The surge of mobile devices, such as smartphones, and tables, demands additional capacity. On the other hand, Internet-of-Things (IoT) and smart grid, which connects numerous sensors, devices, and machines require ubiquitous connectivity and data security. Additionally, some use cases, such as automated manufacturing process, automated transportation, and smart grid, require latency as low as 1 ms, and reliability as high as 99.99\%. To enhance throughput and support massive connectivity, sharing of the unlicensed spectrum (3.5 GHz, 5GHz, and mmWave) is a potential solution. On the other hand, to address the latency, drastic changes in the network architecture is required. The fifth generation (5G) cellular networks will embrace the spectrum sharing and network architecture modifications to address the throughput enhancement, massive connectivity, and low latency. To utilize the unlicensed spectrum, we propose a fixed duty cycle based coexistence of LTE and WiFi, in which the duty cycle of LTE transmission can be adjusted based on the amount of data. In the second approach, a multi-arm bandit learning based coexistence of LTE and WiFi has been developed. The duty cycle of transmission and downlink power are adapted through the exploration and exploitation. This approach improves the aggregated capacity by 33\%, along with cell edge and energy efficiency enhancement. We also investigate the performance of LTE and ZigBee coexistence using smart grid as a scenario. In case of low latency, we summarize the existing works into three domains in the context of 5G networks: core, radio and caching networks. Along with this, fundamental constraints for achieving low latency are identified followed by a general overview of exemplary 5G networks. Besides that, a loop-free, low latency and local-decision based routing protocol is derived in the context of smart grid. This approach ensures low latency and reliable data communication for stationary devices. To address data security in wireless communication, we introduce a geo-location based data encryption, along with node authentication by k-nearest neighbor algorithm. In the second approach, node authentication by the support vector machine, along with public-private key management, is proposed. Both approaches ensure data security without increasing the packet overhead compared to the existing approaches.

With advances in information technology, various cloud computing related research and development has become a hot trend. Except the vast amount of studies and reports appearing in local magazines and newspapers, government agencies have also set up corresponding R & D projects. However, most of these studies focus on the infrastructure or platform level of the cloud. For example, the projects for Infrastructure as a Service (IaaS) include the Cloud Computing Center for Mobile Application at Industrial Technology Research Institute (ITRI), the Cloud Service and Technology Center at Information Industry Institute (III) and the already launched ¡§hiCloud¡¨ at Chunghwa Telecom Corporation. In the business side, there is TCloud Computing that does the development of both "Infrastructure" and "Platform as a Service" (PaaS). As to Software as a Service (SaaS) related research, III has gathered 10 domestic companies to participate the co-operation plans for education cloud, manufacture cloud, ¡K and practice cloud, a total of nine cloud services. However, they are all in the early stages without much success stories or usages. The study of this thesis is angled toward business needs, from the point of resource-based analysis to see how a firm will be affected if introduction of SaaS to business. In particular, we will study this subject from four dimensions, which are the competitiveness of enterprises, IT outsourcing strategy, cost structure analysis and data security technology, to identify the possible critical factors for the introduction for cloud computing services. As most people are perceived, cloud computing has a comparative advantage of cost saving over traditional approach.

O crescimento e proliferação da Internet nos últimos anos tem trazido à tona vários problemas relativos à segurança e operacionabilidade das máquinas de universidades e empresas. Inúmeras invasões são realizadas anualmente. Entretanto, a grande maioria delas não possui registro algum, sendo muitas vezes de total desconhecimento do administrador local. Para prover soluções para estes problemas foi realizado um estudo, aqui apresentado, que tem como principal objetivo propor uma filosofia de gerência de segurança. São utilizados para isso conceitos de gerenciamento de redes como SNMPv2, aliado à implementação de um conjunto de ferramentas que garantam a integridade dos vários sistemas envolvidos. O resultado foi um sistema denominado CUCO1, que alerta sobre tentativas de ataque e situações de risco. CUCO foi projetado para permitir a um administrador, protegido ou não por uma firewall, dispor de um controle maior e melhor sobre acessos e tentativas de acessos indevidos à sua rede. O sistema usa uma estratégia de monitoração de eventos em diferentes níveis e aplicações, tentando com isto detectar e alertar a ocorrência de ataques tradicionais. Também está incorporado um bloco de funções que visam identificar um agressor situado em algum lugar da Internet, e obter maiores informações sobre ele e o domínio onde esta localizado. / The Internet increase and proliferation in the last years has brought a lot of problems related to the security and handling of hosts in universities and corporations. Many break-ins are done each year, without any record or knowledge by the site’s administrator. To give solutions to this problems was made up a study, here presented, has as the main goal the proposal of a security management philosophy. Are used network management concepts, joined with a toolkit to ensure the integrity of many systems envolved. The result was a system named CUCO2, that alerts about attacks and risks situations. CUCO was designed to allow an administrator, protected or not by firewall, to have a bigger and better access control in his network. The system uses an event monitor strategy in different levels and applications, trying to detect and alert the occurrence of common attacks. Moreover, it is also incorporated by a set of functions that attempt to identify aggressor’s location in any place in the Internet, and get information about him and the domain where he is located.

Orientador: Prof. Dr. João Henrique Kleinschmidt / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2015. / Na Internet das Coisas os objetos físicos têm um componente virtual capaz de prover ou requisitar determinados serviços. É uma tendência que trará vantagens sem precedentes para a automação de processos e diversas aplicações. A análise de modelos de gerenciamento de confiança para IoT para detectar comportamentos maliciosos tem recebido poucas contribuições da comunidade científica. Alguns pesquisadores trataram desta questão, mas poucos trabalhos analisam os requisitos para a correta implementação da IoT. O objetivo desta dissertação é identificar o comportamento malicioso de nós e prevenir possíveis ataques que interrompam os serviços da rede. Neste trabalho são feitas diferentes abordagens para pesquisar um modelo de gerenciamento de confiança capaz de caracterizar o comportamento dos nós. O modelo proposto usa informações diretas geradas pelas comunicações entre os nós e recomendações de outros nós para calcular a confiança. Usa uma abordagem multi-serviço em que cada nó provê diversos serviços para os outros nós da rede. A habilidade de um nó em prover um serviço é recompensada, enquanto que um nó que não forneça um serviço corretamente é punido. Cada nó tem uma tabela de confiança dos seus vizinhos, que pode ser compartilhada com os outros nós como recomendações. A abordagem distribuída permite que os nós sejam completamente autônomos em tomar decisões sobre o comportamento dos nós. A avaliação de confiança dos nós é um meio efetivo de encorajar a colaboração na rede e ao mesmo tempo melhorar a segurança em redes distribuídas. Três ataques são testados para verificar a validade do modelo de confiança: ataque On-Off, ataque Seletivo e Bad mouthing. O modelo de gerenciamento de confiança foi implementado no Contiki, um sistema operacional desenvolvido para IoT e redes de sensores. Extensivas simulações foram feitas no simulador Cooja-Contiki para ilustrar os ataques e avaliar o desempenho do modelo proposto. Os resultados de simulação mostram que o modelo tem um bom desempenho em detectar os nós maliciosos. / In Internet of Things (IoT), the physical objects have a virtual component able to provide or require determined services. It is a trend that will bring unprecedented advantages to the process automation. The analysis of the trust management models for IoT to detect the malicious behavior on the network, has been undervalued and with little scientific contribution in the academic field. In spite of researchers has already addressed the issue, only few give a theoretic analysis on the requirements for the proper implementation of IoT. The purpose of this thesis work is to identify the malicious behavior of the nodes and prevent possible attacks that disrupt entire network to IoT context. In this thesis different approaches are followed to investigate a lightweight model of trust management able to characterize the behavior of the nodes with little effort. Our model use direct information generated from direct communication of nodes and recommendations of the others nodes to evaluate the trust. We use a multi-service approach where each node provides several services to others node. The ability to provide a service is rewarded and, punished when it is not provided. In our trust model each node has a trust table of their neighbors in the same radio coverage, which will be shared to others nodes as recommendations. This distributed approach allows nodes to be completely autonomous in making decisions about the behavior of other nodes. The trust evaluation of nodes is an effective method to encourage the collaboration on the network and at the same time to improve network security in distributed networks. In this thesis work, we present three attacks that can undermine the accuracy of trust evaluation. Based on our investigation on attacks and defense, we designed and implemented a trust management model based on the construction of Contiki, an operating system developed for IoT and sensor networks. Extensive simulations were performed using COOJA-Contiki to illustrate On-OFF attack, Selective attack and Bad mouthing attack, the effectiveness of the techniques used, and the overall performance of the proposed trust model. Simulation results shows effectiveness against these attacks and also a good performance to recognize the malicious nodes especially to the Bad mouthing attack when are used direct information and recommendations wherein is obtained a reduction time compared when is used only the direct information.

Information security is being considered of great importance to the private and governamental institutions. For this reason, we opted to conduct a study of security in this dissertation. We started with an introduction to the information theory, and then we proposed a new kind of Perfect Secrecy cryptographic and finally made a study of steganography in an image sequence, in which we suggest a more aggressive steganography in coefficients of the discrete cosine transform. / A segurança da informação vem sendo considerada de grande importância para as instituições privadas e governamentais. Por este motivo, optamos em realizar um estudo sobre segurança nesta dissertação. Iniciamos com uma introdução à teoria da informação, partimos para métodos de criptografia onde propomos um novo tipo de Segredo Perfeito e finalmente fazemos um estudo de esteganografia em uma sequência de imagens, onde propomos uma esteganografia mais agressiva nos coeficientes da transformada discreta de cosseno.

O crescimento e proliferação da Internet nos últimos anos tem trazido à tona vários problemas relativos à segurança e operacionabilidade das máquinas de universidades e empresas. Inúmeras invasões são realizadas anualmente. Entretanto, a grande maioria delas não possui registro algum, sendo muitas vezes de total desconhecimento do administrador local. Para prover soluções para estes problemas foi realizado um estudo, aqui apresentado, que tem como principal objetivo propor uma filosofia de gerência de segurança. São utilizados para isso conceitos de gerenciamento de redes como SNMPv2, aliado à implementação de um conjunto de ferramentas que garantam a integridade dos vários sistemas envolvidos. O resultado foi um sistema denominado CUCO1, que alerta sobre tentativas de ataque e situações de risco. CUCO foi projetado para permitir a um administrador, protegido ou não por uma firewall, dispor de um controle maior e melhor sobre acessos e tentativas de acessos indevidos à sua rede. O sistema usa uma estratégia de monitoração de eventos em diferentes níveis e aplicações, tentando com isto detectar e alertar a ocorrência de ataques tradicionais. Também está incorporado um bloco de funções que visam identificar um agressor situado em algum lugar da Internet, e obter maiores informações sobre ele e o domínio onde esta localizado. / The Internet increase and proliferation in the last years has brought a lot of problems related to the security and handling of hosts in universities and corporations. Many break-ins are done each year, without any record or knowledge by the site’s administrator. To give solutions to this problems was made up a study, here presented, has as the main goal the proposal of a security management philosophy. Are used network management concepts, joined with a toolkit to ensure the integrity of many systems envolved. The result was a system named CUCO2, that alerts about attacks and risks situations. CUCO was designed to allow an administrator, protected or not by firewall, to have a bigger and better access control in his network. The system uses an event monitor strategy in different levels and applications, trying to detect and alert the occurrence of common attacks. Moreover, it is also incorporated by a set of functions that attempt to identify aggressor’s location in any place in the Internet, and get information about him and the domain where he is located.

O crescimento e proliferação da Internet nos últimos anos tem trazido à tona vários problemas relativos à segurança e operacionabilidade das máquinas de universidades e empresas. Inúmeras invasões são realizadas anualmente. Entretanto, a grande maioria delas não possui registro algum, sendo muitas vezes de total desconhecimento do administrador local. Para prover soluções para estes problemas foi realizado um estudo, aqui apresentado, que tem como principal objetivo propor uma filosofia de gerência de segurança. São utilizados para isso conceitos de gerenciamento de redes como SNMPv2, aliado à implementação de um conjunto de ferramentas que garantam a integridade dos vários sistemas envolvidos. O resultado foi um sistema denominado CUCO1, que alerta sobre tentativas de ataque e situações de risco. CUCO foi projetado para permitir a um administrador, protegido ou não por uma firewall, dispor de um controle maior e melhor sobre acessos e tentativas de acessos indevidos à sua rede. O sistema usa uma estratégia de monitoração de eventos em diferentes níveis e aplicações, tentando com isto detectar e alertar a ocorrência de ataques tradicionais. Também está incorporado um bloco de funções que visam identificar um agressor situado em algum lugar da Internet, e obter maiores informações sobre ele e o domínio onde esta localizado. / The Internet increase and proliferation in the last years has brought a lot of problems related to the security and handling of hosts in universities and corporations. Many break-ins are done each year, without any record or knowledge by the site’s administrator. To give solutions to this problems was made up a study, here presented, has as the main goal the proposal of a security management philosophy. Are used network management concepts, joined with a toolkit to ensure the integrity of many systems envolved. The result was a system named CUCO2, that alerts about attacks and risks situations. CUCO was designed to allow an administrator, protected or not by firewall, to have a bigger and better access control in his network. The system uses an event monitor strategy in different levels and applications, trying to detect and alert the occurrence of common attacks. Moreover, it is also incorporated by a set of functions that attempt to identify aggressor’s location in any place in the Internet, and get information about him and the domain where he is located.

Detta examensarbete kommer att behandla hur man kan skapa en webbplats med tillhörande spel med hjälp av PHP-ramverket CodeIgniter. Rapporten tar upp hur detta ramverk fungerar och hur applikationer i ramverket kan göras säkra. Läsaren kommer att få veta mer om vilka HTML-standarder man kan använda för webbplatser och om den programmeringsmetod, MVC-principen, som CodeIgniter använder sig av. Kortfattat tar rapporten upp teknisk webbutveckling och programmeringen bakom densamma. / This thesis will examine how to create a web site with a game, based on the PHP-framework CodeIgniter. The report explains how this framework works and how you can make secure applications by using the framework. The reader will also get to know more about the HTML-standards possible to use for web sites and about the programming method, the MVC-principle, CodeIgniter is using. In short, the report explains technical web development and the programming behind it. / Kontakt med författaren kan ske via dennes webbplats, http://www.bjornlarsson.se/.Detta verk är licensierat under en Creative Commons Erkännande-IckeKommersiell 2.5 Sverige Licens (http://creativecommons.org/licenses/by-nc/2.5/se/).

The main subject of this thesis is the security of Android platform mobile devices. The goal of the thesis is to design and develop an application that will check given devices from the security point of view and to check the security of applications developed as the subject of theses created in the last few years at the University of Economics. In the first part of thesis there is an analysis of ways to secure the Android platform devices and applications and ways to attack them. Both the offline and the client/server architecture applications are also taken into consideration. The next part includes a security analysis of the selected application based on the beforehand determined criteria. An analysis and development of the application designated to examine the security of the given device is next. The outcome of the thesis is an easy to use application that can be launched on the mobile devices running Android 2.2 Froyo and higher.

The goal of this doctoral thesis is to analyse some legal, technical and economic aspects, related to the development of e-Government in the Czech Republic and to draw some general prerequisites for a successful development of e-Government services. The work contains a review of the legislation, which has a direct or indirect impact on the development of e-Government. It concerns mainly the digital signature legislation, public administration information systems, general regulations on administrative procedures and some special regulations. In this thesis there are analysed in detail currently implemented e-Government projects, especially the public administration contact points, the data inboxes, the authorized documents' conversion and the basic registers of public administration. Special attention is also devoted to the questions of personal data security in information systems. Possible effects of e-Government are evaluated with regard to recipients of public administration, particularly to citizens and legal persons. Measurable indicators (metrics) are proposed to measure the progress of individual e-Government projects, along with the procedure of their calculation. This thesis concludes that for reliable measurement of efficiency, it is necessary to identify some quantifiable indicators on the cost side as well as and on the benefits side. These indicators should be oriented to the cost aspect as well as to the specific objectives of public administration. As for the methodology, in the thesis there are used the usual methods of research in the field of legal science. Concretely used methods are the process analysis, cost analysis and metrics analysis, whose methodology is based primarily on the economics, management and information management. Furthermore, the case studies have been used to fulfil the objectives of the thesis and to verify the thesis' hypotheses.