Approved for public release, distribution is unlimited / With the rapidly growing demand for portable devices such as laptops, handheld computers and Personal Digital Assistants (PDAs) with wireless networking capabilities, the need for reliable wireless data network communication has also increased. Just like in mobile voice communication, users demand uninterrupted, secure wireless data communication as they move from place to place. Mobile IP satisfies some of these demands - it enables mobile devices with fixed IP addresses to be permanently reachable even as their point of attachment to the network changes. This allows for routing of data packets to and from the mobile device irrespective of its location on the network. While uninterrupted data flow can be achieved with Mobile IP, it introduces additional security vulnerabilities, including data privacy, data integrity and authentication. The goal of this thesis is to investigate such vulnerabilities and explore implementations to overcome them. / Civilian, National Science Foundation

[pt] O crescimento da Internet, tanto do ponto de vista do número de usuários como dos serviços oferecidos, e o rápido progresso da tecnologia de comunicação sem fio, tornou possível uma demanda crescente por sistemas sem fios que permitam o acesso a Internet. Porém, um dos principais fatores desafiadores para o desenvolvimento desta nova forma de acesso é a mobilidade das estações móveis. A fim de resolver todos os problemas relacionados à introdução da mobilidade nesta nova forma de acesso, a Internet Engineering Task Force (IETF) através de pesquisas definiu o Mobile IP como o protocolo padrão para esse novo cenário. Embora este protocolo receba inúmeras contribuições que visam melhorar o seu desempenho tanto nas questões de handoff e de segurança dos registros dos usuários, este protocolo não recebe a mesma atenção para a questão da falha dos seus Agentes de Mobilidade. Estes agentes suportam as conexões das estações móveis integrando as redes sem fio com as redes IP amplamente difundida. Portanto, o objetivo desta dissertação é apresentar uma proposta de tolerância à falha dos Agentes de Mobilidade a fim de contribuir nesta linha de pesquisa. / [en] The growth of the Internet, as much of the point of view of the number of users as of the offered services, and the fast progress of the wireless communication technology, it became possible a demand for wireless systems that allow the access the Internet. However, one of the main challenging factors for the development this new access way is the mobility of the mobile stations. In order to solve all of the problems related to the introduction of the mobility in this new access form, the Internet Engineering Task Forces (IETF) through researches it defined Mobile IP as the standard protocol for that new scenery. Although this protocol receives countless contributions that seek to improve it so much acting in the handoff subjects and of safety of the users' registrations, this protocol doesn't receive the same attention for the subject of the fault of their Mobility Agents. These agents support the connections of the mobile stations integrating the wireless networks with IP netowrks spread. Therefore, the objective of this dissertation is to present a proposal of fault tolerance of the Mobility Agents in order to contribute in this research line.