Blockchain e Sistemas de Reputação em Redes Veiculares: Uma Revisão Sistemática

Vehicular networks form an important pillar of current IntelligentTransportation Systems. Due to its specific characteristics, thesenetworks have been using reputation systems and or trust modelsto ensure security and trustworthiness. In addition, blockchainis a valuable technology that enables the development of thesesystems, addressing privacy, anonymity, and access control issues.This work aims to describe the results of the systematic literaturereviewon blockchain-based reputation systems.We compared someselected works and highlighted the adopted techniques and themain challenges

Asioiden Internetin tietoturva: ratkaisuja, standardeja ja avoimia ongelmia

Internet of Things (IoT) extends the Internet to our everyday objects, which enables new kind of applications and services. These IoT applications face demanding technical challenges: the number of ‘things’ or objects can be very large, they can be very con-strained devices, and may need to operate on challenging and dynamic environments. However, the architecture of today’s Internet is based on many legacy protocols and technology that were not originally designed to support features like mobility or the huge and growing number of objects the Internet consists of today. Similarly, many security features of today’s Internet are additional layers built to fill up flaws in the un-derlying design. Fulfilling new technical requirements set by IoT applications requires efficient solutions designed for the IoT use from the ground up. Moreover, the imple-mentation of this new IoT technology requires interoperability and integration with tra-ditional Internet. Due to considerable technical challenges, the security is an often over-looked aspect in the emerging new IoT technology. This thesis surveys general security requirements for the entire field of IoT applica-tions. Out of the large amount of potential applications, this thesis focuses on two major IoT application fields: wireless sensor networks and vehicular ad-hoc networks. The thesis introduces example scenarios and presents major security challenges related to these areas. The common standards related to the areas are examined in the security perspective. The thesis also examines research work beyond the area of standardization in an attempt to find solutions to unanswered security challenges. The thesis aims to give an introduction to the security challenges in the IoT world and review the state of the security research through these two major IoT areas

Protocolo adaptativo de disseminação de dados para aplicações de segurança no trânsito em rodovias

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Automação e Sistemas, Florianópolis, 2013.As VANETs (Vehicular Ad hoc Networks) são formadas por sistemas de comunicação entre veículos que fazem parte de um ambiente de trânsito e têm seus nós compostos por veículos e por equipamentos fixos que estão presentes ao longo das vias. Estas redes objetivam proporcionar conforto e segurança aos passageiros, por meio de informações sobre acidentes na pista, condição da estrada e aplicações de entretenimento. A disponibilidade e o tempo em que as mensagens trafegam nesta rede são essenciais para tais aplicações. Por isso, as VANETs requerem métodos eficientes e confiáveis para a comunicação de dados. Para prover confiabilidade à difusão de dados em redes veiculares deve-se transpassar alguns problemas como, por exemplo, broadcast storm, nós ocultos, alta colisões de pacotes, redundância de informação, entre outros. Muitos destes problemas persistem em estudos realizados anteriormente. Este trabalho tem por objetivo prover confiabilidade na disseminação de mensagens em aplicações voltadas a segurança no trânsito por meio de um protocolo adaptativo e eficiente. O protocolo proposto é adaptativo pois adapta o período entre transmissões de mensagens de controle de acordo com a densidade da rodovia, a fim de diminuir o número de mensagens geradas na rede. Também visa ser eficiente pois diminui a quantidade de colisões frente a quantidade de pacotes gerados na rede, oferece menor atraso no envio das mensagens e diminui a quantidade de retransmissões em cenários com mais de um alerta na rede. O trabalho envolveu (I) a definição do protocolo proposto, a integração e o uso deste pela aplicação, (II) a implementação de uma aplicação para rodovias com simuladores de redes e de tráfego bidirecionalmente acoplados, (III) avaliação da confiabilidade do protocolo proposto e dos impactos decorrentes do uso do protocolo na aplicação de disseminação de alertas por meio de simulações realizadas em diferentes cenários de densidade de veículos, e (IV) as análises dos resultados experimentais obtidos. Os resultados dos experimentos comprovam que o protocolo proposto, para os cenários simulados é 100 % confiável e que os impactos decorrentes do seu uso não prejudicam as funcionalidades da aplicação, comprovando a eficiência do protocolo.Abstract : The VANETs (Vehicular Ad hoc Networks) are formed by communication systems among vehicles which are part of the same traffic environment. Their nodes are composed of vehicles and fixed equipment present along the traffic ways. The aim of these networks is to provide comfort and safety to passengers through information about accidents on the road, road conditions and entertainment applications. The availability and the time span in which these messages move through the network are essential for these applications. Consequently, the VANETs require eficient and reliable methods for data communication. To ensure that data transmission in vehicular networks is reliable certain problems must be overcome, such as broadcast storm, hidden nodes, high collision of packages, information redundancy, among others. Many of these problems persist in previous studies. Thus, this work aims at providing, through an adaptive and eficient protocol, reliability to message transmission in applications targeted at traffic safety. The proposed protocol is adaptive as it adapts the time span between the transmissions of messages according to the road density, in order to decrease the number of messages generated in the network. It also aims at efficiency as it decreases the amount of collisions due to the number of packages generated in the network, presents less delay in message transmission and decreases the amount of retransmissions in scenarios with more than one alert in the network. This research involved (I) the definition of the proposed protocol, its integration and use by the application, (II) the implementation of an application for motorways with network and traffic simulators directionally attached, (III) evaluation of the reliability of the proposed protocol and of the impacts resulting from the use of the protocol in the application of spread of alerts through simulations carried out in diverse scenarios of vehicle density, (IV) the analyses of the experimental results. These results prove that the proposed protocol is 100 % reliable for simulated scenarios and that the impacts produced by its use do not harm the functionalities of the application, proving the eficiency of the protocol