Wireless communication has played a very important role in people communication activities due to the properties of fast mobility and high portability. Many security mechanisms for mobile communications have been introduced in the literature. Among these mechanisms, authentication is a quite important task in the entire mobile network system and acts as the first defense against attackers since it ensures the correctness of the identities of distributed communication entities before they engage in any other communication activity. Some schemes have similar drawbacks, such as high bandwidth consumption between VLR and HLR, storage overhead in VLR, and lack of VLR authentication. On the other hand, some protocols are efficient, but they are not based on rational assumptions. Ideally, a mobile authentication scheme should achieve mutual entity authentication, low storage cost in VLR, and light-weight computation and communication for each entity, to provide secure and fast communication services. Therefore, in order to guarantee the quality of this advanced technology, an efficient (especially, user efficient) and secure authentication scheme is urgently desired, and moreover, it should be under reasonable assumptions. In this dissertation, we come up with a novel authentication mechanism, called the nested one-time secret mechanism, tailored for mobile communication environments. Through maintaining inner and outer synchronously changeable common secrets, respectively, every mobile user can be rapidly authenticated by VLR and HLR, respectively, in the proposed scheme based on rational assumptions. Not only does the proposed solution achieve mutual authentication, but also it greatly reduces the computation and communication cost of the mobile users as compared with the existing authentication schemes. Finally, we formally prove that the proposed scheme is a secure mutual authentication and key exchange scheme under the assumptions of semantic security of encryption, indistinguishability of a pseudorandom function and a random function, and indistinguishability of a pseudorandom permutation and a random permutation.

published_or_final_version / Public Administration / Master / Master of Public Administration

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Thesis (M.P.A.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 101-107).

Thesis (M.P.A.)--University of Hong Kong, 1996. / Includes bibliographical references (leaves 101-107). Also available in print.

Colorectal cancer (CRC) is the second leading cancer killer in the United States and the third most common cancer in African American men and women. Though the overall death rates have declined, this reduction in mortality is smaller for African Americans than for Whites. Factors that are protective against colorectal cancer include occupational or recreational physical activity, a diet high in fruits and vegetables, and colorectal cancer screening with removal of polyps (polypectomy) before they progress to cancer. Compliance with CRC screening recommendations requires people to know if a first-degree relative (parent, sibling, and child) or second-degree relative (aunt, uncle, niece, nephew, and grandparent) has been diagnosed with colorectal cancer. Little is known about how patients disclose this information to their relatives and what type of information is disclosed when disclosure takes place. The role of the family has long been overlooked in research on African American health screening behavior despite the fact that family interventions have been known to produce favorable outcomes in diet, nutrition, and exercise. This qualitative study explored the disclosure process among African American colorectal cancer survivors and FDRs with whom they shared their diagnosis. Of special interest was the role of social support in the disclosure process and the criteria used to decide which relatives to tell. Findings from this study will be used to advance the knowledge about the dynamics of CRC disclosure to first-degree relatives in African American families and ultimately increase CRC screening in relatives.

[pt] Esta pesquisa tem como objetivo avaliar as consequências, para a dinâmica familiar, da revelação de abuso sexual intrafamiliar de crianças, em particular no que se refere a sua organização e a seus processos de estabelecimento, manutenção, modificação e rompimento de relações, vínculos e alianças. Sugere, desta forma, uma discussão sobre o abuso sexual intrafamiliar de crianças como síndrome de segredo e adição e como uma forma de manutenção da coesão do grupo familiar, com precipitação de uma crise a partir da ruptura do segredo e deflagração de uma série de intervenções dos integrantes do Sistema de Garantia de Direitos de Crianças e Adolescentes (SGD). Para viabilizar a análise das vicissitudes experimentadas pelas famílias, procedeu-se a um estudo qualitativo que, utilizando a técnica da entrevista narrativa, possibilitou o acesso ao discurso familiar enunciado a partir da fala de 03 (três) mães, cujas famílias foram acompanhadas por um Centro de Referência Especializado de Assistência Social (CREAS) do município do Rio de Janeiro no processo de proteção e responsabilização e de reorganização familiar. As entrevistas foram gravadas com a permissão das informantes, transcritas e submetidas à análise de conteúdo na sua modalidade temática. As conclusões apontam para a necessidade de abordagens que compreendam a família como totalidade, incluídos seus vínculos e elementos de coesão, construtivos ou destrutivos, como forma de escapar aos limites impostos por intervenções centradas na díade autor–vítima e de contribuir para o processo de reorganização familiar. / [en] This research aims to evaluate the consequences of the disclosure of intrafamilial sexual abuse of children for the family dynamics, particularly in regard to its organization and its processes of establishment, maintenance, modification and disruption of relationships, linkages and alliances. Thus, it suggests a discussion of intrafamilial sexual abuse of children as a secrecy and addiction syndrome and as a way of maintaining cohesion of the family group, unleashing a crisis as of the disclosure of the secrecy and the resulting series of interventions by the members of the Warranty System of Children’s Rights (SGD). To facilitate the analysis of the vicissitudes experienced by the families, we proceeded to a qualitative study, by means of the narrative interview technique, which provided access to the testimony of 3 (three) mothers whose families were accompanied by a Social Assistance Specialized Reference Center (CREAS) in the municipality of Rio de Janeiro as part of the process of accountability and protection and family reorganization. The interviews were recorded with the permission of the informants, transcribed and submitted to content analysis in their thematic modality. The results point to the need for approaches to understand the family as a whole, including its links and elements of cohesion, either constructive or destructive, as a way to escape the limits imposed by interventions focused on the perpetrator-victim dyad as well as contribute to the family reorganization process.

Tumbleweed Road is a novel that began as a short story in a fiction workshop many years ago. The novel is set in the contemporary American South and traces one tumultuous summer in the life of a 14-year-old girl named Carolina Wells. The plot of the story is as follows: Carolina, a 14-year-old girl from Crow, Florida, does not understand her mother and remembers little about her past. In the story, we meet Carolina, her mother, "Mama," and two brothers, Johnny and Austin. Carolina does not understand her mother and her wild nature. At home, Carolina is forced to care for her two younger brothers. Carolina's father is long gone out of the picture, and Carolina was always told by her mother that she has no father - no one worth speaking of, anyway. Carolina can't remember why her father is gone, but remembers the fight that caused him to leave, and she blames her mother entirely for his leaving when she was just a toddler. Carolina questions her Mama about the disappearance of her father, but she refuses to even speak his name. Carolina desperately wants normalcy, family, and love - through a series of life-changing events involving a range of characters, including a spiritual woman across Tumbleweed Road, a mysterious girl named West and an old friend named Cade, this novel is about Carolina's quest to find her place in this world.

No description available.

In the era of big data, it is essential to implement practical security and privacy measures to ensure the lawful use of data and provide users with trust and assurance. In the dissertation, I address this issue through several key steps. Firstly, I delve into the problem of conditional secret disclosure, representing it using graphs to determine the most efficient approach for storing and disclosing secrets. Secondly, I extend the conditional disclosure of secrets problem from a single secret to multiple secrets and from a bipartite graph to an arbitrary graph. Thirdly, I remove security constraints to observe how they affect the efficiency of storage and recovery. In our final paper, I explore the secure summation problem, aiming to determine the capacity of total noise. Throughout the dissertation, I leverage information-theoretic tools to address security and privacy concerns.