігією чи походженням. Організація та проведення великого кіберспортивного заходу є дуже складною задачею, якою керують любителі кіберспорту. Індустрія кіберспорту стикається з певною відсутністю необхідних знань, що в свою чергу ускладнює процес її розвитку. Актуальність теми пояснюється тим, що еспортні заходи привертають дедалі більше уваги, і для успішної реалізації своїх проектів постачальники еспортних турнірів повинні працювати з потужною логістичною системою через свій відділ логістики або сторонніх постачальників. У зв'язку з цим можливості логістичного персоналу повинні відповідати зростаючим вимогам щодо організації матеріально-технічного забезпечення великих заходів. Вивчення індустрії кіберспорту та інструменти управління проектами дозволяють розробити добре підготовлений план організації матеріально-технічного забезпечення великого кіберспортивного заходу з урахуванням усіх нюансів цієї галузі. Виробництво якісних кіберспортивних заходів вимагає міцних знань та значного досвіду. Однак здобуття знань у кіберспорті ускладнило відсутність широких досліджень та доступних досліджень. В даний час сертифіковані академічні установи не готують персонал для організації та проведення кіберспортивних заходів. Індустрія кіберспорту має високий бар'єр для вступу нових працівників. Виходячи з цього, ця бакалаврська дипломна робота має на меті обґрунтувати підготовку матеріально-технічної підтримки до кіберспортивних заходів. Організація матеріально-технічного забезпечення проекту може здійснюватися за допомогою різних інструментів управління проектами, які мають свої переваги та недоліки, а також область застосування. На сьогоднішній день esports має безліч назв, розділених за жанрами або платформами, і розумно буде описати основні частини цієї галузі та показати найуспішніші приклади кіберспортивної події. У цій роботі буде розглянута організація матеріально-технічного забезпечення чемпіонату світу The International - Dota 2. буде розраховано бюджет матеріально-технічних витрат на захід, а також будуть враховані всі витрати, пов’язані з транспортом, проживанням, місцем проведення тощо. Використання спеціального комп’ютерного програмного забезпечення, як Microsoft Office (Project, Excel, Visio), може спростити процес впровадження інструментів управління проектами до матеріально-технічної підтримки заходу

A New Leader Election Algorithm based on the WBS Algorithm Dedicated to Smart-cities

International audienceOne of the interesting techniques for leader election is used in the WBS (Wait Before Starting) algorithm, in which each node in the network will wait for a time corresponding to its value before starting to send the first message to neighbours. This means that the node with the smallest value becomes the leader and it also starts first. This approach is impracticable in the case of real values (case of GPS-coordinates). Also, if the values are very large, the waiting time becomes too long. In this paper, we propose a fast, fault-tolerant and low energy leader election algorithm dedicated to smart-cities, which is based on the technique of waiting before starting, with minimum complexity and in which every node sends one and only one message. Here, the leader is the node with the smallest x-coordinate and the total of sent and received messages is used to represent the global consumption in the network. We give a detailed description of the algorithm, prove its accuracy, discuss its complexity in terms of exchanged messages and evaluate its performance using the CupCarbon simulator. We show that our algorithm is well balanced in terms of energy consumption, it is efficient and adapts well to the increase of the nodes number in the network

Rhythms of information infrastructure cultivation: the case of e-Mobility in Berlin

This thesis investigates the importance of temporal rhythms in the study of information infrastructures (IIs), responding to the call to address an II’s “biography” by focusing on its evolution over time. It enriches understanding of how socially constructed rhythms, a temporal structure under-examined in the II literature, influence II cultivation. A strategic niche project to develop an e-mobility II in Berlin is used as the case study and reveals the influence of rhythm in disciplining (constraining) and modeling (motivating) II cultivation. It demonstrates how the intermediary may mediate these influences through the interventions of harmonising, riffing and composing. Based on these interventions, the study develops the concept of facilitated II cultivation, which adds to the emergent literature exploring the tension between planned and emergent infrastructure work. In doing so, the study presents a framework that helps combine short-term implementation concerns (strategic interventions by the intermediary) with long-term path dependency and evolutionary concerns (influences of past and future temporal rhythms) for IIs