La tolérance et la gestion des fautes dans les grilles de données/calcul est d’une importance capitale. En effet, comme dans tout autre système distribué, les composants d’une grille sont susceptibles de tomber en panne à tout moment. Mais le risque de panne croît avec la taille du système, et est donc plus exacerbé dans un système de grille. En plus, tout en essayant de mettre à profit les ressources offertes par la grille, les applications tournant sur celle-ci sont de plus en plus complexes (ex. impliquent des interactions complexes, prennent des jours d’exécution), ce qui les rend plus vulnérables aux fautes. Le plus difficile dans la gestion des fautes dans une grille, c’est qu’il est difficile de savoir si une faute qui survient sur une entité de la grille est induite malicieusement ou accidentellement. Dans notre travail de thèse, nous utilisons le terme faute, au sens large, pour faire référence à tout étant inattendu qui survient sur tout composant de la grille. Certains de ces états provoquent des comportements aussi inattendus et perceptibles au niveau de la grille tandis que d’autres passent inaperçues. De plus, certaines de ces fautes sont le résultat d’une action malveillante alors que d’autres surviennent accidentellement ou instantanément. Dans ce travail de thèse, nous avons traité le cas de ces fautes induites malicieusement, et qui généralement passent inaperçues. Nous avons considéré en particulier le problème de la confidentialité et de l’intégrité des données stockées à long-terme sur la grille. L’étude de la confidentialité des données a été faite en deux temps dont la première partie concerne la confidentialité des données actives. Dans cette partie, nous avons considéré une application liée à la recherche des similitudes d’une séquence d’ADN dans une base de données contenant des séquences d’ADN et stockée sur la grille. Pour cela, nous avons proposé une méthode qui permet d’effectuer la comparaison sur un composant distant, mais tout en gardant confidentielle la séquence qui fait l’objet de la comparaison. Concernant les données passives, nous avons proposé une méthode de partage des données confidentielles et chiffrés sur la grille. En rapport avec l’intégrité des données, nous avons considéré le cas des données anonymes dans le cadre de l’intégrité des données passives. Pour les données actives, nous avons considéré le problème de la corruption des jobs exécutés sur la grille. Pour chacune des cas, nous avons proposé des mécanismes permettant de vérifier l’authenticité des données utilisées ou produites par ces applications.

Releasing synthetic data in place of observed values is a method of statistical disclosure control for the public dissemination of survey data collected by national statistical agencies. The overall goal is to limit the risk of disclosure of survey respondents' identities or sensitive attributes, but simultaneously retain enough detail in the synthetic data to preserve the inferential conclusions drawn on the target population, in potential future legitimate statistical analyses. This thesis presents three new research contributions in the analysis and application of synthetic data. Firstly, to understand differences in types of input between the imputer, typically an agency, and the analyst, we present a definition of congeniality in the context of multiple imputation for synthetic data. Our definition is motivated by common examples of uncongeniality, specifically ignorance of the original survey design in analysis of fully synthetic data, and situations when the imputation model and analysis procedure condition upon different sets of records. We conclude that our definition provides a framework to assist the imputer to identify the source of a discrepancy between observed and synthetic data analytic results. Motivated by our definition, we derive an alternative approach to synthetic data inference, to recover the observed data set sampling distribution of sufficient statistics given the synthetic data. Secondly, we address the problem of negative method-of-moments variance estimates given fully synthetic data, which may be produced with the current inferential methods. We apply the adjustment for density maximization (ADM) method to variance estimation, and demonstrate using ADM as an alternative approach to produce positive variance estimates. Thirdly, we present a new application of synthetic data techniques to confidentialize survey data from a large-scale healthcare study. To date, application of synthetic data techniques to healthcare survey data is rare. We discuss identification of variables for synthesis, specification of imputation models, and working measures of disclosure risk assessment. Following comparison of observed and synthetic data analytic results based on published studies, we conclude that use of synthetic data for our healthcare survey is best suited for exploratory data analytic purposes. / Statistics

Usage of mobile applications and wireless networks is growing rapidly at different sectors in the world. Mobile healthcare application is devotedly accepted by the healthcare organizations and also by patients. The reasons behind accepting mobile healthcare applications are as user friendly, reliable, low cost, time efficient, mobility etc. Though the use of mobile applications is rising day by day in the healthcare sectors still those applications are not completely secure to prevent disclosure and misuse of patient’s sensitive data. However, security issues in healthcare applications get attention by many organizations. In this thesis we have presented an integrated architecture for secure mobile healthcare system. This application provides management of patient medical records in a regional environment. Our mobile application is developed for Android platform. This solution is secure enough, because it fulfills important security requirements: integrity, confidentiality and availability.

No description available.

Yes / With the advent of Wireless Sensor Networks (WSN) and its immense popularity in a wide range of applications, security has been a major concern for these resource-constraint systems. Alongside security, WSNs are currently being integrated with existing technologies such as the Internet, satellite, Wi-Max, Wi-Fi, etc. in order to transmit data over long distances and hand-over network load to more powerful devices. With the focus currently being on the integration of WSNs with existing technologies, security becomes a major concern. The main security requirement for WSN-integrated networks is providing end-to-end security along with the implementation of in-processing techniques of data aggregation. This can be achieved with the implementation of Homomorphic encryption schemes which prove to be computationally inexpensive since they have considerable overheads. This paper addresses the ID-issue of the commonly used Castelluccia Mykletun Tsudik (CMT) [12] homomorphic scheme by proposing an ID slotting mechanism which carries information pertaining to the security keys responsible for the encryption of individual sensor data. The proposed scheme proves to be 93.5% lighter in terms of induced overheads and 11.86% more energy efficient along with providing efficient WSN scalability compared to the existing scheme. The paper provides analytical results comparing the proposed scheme with the existing scheme thus justifying that the modification to the existing scheme can prove highly efficient for resource-constrained WSNs.

Submitted by SBI Biblioteca Digital (sbi.bibliotecadigital@puc-campinas.edu.br) on 2017-01-19T13:28:00Z No. of bitstreams: 1 Silvana Bordini Coca Machado.pdf: 2197792 bytes, checksum: e1d90aedeee97ffbdaa9adcd79a31400 (MD5) / Made available in DSpace on 2017-01-19T13:28:00Z (GMT). No. of bitstreams: 1 Silvana Bordini Coca Machado.pdf: 2197792 bytes, checksum: e1d90aedeee97ffbdaa9adcd79a31400 (MD5) Previous issue date: 2016-11-28 / According to the United Nations report, 2014, for the first time in history, most of the world's population is living in urban centers. The urbanization movement, from 1950 to the present day, presented a migration from rural areas to urban almost doubling the reality of that time, which was 30%. And by 2050, it is expected that to be over 66% urban population. That is, the available infrastructure and services should be sized to meet this rapid growth and in less than a century. The information from these citizens, requiring for services provision of care for health, education, transportation and security, are stored in various systems, which may not part of any data centralization and standardization. Many data feature personal information, such as national registers, addresses, and others, which are not well safeguarded and can be a door to the leakage and misuse. The technologies used for the collection and storage of data can affect significantly the lives of people by emerging problems with security and data privacy. The ISO 27001 standard defines the triple constraint for information security through confidentiality, integrity and availability. In order to take the emergence of Smart Cities in the context, which are based on the provision of services via communication highways and by which provide information to governmental agencies, institutions in general and to every citizen. This study aims to learn how to make proper use of data personal institutions under security protection. In this context, they are seeking transparency and agility through ICT, which can be seen during this study that effective confidentiality requires even greater attention from managers and any team responsible for collecting, processing and distributing information. This result for this research is the proposition of a method for public organizations on how to handle data and information related to privacy, using a method based on decision making with the Analytic Hierarchy Process (AHP) and data subsets evaluation. / Segundo relat?rio da ONU, Organiza??o das Na??es Unidas, de 2014, pela primeira vez na hist?ria, a maior parte da popula??o mundial est? vivendo em centros urbanos. O movimento de urbaniza??o, desde 1950 at? os dias atuais, apresentou uma imigra??o da ?rea rural para a urbana quase dobrando a realidade daquela ?poca, a qual era de 30%, e at? 2050, espera-se uma popula??o urbana superior a 66%. A infra-estrutura e os servi?os oferecidos dever?o estar dimensionados para atender a este aumento populacional. A informa??o destes cidad?os, necess?ria para provimento de atendimentos n?o apenas da sa?de, educa??o, transporte e seguran?a s?o armazenadas nos mais diversos sistemas, sem que haja obrigatoriamente uma centraliza??o e padroniza??o destes dados. Muitos dados caracterizam informa??es pessoais, como registros nacionais, endere?os, que devem ser salvo-guardados adequadamente, caso contr?rio, podem ser uma porta para o vazamento e mal-uso dos mesmos. As tecnologias utilizadas para coleta e armazenamento dos dados podem afetar sensivelmente a vida da popula??o surgindo ent?o os problemas com a seguran?a e a privacidade de dados. A norma ISO 27001 define o trip? da seguran?a da informa??o por meio da confidencialidade, integridade e disponibilidade, buscando contextualizar a emerg?ncia das Cidades Inteligentes, que se fundamentam na oferta de servi?os via infovias de comunica??o e pelas quais s?o disponibilizadas informa??es a ?rg?os governamentais, institui??es em geral e a todo cidad?o. Este trabalho tem por objetivo apreender como fazer o uso adequado de dados pessoais nas institui??es, perante esta ?tica de prote??o, ao mesmo tempo em que, principalmente, com rela??o aos ?rg?os p?blicos se exige transpar?ncia. Nesse contexto em que se busca transpar?ncia e agilidade por meio das tecnologias da informa??o e comunica??o, se observar? no decorrer desta pesquisa que efetivos cuidados com a confidencialidade exigem ainda maior aten??o dos gestores e respons?veis pela coleta, processamento e distribui??o da informa??o. O resultado obtido foi a proposi??o de uma metodologia para o tratamento de dados e informa??es privadas pelas institui??es p?blicas, utilizando-se modelo de apoio a decis?o Analytical Hierachical Process (AHP) e avalia??o de subconjuntos de dados.

International entrepreneurship (IE) is “a combination of innovative, proactive and risk-seeking behaviour that crosses national borders and is intended to create value in organizations”. The IE literature has been concerned with entrepreneurial behaviour in multiple countries and cross-border studies of entrepreneurship and international activities of small and medium-sized enterprises (SME). Due to the potential for SMEs to serve as significant sources of export, considerable research has been conducted regarding their internationalization. However, despite attempts to integrate concrete frameworks of international entrepreneurship, some primary issues have not been adequately addressed and IE researchers are faced with challenges including insufficient micro-data for advancing quality research. The main objective of this thesis is to study and explore the limitations on researchers to access governmental data regarding small firms operating internationally and use it for scientific purposes. Despite company data being compiled and publicly available in some countries, such as Germany, other countries, including Canada, have not made any such efforts in a coherent way. There is a significant disconnect in the Canadian context between internationalization and firms’ data. This shortcoming may stem from various sources, including the legal framework in Canada for accessing data and a lack of sufficient financial support and expertise to gather and integrate such data. Furthermore, the type of data available to the research community through statistical institutions were identified and analyzed, as were access methods. With the increasing interest of researchers in accessing data gathered by the government, the formation of anonymized records or anonymized micro-datasets has acquired great importance. Therefore, the primary approach is to explore the extent to which data regarding firms’ characteristics and internationalization activities are currently available to the research community, as well as to ensure the confidentiality of official statistics, most notably in the Canadian context. The research resulted in the confirmation of data availability in Canada through government and statistical organizations. The latter bodies can provide researchers and research organizations access to some data but limitations arise in providing micro-datasets to researchers due to confidentiality issues; these constraints were identified and further analyzed. Moreover, this research has studied methods to overcome these limitations and assess the shortcomings in micro-data in order to advance quality research. Methods and recommendations were introduced and studied to allow researchers access to essential data and information while maintaining confidentiality.

International entrepreneurship (IE) is “a combination of innovative, proactive and risk-seeking behaviour that crosses national borders and is intended to create value in organizations”. The IE literature has been concerned with entrepreneurial behaviour in multiple countries and cross-border studies of entrepreneurship and international activities of small and medium-sized enterprises (SME). Due to the potential for SMEs to serve as significant sources of export, considerable research has been conducted regarding their internationalization. However, despite attempts to integrate concrete frameworks of international entrepreneurship, some primary issues have not been adequately addressed and IE researchers are faced with challenges including insufficient micro-data for advancing quality research. The main objective of this thesis is to study and explore the limitations on researchers to access governmental data regarding small firms operating internationally and use it for scientific purposes. Despite company data being compiled and publicly available in some countries, such as Germany, other countries, including Canada, have not made any such efforts in a coherent way. There is a significant disconnect in the Canadian context between internationalization and firms’ data. This shortcoming may stem from various sources, including the legal framework in Canada for accessing data and a lack of sufficient financial support and expertise to gather and integrate such data. Furthermore, the type of data available to the research community through statistical institutions were identified and analyzed, as were access methods. With the increasing interest of researchers in accessing data gathered by the government, the formation of anonymized records or anonymized micro-datasets has acquired great importance. Therefore, the primary approach is to explore the extent to which data regarding firms’ characteristics and internationalization activities are currently available to the research community, as well as to ensure the confidentiality of official statistics, most notably in the Canadian context. The research resulted in the confirmation of data availability in Canada through government and statistical organizations. The latter bodies can provide researchers and research organizations access to some data but limitations arise in providing micro-datasets to researchers due to confidentiality issues; these constraints were identified and further analyzed. Moreover, this research has studied methods to overcome these limitations and assess the shortcomings in micro-data in order to advance quality research. Methods and recommendations were introduced and studied to allow researchers access to essential data and information while maintaining confidentiality.

Yes / The recent advancements in wireless sensor hardware ensures sensing multiple sensor data such as temperature, pressure, humidity, etc. using a single hardware unit, thus defining it as multi-sensor data communication in wireless sensor networks (WSNs). The in-processing technique of data aggregation is crucial in energy-efficient WSNs; however, with the requirement of end-to-end data confidentiality it may prove to be a challenge. End-to-end data confidentiality along with data aggregation is possible with the implementation of a special type of encryption scheme called privacy homomorphic (PH) encryption schemes. This paper proposes an optimized PH encryption scheme for WSN integrated networks handling multi-sensor data. The proposed scheme ensures light-weight payloads, significant energy and bandwidth consumption along with lower latencies. The performance analysis of the proposed scheme is presented in this paper with respect to the existing scheme. The working principle of the multi-sensor data framework is also presented in this paper along with the appropriate packet structures and process. It can be concluded that the scheme proves to decrease the payload size by 56.86% and spend an average energy of 8-18 mJ at the aggregator node for sensor nodes varying from 10-50 thereby ensuring scalability of the WSN unlike the existing scheme.

Dans cette thèse, nous nous intéressons au problème de la confidentialité des données. Nous proposons une nouvelle approche pour faciliter l'administration des règles de contrôle d'accès pour assurer la confidentialité des données au niveau des vues matérialisées. Dans les bases de données relationnelles, une vue est une table virtuelle représentant le résultat d'une requête. À la différence d'une vue simple, une vue matérialisée stocke le résultat de la requête dans une table. Cette dernière peut être alors interrogée comme une table quelconque. Il est donc important d'y contrôler l'accès. Parmi les différents modèles proposés pour contrôler l'accès aux relations de base, nous nous basons dans notre approche sur l'utilisation des vues d'autorisations pour exprimer des règles de contrôle d'accès à grains fins. Nous proposons d'inférer, à partir des vues d'autorisations attachées aux tables de base, les vues d'autorisations qui doivent être attachées aux vues matérialisées. Répondre à ce problème revient à répondre à un problème fondamental dans les bases de données relationnelles : Comment caractériser les informations calculables à partir de deux ensembles de vues ? Nous répondons à cette question en nous appuyant sur la réécriture de requêtes. Nous adaptons l'algorithme de réécriture de requêtes M iniCon aux spécificités de notre problème et nous proposons l'algorithme 1-l M iniCon+ qui se base sur un enchainement de réécritures. Nous nous intéressons aux vues représentées par des requêtes conjonctives en autorisant les égalités. Nous nous sommes intéressés par la suite aux propriétés de cet algorithme. Nous démontrons que cet algorithme permet de calculer un ensemble de vues correctes, c.-à-d. toute information calculable à partir de l'ensemble de vues générées est cal­ culable à partir de chacun des deux ensembles de vues de départ / In this thesis, we address the problem of data confidentiality. We propose a new approach to facilitate the administration of access control policies to ensure confidentiality of data in materialized views. In relational databases, a view is a virtual table representing the result of a query. Unlike a simple view, a materialized view persistently stores the data in a table. The latter can be queried like any other database table. We then need to control the access to the materialized view. Among the various models proposed for controlling access to base relations, we choose to express fine-grained access control through authorization views. We propose to infer, from the basic authorization views attached to the base tables, authorization views that will be attached to the materialized views. Tackling this problem amounts to address a fundamental problem in relational databases : How to characterize computable information from two sets of views ? We handle this problem by resorting to query rewriting. We adapt the query rewriting algorithm MiniCon to the context of materialized views with access control and propose the H MiniCon+ algorithm which is based on successive rewritings. We mainly consider conjunctive queries with equalities. We study the properties of our approach. We show that our algorithm can calculate a correct set of views, i.e. any computable information from the generated views is calculable from the two sets of views. In order to prove the termination of our algorithm, we define rewriting trees generated by the application of 1-l MiniCon+ and we study their features. We characterize in which case a tree is finite and show that the approach is maximal, i.e., any derivable information from the two sets of views can be derived from the set of generated views. We characterize in which case the algorithm could not terminate i.e., infinite application of the query rewriting algorithm. In this case, it is impossible to determine the maximality of results and this remains an open problem. We implemented a prototype of the approach and we led some experiments by using synthetic data sets