[pt] As comunidades sociais online sao cada vez mais utilizadas como plataformas para diversas formas de interacao e compartilhamento de informacões, tanto em forma sincrona (em tempo real) quanto de forma assincrona. A perspectiva do acoplamento da computacao social com a capacidade atual de sensoriamento dos dispositivos moveis torna possível o desenvolvimento de aplicativos sociais com maior grau de sensibilidade ao contexto, de deteccao de atividades de individuos e grupos e também de uma interacao social implicita atraves do compartilhamento de informacoes de contexto. Alem do contexto pervasivo obtido a partir dos dispositivos moveis, os veinculos e interacoes do usuario nas redes sociais tambem podem ser considerados ricas fontes de informacao para aplicacoes pervasivas. O Mobile Social Gateway (MoSoGw) e um servico web que fornece uma interface generica para transferencia de informacao de uma forma otimizada entre os dispositivos moveis e diferentes redes sociais, bem como servicos de terceiros. Sua interface e generica na medida em que torna transparente para o aplicativo movel cliente a interacao com essas redes sociais e servicos de terceiros. O desempenho e a escalabilidade tambem foram levados em consideracao durante a concepcao e implementacao do MoSoGw. No contexto desta dissertacao, o termo escalabilidade deve ser entendido como a capacidade que a aplicacao tem de suportar um volume crescente de usuarios móveis ou estar preparada para esse crescimento. Assim, tanto a arquitetura quanto as tecnologias utilizadas em seu desenvolvimento foram cuidadosamente escolhidas de forma a escalar para milhares de clientes e suportar o alto volume de requisicoes simultaneas. / [en] Online social communities are increasingly used as platforms for manifold forms of interaction and information sharing, both in real-time and asynchronous. The prospect of coupling social computing with sensing capabilities of current mobile devices makes it possible to provide social applications with higher degrees of context-awareness, detection of activities of individuals and groups, as well as implicit social interaction through sharing of context-sensitive information. In addition to the pervasive context obtained from the mobile devices, the links and user interactions in social networks can be regarded as rich sources of information for pervasive applications. Mobile Social Gateway (MoSoGw) is a web service that provides a generic interface for optimized information transfer between mobile devices and different social networks, as well as third-party web services. Its interface is generic in that it makes transparent to the mobile client application the interaction with social networks and web services. Performance and scalability were major concerns when designing and implementing MoSoGw. Hence, its architecture and all technologies used in its development have been carefully chosen so as to scale to thousands of clients and support high volume of concurrent requests.

No sistema brasileiro de saúde, cabe aos Centros de Saúde o papel de órgão provedor de assistência médica primária. Para que esse papel seja cumprido com responsabilidade e eficácia, se mostrou fundamental a condução de programas públicos de atenção primária que envolvam visitas domiciliares aos pacientes. O objetivo desses programas, tais como o Estratégia de Saúde da Família (ESF), também conhecido como Programa de Saúde da Família (PSF), é o de melhorar a qualidade do serviço de saúde prestado à população por meio da aproximação entre equipes de saúde e a comunidade, permitindo, dessa forma, uma migração do paradigma de tratamento de doenças para o de promoção da saúde. No entanto, apesar da importância desses programas para a organização e articulação do sistema de atenção primária, as atividades de atenção domiciliar são normalmente conduzidas com pouco ou nenhum suporte de Tecnologia da Informação (TI). Esta pesquisa de mestrado tem por objetivo mostrar a definição e o desenvolvimento de um sistema móvel que auxilie os profissionais de saúde na coleta de informações dos pacientes que usufruem dos serviços de saúde citados acima. O projeto recebeu o nome de Projeto Borboleta e durante o tempo desta pesquisa várias versões do software foram desenvolvidas. Essas versões geraram protótipos do sistema que foram submetidos a testes em campo e, a partir da avaliação realizada pelos profissionais de saúde, surgiram alterações diversas. / In the Brazilian Health System, the healthcare centers have the role of primary health care providers. To successfully fulfill this responsibility with more dedication and effectiveness, the Brazil- ian government created public primary health programs of homecare where the health professionals visit the patient\'s homes. Those programs, as the Family Health Strategy (also known as Fam- ily Health Program), aim to raise the quality of health services provided by the centers to the neighboring community. This enables a new way of treatment of diseases and health care promo- tion. Nevertheless, those important programs have almost no Information Technology mechanisms helping them to manage the processes involved by the program. This master research objective is to present a definition and development of a mobile system that helps the healthcare providers to collect relevant data on the patient status on the site of the homecare treatment. The project was named as the Borboleta Project and during, the development of this research, several versions were released. Those versions were tested as prototypes on a real situation until a more stable version fitted the health professionals needs. Other objectives of this research were to analyze the solutions adopted by the development team, to describe the difficulties encountered by the team while working on this mobile system, and finally to show which were the feedbacks of the usage of the system on the field, during the test phase.

by Lau Wai Kwong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 99-102). / Abstract --- p.ii / Acknowledgements --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Limitations of the Mobile Computing Environments --- p.2 / Chapter 1.2 --- Applications of Transaction Replication in Mobile Environments --- p.5 / Chapter 1.3 --- Motivation for Transaction Replication in Mobile Environments --- p.5 / Chapter 1.4 --- Major Simulation Results --- p.6 / Chapter 1.5 --- Roadmap to the Thesis --- p.7 / Chapter 2 --- Previous and Related Research --- p.8 / Chapter 2.1 --- File Systems --- p.8 / Chapter 2.1.1 --- Management of Replicated Files --- p.8 / Chapter 2.1.2 --- Disconnected Operations --- p.10 / Chapter 2.2 --- Database Management --- p.12 / Chapter 2.2.1 --- Data Replication Schemes --- p.12 / Chapter 2.2.2 --- Cache Invalidation and Query Processing --- p.15 / Chapter 2.2.3 --- Transaction Management in Mobile Environments --- p.17 / Chapter 3 --- System Model and Assumptions --- p.21 / Chapter 3.1 --- System Architecture --- p.21 / Chapter 3.2 --- Transaction and Data Model --- p.23 / Chapter 3.3 --- One-copy Serializability --- p.25 / Chapter 3.4 --- Assumptions --- p.27 / Chapter 4 --- Transaction Replication in a Mobile Environment --- p.29 / Chapter 4.1 --- Read-only Public Transactions --- p.30 / Chapter 4.1.1 --- Data Broadcasting --- p.31 / Chapter 4.1.2 --- Cache Update --- p.33 / Chapter 4.1.3 --- Cache Miss --- p.36 / Chapter 4.1.4 --- Execution of Read-only Public Transactions --- p.37 / Chapter 4.2 --- R/W Public Transactions --- p.39 / Chapter 4.3 --- Correctness Argument --- p.41 / Chapter 4.3.1 --- Correctness Proof --- p.43 / Chapter 4.4 --- Extension to Support Partition Failures --- p.47 / Chapter 5 --- Design and Implementation of the Simulation --- p.49 / Chapter 5.1 --- CSIM Language --- p.49 / Chapter 5.2 --- Simulation Components --- p.50 / Chapter 5.2.1 --- Fixed Network --- p.50 / Chapter 5.2.2 --- Mobile Host --- p.50 / Chapter 5.2.3 --- Wireless Channel --- p.51 / Chapter 5.2.4 --- Database and Transactions --- p.52 / Chapter 5.3 --- A Lock-based Scheme --- p.53 / Chapter 5.4 --- Graphing ...........、 --- p.54 / Chapter 6 --- Results and Analysis --- p.55 / Chapter 6.1 --- Results Dissection --- p.55 / Chapter 6.2 --- Performance of the Scheme --- p.56 / Chapter 6.2.1 --- Parameters Setting --- p.56 / Chapter 6.2.2 --- Experiments and Results --- p.59 / Chapter 6.3 --- Comparison with the Lock-based Scheme --- p.78 / Chapter 6.3.1 --- Parameters Setting --- p.79 / Chapter 6.3.2 --- Experiments and Results --- p.80 / Chapter 7 --- Conclusions and Future Work --- p.93 / Chapter 7.1 --- Conclusions --- p.93 / Chapter 7.2 --- Future Work --- p.94 / Chapter A --- Implementation Details --- p.96 / Bibliography --- p.99

The need for information anywhere and at any time has been the driving force for the increasing growth in mobile networks and devices. The field of mobile computing is the merger of advances in computing and communications with the aim of providing seamless and ubiquitous computing environment for mobile users. Whereas notebook computers and personal digital assistants (PDAs) are self-contained, networked computing constitutes a new paradigm of computing that is revolutionizing the way computers are used. Mobile networking greatly enhances the utility of carrying a computing device. It provides mobile users with versatile communication to other people and expedient notification of important events, yet with much more flexibility than cellular telephones and pagers. It also permits continuous access to services and resources of the traditional land-based wired networks. This combination of networking and mobility will engender new applications and services, such as collaborative software to support impromptu meetings, electronic bulletin boards that adapt to the contents according to the participants present, self adjusting lighting and heating, and navigation software to guide users in unfamiliar places and tours. To support mobility in the Internet, the Internet Protocol (IP) has been extended to support mobility. Also at the same time, there is also a growing trend for these IP based networks to operate in an infrastructureless environment called mobile ad-hoc networks. However, the proliferation of such mobile networks depends on a multitude of factors, with trustworthiness being one of the primary challenges to be met. The objective of this dissertation is to address the issues involved in the design of security services for Mobile IP and ad-hoc networks. Extensions to IP based networks (both wired and infrastructureless networks) to facilitate mobility have not been designed keeping security in mind. However adequate security features are basic requirements for the continued functioning of mobile networks. Clearly the problem is so broad that there is no way to devise a general solution We aim to address most of these wide- ranging problems and in the process initiate a practical approach to the development of an integrated security infrastructure for mobile networks. The intention is to seamlessly integrate these security services and mechanisms at the IP level within the mobile IP and ad-hoc networks. The provision of security services at the higher and lower layers and their interoperability with our proposed framework is outside the scope of this thesis / Doctor of Philosophy (PhD)

Thesis (M.S.)--University of Nevada, Reno, 2005. / "December 2005." Includes bibliographical references (leaves 49-55). Online version available on the World Wide Web.

Thesis (Doctoral)--Universität des Saarlandes, 2006. / Includes bibliographical references (p. 175-193) and index.

Security engineering is one of the important concerns during system development. It should be addressed throughout the whole system development process; however in many cases it is often dealt only during system development and maintenance. There are several security modeling languages (e.g, Misuse case, Secure Tropos) that help dealing with security risk management at the requirements stage. In this thesis, we are focusing on the modeling languages (e.g. Mal activity diagrams and SecureUML) that are used to design the system. More specifically we investigate how these languages support information systems security risks management (ISSRM). The outcome of this work is an alignment table between the Mal activity diagrams and SecureUML language constructs to the ISSRM domain model concepts. We ground our analysis and validate the received results on the number of illustrative examples. We hope that our results will help developers to understand how they can consider security risks at the system design stage. In addition we open the way for the interoperability between different modeling languages that are analysed using the same conceptual background, thus, potentially leading to the transformation between these modeling approaches.

GSM network capable of connecting to any operator providing SIP trunk has beenconstructed to serve as a target for controlled experiment on DoS attacks againstGSM. The usage of this network as a tool to perform DoS attack against mobilephones was also investigated and documented.Open source implementation of testing tool to check DoS resilience of any GSMbase station against RACH flood attack was developed as part of this thesis.Additionally, the analysis of the GSM flaws which opened the possibility for DoSattacks, and the analysis of potential countermeasures is presented.

Typical authentication systems provide a method to allow registered users access to protected resources after the user successfully authenticates. A user successfully authenticates by proving his or her valid identity if he or she is a registered user. During a typical authentication process, the authentication server can directly or indirectly learn the actual identity of the user who authenticates. However, the user might not want any one to know the actual identity of the user, while still able to authenticate. This problem of user's anonymous authentication is the focus of this thesis project. This thesis project provides a solution for user's anonymous authentication using Secure Multi-party Computation (SMPC). In SMPC, the user information is distributed among the authentication servers, using a secret sharing scheme, in such a way that none of the authentication server individually possesses all the information of a user. However, these authentication servers can validate the user using some SMPC arithmetic operations. This thesis project provides a model for anonymous authentication and couples this anonymous authentication system with the Open Authentication Protocol (OAuth) to allow the user access to protected resources on the server. The model is explained using UML collaborations and SDL state transition diagrams. A analysis of the model is provided to ensure the security of the proposed system. A skeleton of the proposed model is provided which needs to be completed with appropriate code to realize the functionalities. This thesis project also provides an implementation of a simplified prototype which represents the core of the proposed model for anonymous authentication.

Cloud Computing is a new computing model, and its security aspects require special considerations. New characteristics of the cloud model have introduced new security challenges, and made some of the existing security techniques incompatible. Moreover, existing cloud environments are closed, operated by commercial providers, and their security mechanisms are proprietary as well as confidential. In other words, there is not much chance of observing how a real cloud environment is working, and how their providers adapt security measures to the new model.Therefore, we have chosen an open source cloud platform to build our own cloud environment. The OpenStack cloud software met our requirements, but it was not mature enough. We have done a deep analysis of this platform, identified potential attack targets in it, and discuss impacts of a successful attack.In order to secure our environment, the National Institute of Standards and Technology (NIST) incident handling guideline has been applied to the cloud model, and corresponding actions for each phase has been performed. To complete our study, we have proposed a set of cloud specific approaches that fulfill the incident handling requirements. These approaches address challenges identified in the guideline adaptation process. Additionally, we have studied the feasibility and compatibility of each approach against our deployed environment.Additionally, we also have submitted a paper to IEEE CloudCom 2011 conference, based on my thesis. A draft version of the paper is included in Appendix A.