Cette thèse étudie le choix optimal du système de retraite en Palestine. L'économie palestinienne se caractérise par un très faible niveau de protection sociale et un taux de pauvreté élevé .Le premier chapitre présente une analyse de l'environnement démographique, social et économique en Palestine. Le deuxième chapitre propose une revue de littérature sur les systèmes de protection sociale. Le troisième chapitre analyse le taux d'accès au système de protection sociale en fonction de différentes s caractéristiques socio-économiques. Le quatrième chapitre présente une analyse économétrique de la décision de participer au système de retraite. Le cinquième chapitre, en mobilisant le modèle PROST (Banque Mondiale), propose une analyse prospective du système de retraite en Palestine. L'étude prospective détermine le taux de cotisation approprié en fonction de plusieurs scénarios de chômage et son impact sur l'équilibre du système de retraite en prenant en compte la situation spécifique des femmes en Palestine. / This thesis aims to explore the optimal choice of retirement system for the Palestinian case motivated primarily by the problems of high poverty rate and the noticeably low coverage rate of social security.Accordingly, the first chapter focused on the environmental analysis of the Palestinian case. The second chapter focused on the literature review of social security. The third chapter explores the access rate to social security systems in each aspect of social security by socioeconomic characteristics. While, fourth chapter present an econometric analysis about the decision to participate at the pension system. Finally, chapter five presents and discusses guidelines for an optimal alternative pension reform followed by a projection test for proposed parameters of DB scheme using PROST model (World Bank) in several scenarios. The results determined the most important characteristics that increase the probability to participate to a pension system. Further, the projection shows the proper contribution rates in each unemployment scenario and its impact on the balance of the system and adequacy of income given the specific situation of females in Palestine.

The researcher attempts to establish how CCTV footage can be used as a surveillance technique, for evidence gained in that way to be admissible in court. To conduct effective investigation, it is important for investigators to be familiar with the application of CCTV footage, its purpose, its benefits and shortfalls. To achieve the goals and objectives of the practice of CCTV footage, investigators must know how to utilise the value of its evidence, and how to use it to identify suspects. The clarification and application to the crime situation, the identification of the perpetrator or suspect of a criminal act is mostly impossible, if CCTV footage is not available to assist in identification and tracing of suspects. / Police Practice / M. Tech. (Forensic Investigation)

A system is only as secure as the weakest link in the chain. Humans are the binding link between IT (information technology) security and physical secu-rity. In general, the human is often considered as the weakest link in the chain, so social engineering attacks are used to manipulate or trick people to accom-plish the goal of bypassing security systems. Within this master thesis, we answer several research questions related to social engineering. Most im-portant is to find out why humans are considered as the weakest link and why existing guidelines are failing, as well as to achieve the goal of raising aware-ness and starting education at a young age. For this, we examine existing lit-erature on the subject and create experiments, an interview, a campaign eval-uation, and a survey. Our systematic work begins with an introduction, the methodology, a definition of social engineering and explanations of state-of-the-art social engineering methods. The theoretical part of this thesis also in-cludes ethical and psychological aspects and an evaluation of existing guide-lines with a review of why they are not successful.Furthermore, we continue with the practical part. An interview with a profes-sional security consultant focusing on social engineering from our collabora-tion company TÜV TRUST IT GmbH (TÜV AUSTRIA Group)1 is con-ducted. A significant part here deals with awareness-raising overall, espe-cially at a younger age. Additionally, the countermeasures against each dif-ferent social engineering method are analysed. Another practical part is the evaluation of existing social engineering campaigns2 from TÜV TRUST IT GmbH TÜV AUSTRIA Group to see how dangerous and effective social en-gineering has been in the past. From experience gained in this thesis, guide-lines on dealing with social engineering are discussed before the thesis is fi-nalized with results, the conclusion and possible future work.

[pt] Uma estratégia comum de linha de produtos de software envolve sistemas da Web baseados em plug-ins que suportam a incorporação simples e rápida de comportamentos personalizados, sendo amplamente adotados para criar aplicativos baseados na web. A popularidade dos ecossistemas que suportam o desenvolvimento baseado em plug-ins (como o WordPress) é, em grande parte, devido ao número de opções de personalização disponíveis como plug-ins contribuídos pela comunidade. Entretanto, as vulnerabilidades relacionadas a plug-ins tendem a ser recorrentes, exploráveis e difíceis de serem detectadas e podem levar a graves conseqüências para o produto personalizado. Portanto, é necessário entender essas vulnerabilidades para permitir a prevenção de ameaças de segurança relevantes. Neste trabalho, realizamos um estudo exploratório para caracterizar vulnerabilidades causadas por plug-ins em sistemas baseados na web, examinando os boletins de vulnerabilidade do WordPress catalogados pelo National Vulnerability Database e os patches associados, mantidos pelo repositório de plugins do WordPress. Identificamos os principais tipos de vulnerabilidades, o seu impacto e o tamanho do patch para corrigir a vulnerabilidade. Identificamos, também, os tópicos mais comuns relacionados à segurança discutidos entre os desenvolvedores do WordPress. Observamos que, embora as vulnerabilidades possam ter consequências graves e permanecerem despercebidas por muito tempo, elas geralmente podem ser atenuadas com pequenas alterações no código-fonte. A caracterização ajuda a fornecer uma compreensão de como tais vulnerabilidades se manifestam na prática e contribui com as novas gerações de ferramentas de teste de vulnerabilidades capazes de antecipar sua possível ocorrência. Esta pesquisa propõe uma ferramenta de suporte para mitigar a ocorrência de vulnerabilidades em sistemas baseados em plugins web, facilitando a descoberta e antecipação da possível ocorrência de vulnerabilidades. / [en] A common software product line strategy involves plug-in-based web systems that support the simple and rapid incorporation of custom behaviors and are widely adopted for building web-based applications. The popularity of ecosystems that support plug-in-based development (such as WordPress) is largely due to the number of customization options available as community-contributed plugins. However, plug-in related vulnerabilities tend to be recurring, exploitable and difficult to detect and can lead to serious consequences for the custom product. Therefore, these vulnerabilities must be understood to enable the prevention of relevant security threats. In this paper, we conduct an exploratory study to characterize plug-in vulnerabilities in web-based systems by examining the WordPress vulnerability bulletins cataloged by the National Vulnerability Database and the associated patches maintained by the WordPress plugin repository. We identify the main types of vulnerabilities, their impact, and the size of the patch to address the vulnerability. We have also identified the most common securityrelated topics discussed among WordPress developers. We note that while vulnerabilities can have serious consequences and remain unnoticed for a long time, they can often be mitigated with minor changes to source code. Characterization helps provide an understanding of how such vulnerabilities manifest themselves in practice and contributes to new generations of vulnerability testing tools that can anticipate their potential occurrence. This research proposes a support tool to mitigate the occurrence of vulnerabilities in web plugin based systems, facilitating the discovery and anticipation of the possible occurrence of vulnerabilities.

Traditional solutions to information security in communication systems act in the application layer and are oblivious to the effects in the physical layer. Physical-layer security methods, of which information-theoretic security is a special case, try to extract security from the random effects in the physical layer. In information-theoretic security, there are two asymptotic notions of secrecy---weak and strong secrecy This dissertation investigates the problem of information-theoretic strong secrecy on the binary erasure wiretap channel (BEWC) with a specific focus on designing practical codes. The codes designed in this work are based on analysis and techniques from error-correcting codes. In particular, the dual codes of certain low-density parity-check (LDPC) codes are shown to achieve strong secrecy in a coset coding scheme. First, we analyze the asymptotic block-error rate of short-cycle-free LDPC codes when they are transmitted over a binary erasure channel (BEC) and decoded using the belief propagation (BP) decoder. Under certain conditions, we show that the asymptotic block-error rate falls according to an inverse square law in block length, which is shown to be a sufficient condition for the dual codes to achieve strong secrecy. Next, we construct large-girth LDPC codes using algorithms from graph theory and show that the asymptotic bit-error rate of these codes follow a sub-exponential decay as the block length increases, which is a sufficient condition for strong secrecy. The secrecy rates achieved by the duals of large-girth LDPC codes are shown to be an improvement over that of the duals of short-cycle-free LDPC codes.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-18T15:01:39Z No. of bitstreams: 1 MARCELL MANFRIN BARBACENA - DISSERTAÇÃO PPGCC 2014..pdf: 1468565 bytes, checksum: b94d20ffdace21ece654986ffd8fbb63 (MD5) / Made available in DSpace on 2018-04-18T15:01:39Z (GMT). No. of bitstreams: 1 MARCELL MANFRIN BARBACENA - DISSERTAÇÃO PPGCC 2014..pdf: 1468565 bytes, checksum: b94d20ffdace21ece654986ffd8fbb63 (MD5) Previous issue date: 2014 / Impulsionadas pela crescente demanda por sistemas de segurança para proteção do indivíduo e da propriedade nos dias atuais, várias pesquisas têm sido desenvolvidas com foco na implantação de sistemas de vigilância por vídeo com ampla cobertura. Um dos problemas de pesquisa em aberto nas áreas de visão computacional e redes de computadores envolvem a escalabilidade desses sistemas, principalmente devido ao aumento do número de câmeras transmitindo vídeos em tempo real para monitoramento e processamento. Neste contexto, o objetivo geral deste trabalho é avaliar o impacto que a redução da taxa de transmissão dos fluxos de vídeos impõe na eficácia dos algoritmos de detecção de pessoas utilizados em sistemas inteligentes de videovigilância. Foram realizados experimentos utilizando vídeos em alta resolução no contexto de vigilância com tomadas externas e com um algoritmo de detecção de pessoas baseado em histogramas de gradientes orientados, nos quais se coletou, como medida de eficácia do algoritmo, a métrica de área sob a curva de precisão e revocação para, em sequência, serem aplicados os testes estatísticos de Friedman e de comparações múltiplas com um controle na aferição das hipóteses levantadas. Os resultados obtidos indicaram que é possível uma redução da taxa de transmissão em mais de 70% sem que haja redução da eficácia do algoritmo de detecção de pessoas. / Motivated by the growing demand for security systems to protect persons and properties in the nowadays, several researches have been developed focusing on the deployment of widearea video coverage surveillance systems. One open research problem in the areas of computer vision and computer networks involves the scalability of these systems, mainly due to the increasing number of cameras transmitting real-time video for monitoring and processing. In this context, the aim of this study was to evaluate the impact that transmission data-rate reduction of video streams imposes on the effectiveness of people detection algorithms used in intelligent video surveillance systems. With a proposed experimental design, experiments were performed using high-resolution wide-area external coverage video surveillance and using an algorithm for people detection based on histograms of oriented gradients. As a measure of effectiveness of the people detection algorithm, the metric of area under the precision-recall curve was collected and statistical tests of Friedman and multiple comparisons with a control were applied to evaluate the hypotheses. The results indicated that it is possible to reduce transmission rate by more than 70% without decrease in the effectiveness of the people detection algorithm.

The scope of this work is analysing how economic policies chosen by governments are influenced by the power of social groups. The core idea is taken from the single-mindedness theory, which states that preferences of groups and their ability to focus on the consumption of goods enable them to obtain the most favourable policies. This approach exploits the advantages of probabilistic voting theory, ability to manage the multidiemnsionality and possibility to study precisely how politicians tailor their policies to groups' features. Unlike classic probabilistic voting models, my theory assumes that the density function which captures the distribution of political preferences depends on consumption of goods and preferences of individuals. The higher the consumption of goods, the higher the density, the higher the political power. This mechanism is better explained by considering the role played by "swing voters". Since they are pivotal to changing the equilibrium, candidates must favour them because they realise that even a small change in policy could force them to vote for the other candidate, Thus, the lower the loyalty of voters for parties, the higher the benefit they obtain. As a consequence, these voters are better off and represent the winners of the political process.

Made available in DSpace on 2014-12-17T14:56:05Z (GMT). No. of bitstreams: 1 MiriamVM.pdf: 955944 bytes, checksum: 0703348b1d68a5f32e8b6da9536de285 (MD5) Previous issue date: 2005-12-20 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Attacks to devices connected to networks are one of the main problems related to the confidentiality of sensitive data and the correct functioning of computer systems. In spite of the availability of tools and procedures that harden or prevent the occurrence of security incidents, network devices are successfully attacked using strategies applied in previous events. The lack of knowledge about scenarios in which these attacks occurred effectively contributes to the success of new attacks. The development of a tool that makes this kind of information available is, therefore, of great relevance. This work presents a support system to the management of corporate security for the storage, retrieval and help in constructing attack scenarios and related information. If an incident occurs in a corporation, an expert must access the system to store the specific attack scenario. This scenario, made available through controlled access, must be analyzed so that effective decisions or actions can be taken for similar cases. Besides the strategy used by the attacker, attack scenarios also exacerbate vulnerabilities in devices. The access to this kind of information contributes to an increased security level of a corporation's network devices and a decreased response time to occurring incidents / Ataques a dispositivos conectados em rede constituem um dos principais problemas relacionados ? confidencialidade das informa??es sens?veis e ao correto funcionamento dos sistemas de computa??o. Apesar da disponibilidade de ferramentas e de procedimentos que dificultam ou evitam a ocorr?ncia de incidentes de seguran?a, dispositivos de rede s?o atacados com sucesso utilizando-se estrat?gias aplicadas em eventos anteriores. O desconhecimento dos cen?rios nos quais esses ataques ocorreram contribui de maneira efetiva para o sucesso de novos ataques. O desenvolvimento de uma ferramenta que disponibilize esse tipo de informa??o ?, ent?o, de grande relev?ncia. Este trabalho apresenta um sistema de apoio ? gest?o de seguran?a corporativa para o armazenamento, a recupera??o e o aux?lio na composi??o de cen?rios de ataque e informa??es relacionadas. Se um incidente de seguran?a ocorrer em uma corpora??o, o especialista em seguran?a deve acessar o sistema para armazenar o cen?rio de ataque espec?fico. Este cen?rio, disponibilizado atrav?s de acesso controlado, deve ser estudado para que decis?es efetivas possam ser tomadas em casos semelhantes. Cen?rios de ataque evidenciam, al?m da estrat?gia utilizada pelo atacante, vulnerabilidades existentes em dispositivos. O acesso a este tipo de informa??o contribui para a eleva??o do n?vel de seguran?a dos dispositivos de rede de uma corpora??o e para a diminui??o do tempo de resposta ao incidente ocorrido

Orientador : Ricardo Dahab. / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Computação / Made available in DSpace on 2018-08-21T17:02:27Z (GMT). No. of bitstreams: 1 GalloFilho_RobertoAlves_D.pdf: 5999506 bytes, checksum: 6ef66e76246dddb7de30593abff60bc5 (MD5) Previous issue date: 2012 / Resumo A concepção de sistemas seguros demanda tratamento holístico, global. A razão é que a mera composição de componentes individualmente seguros não garante a segurança do conjunto resultante2. Enquanto isso, a complexidade dos sistemas de informação cresce vigorosamente, dentre outros, no que se diz respeito: i) ao número de componentes constituintes; ii) ao número de interações com outros sistemas; e iii) 'a diversidade de natureza dos componentes. Este crescimento constante da complexidade demanda um domínio de conhecimento ao mesmo tempo multidisciplinar e profundo, cada vez mais difícil de ser coordenado em uma única visão global, seja por um indivíduo, seja por uma equipe de desenvolvimento. Nesta tese propomos um framework para a concepção, desenvolvimento e deployment de sistemas baseados em hardware que é fundamentado em uma visão única e global de segurança. Tal visão cobre um espectro abrangente de requisitos, desde a integridade física dos dispositivos até a verificação, pelo usuário final, de que seu sistema está logicamente íntegro. Para alcançar este objetivo, apresentamos nesta tese o seguinte conjunto de componentes para o nosso framework: i) um conjunto de considerações para a construção de modelos de ataques que capturem a natureza particular dos adversários de sistemas seguros reais, principalmente daqueles baseados em hardware; ii) um arcabouço teórico com conceitos e definições importantes e úteis na construção de sistemas seguros baseados em hardware; iii) um conjunto de padrões (patterns) de componentes e arquiteturas de sistemas seguros baseados em hardware; iv) um modelo teórico, lógico-probabilístico, para avaliação do nível de segurança das arquiteturas e implementações; e v) a aplicação dos elementos do framework na implementação de sistemas de produção, com estudos de casos muito significativos3. Os resultados relacionados a estes componentes estão apresentados nesta tese na forma de coletânea de artigos. 2 Técnicas "greedy" não fornecem necessariamente os resultados ótimos. Mais, a presença de componentes seguros não é nem fundamental. 3 Em termos de impacto social, econômico ou estratégico / Abstract: The conception of secure systems requires a global, holistic, approach. The reason is that the mere composition of individually secure components does not necessarily imply in the security of the resulting system4. Meanwhile, the complexity of information systems has grown vigorously in several dimensions as: i) the number of components, ii) the number of interactions with other components, iii) the diversity in the nature of the components. This continuous growth of complexity requires from designers a deep and broad multidisciplinary knowledge, which is becoming increasingly difficult to be coordinated and attained either by individuals or even teams. In this thesis we propose a framework for the conception, development, and deployment of secure hardware-based systems that is rooted on a unified and global security vision. Such a vision encompasses a broad spectrum of requirements, from device physical integrity to the device logical integrity verification by humans. In order to attain this objective we present in this thesis the following set of components of our framework: i) a set of considerations for the development of threat models that captures the particular nature of adversaries of real secure systems based on hardware; ii) a set of theoretical concepts and definitions useful in the design of secure hardware-based systems; iii) a set of design patterns of components and architectures for secure systems; iv) a logical-probabilistic theoretical model for security evaluation of system architectures and implementations; and v) the application of the elements of our framework in production systems with highly relevant study cases. Our results related to these components are presented in this thesis as a series of papers which have been published or submitted for publication. 4Greedy techniques do not inevitably yield optimal results. More than that, the usage of secure components is not even required / Doutorado / Ciência da Computação / Doutor em Ciência da Computação

The aim of this diploma thesis is the analysis and comparison of labour taxation in the Czech Republic and Bulgaria. After the introduction, in which the goal and methods of solving are defined, there are two chapters that describe theoretically tax systems in both compared countries with focus on personal income tax and social security systems. The following chapter is devoted to indicators of effective taxation of labour, which are used for international comparisons. Another chapter will describe the comparison of the effective taxation of labour based on the achieved results. There is also an interval and global progressiveness that are used to measure the progressivity of the personal income tax in the Czech Republic and Bulgaria. In conclusion, there is a summary of the findings and aims of this thesis.