Systematizing Decentralization and Privacy: Lessons from 15 Years of Research and Deployments

Decentralized systems are a subset of distributed systems where multiple authorities control different components and no authority is fully trusted by all. This implies that any component in a decentralized system is potentially adversarial. We revise fifteen years of research on decentralization and privacy, and provide an overview of key systems, as well as key insights for designers of future systems. We show that decentralized designs can enhance privacy, integrity, and availability but also require careful trade-offs in terms of system complexity, properties provided, and degree of decentralization. These trade-offs need to be understood and navigated by designers. We argue that a combination of insights from cryptography, distributed systems, and mechanism design, aligned with the development of adequate incentives, are necessary to build scalable and successful privacy-preserving decentralized systems

Data Privacy and Trust in Cloud Computing

This open access book brings together perspectives from multiple disciplines including psychology, law, IS, and computer science on data privacy and trust in the cloud. Cloud technology has fueled rapid, dramatic technological change, enabling a level of connectivity that has never been seen before in human history. However, this brave new world comes with problems. Several high-profile cases over the last few years have demonstrated cloud computing's uneasy relationship with data security and trust. This volume explores the numerous technological, process and regulatory solutions presented in academic literature as mechanisms for building trust in the cloud, including GDPR in Europe. The massive acceleration of digital adoption resulting from the COVID-19 pandemic is introducing new and significant security and privacy threats and concerns. Against this backdrop, this book provides a timely reference and organising framework for considering how we will assure privacy and build trust in such a hyper-connected digitally dependent world. This book presents a framework for assurance and accountability in the cloud and reviews the literature on trust, data privacy and protection, and ethics in cloud computing

Extending the Exposure Score of Web Browsers by Incorporating CVSS

When browsing the Internet, HTTP headers enable both clients and servers send extra data in their requests or responses such as the User-Agent string. This string contains information related to the sender’s device, browser, and operating system. Yet its content differs from one browser to another. Despite the privacy and security risks of User-Agent strings, very few works have tackled this problem. Our previous work proposed giving Internet browsers exposure relative scores to aid users to choose less intrusive ones. Thus, the objective of this work is to extend our previous work through: first, conducting a user study to identify its limitations. Second, extending the exposure score via incorporating data from the NVD. Third, providing a full implementation, instead of a limited prototype. The proposed system: assigns scores to users’ browsers upon visiting our website. It also suggests alternative safe browsers, and finally it allows updating the back-end database with a click of a button. We applied our method to a data set of more than 52 thousand unique browsers. Our performance and validation analysis show that our solution is accurate and efficient. The source code and data set are publicly available here [4].</p

Security in Cloud Computing: Evaluation and Integration

Au cours de la dernière décennie, le paradigme du Cloud Computing a révolutionné la manière dont nous percevons les services de la Technologie de l’Information (TI). Celui-ci nous a donné l’opportunité de répondre à la demande constamment croissante liée aux besoins informatiques des usagers en introduisant la notion d’externalisation des services et des données. Les consommateurs du Cloud ont généralement accès, sur demande, à un large éventail bien réparti d’infrastructures de TI offrant une pléthore de services. Ils sont à même de configurer dynamiquement les ressources du Cloud en fonction des exigences de leurs applications, sans toutefois devenir partie intégrante de l’infrastructure du Cloud. Cela leur permet d’atteindre un degré optimal d’utilisation des ressources tout en réduisant leurs coûts d’investissement en TI. Toutefois, la migration des services au Cloud intensifie malgré elle les menaces existantes à la sécurité des TI et en crée de nouvelles qui sont intrinsèques à l’architecture du Cloud Computing. C’est pourquoi il existe un réel besoin d’évaluation des risques liés à la sécurité du Cloud durant le procédé de la sélection et du déploiement des services. Au cours des dernières années, l’impact d’une efficace gestion de la satisfaction des besoins en sécurité des services a été pris avec un sérieux croissant de la part des fournisseurs et des consommateurs. Toutefois, l’intégration réussie de l’élément de sécurité dans les opérations de la gestion des ressources du Cloud ne requiert pas seulement une recherche méthodique, mais aussi une modélisation méticuleuse des exigences du Cloud en termes de sécurité. C’est en considérant ces facteurs que nous adressons dans cette thèse les défis liés à l’évaluation de la sécurité et à son intégration dans les environnements indépendants et interconnectés du Cloud Computing. D’une part, nous sommes motivés à offrir aux consommateurs du Cloud un ensemble de méthodes qui leur permettront d’optimiser la sécurité de leurs services et, d’autre part, nous offrons aux fournisseurs un éventail de stratégies qui leur permettront de mieux sécuriser leurs services d’hébergements du Cloud. L’originalité de cette thèse porte sur deux aspects : 1) la description innovatrice des exigences des applications du Cloud relativement à la sécurité ; et 2) la conception de modèles mathématiques rigoureux qui intègrent le facteur de sécurité dans les problèmes traditionnels du déploiement des applications, d’approvisionnement des ressources et de la gestion de la charge de travail au coeur des infrastructures actuelles du Cloud Computing. Le travail au sein de cette thèse est réalisé en trois phases.----------ABSTRACT: Over the past decade, the Cloud Computing paradigm has revolutionized the way we envision IT services. It has provided an opportunity to respond to the ever increasing computing needs of the users by introducing the notion of service and data outsourcing. Cloud consumers usually have online and on-demand access to a large and distributed IT infrastructure providing a plethora of services. They can dynamically configure and scale the Cloud resources according to the requirements of their applications without becoming part of the Cloud infrastructure, which allows them to reduce their IT investment cost and achieve optimal resource utilization. However, the migration of services to the Cloud increases the vulnerability to existing IT security threats and creates new ones that are intrinsic to the Cloud Computing architecture, thus the need for a thorough assessment of Cloud security risks during the process of service selection and deployment. Recently, the impact of effective management of service security satisfaction has been taken with greater seriousness by the Cloud Service Providers (CSP) and stakeholders. Nevertheless, the successful integration of the security element into the Cloud resource management operations does not only require methodical research, but also necessitates the meticulous modeling of the Cloud security requirements. To this end, we address throughout this thesis the challenges to security evaluation and integration in independent and interconnected Cloud Computing environments. We are interested in providing the Cloud consumers with a set of methods that allow them to optimize the security of their services and the CSPs with a set of strategies that enable them to provide security-aware Cloud-based service hosting. The originality of this thesis lies within two aspects: 1) the innovative description of the Cloud applications’ security requirements, which paved the way for an effective quantification and evaluation of the security of Cloud infrastructures; and 2) the design of rigorous mathematical models that integrate the security factor into the traditional problems of application deployment, resource provisioning, and workload management within current Cloud Computing infrastructures. The work in this thesis is carried out in three phases

MSL Framework: (Minimum Service Level Framework) for cloud providers and users

Cloud Computing ensures parallel computing and emerged as an efficient technology to meet the challenges of rapid growth of data that we experienced in this Internet age. Cloud computing is an emerging technology that offers subscription based services, and provide different models such as IaaS, PaaS and SaaS among other models to cater the needs of different user groups. The technology has enormous benefits but there are serious concerns and challenges related to lack of uniform standards or nonexistence of minimum benchmark for level of services offered across the industry to provide an effective, uniform and reliable service to the cloud users. As the cloud computing is gaining popularity, organizations and users are having problems to adopt the service ue to lack of minimum service level framework which can act as a benchmark in the selection of the cloud provider and provide quality of service according to the user’s expectations. The situation becomes more critical due to distributed nature of the service provider which can be offering service from any part of the world. Due to lack of minimum service level framework that will act as a benchmark to provide a uniform service across the industry there are serious concerns raised recently interms of security and data privacy breaches, authentication and authorization issues, lack of third party audit and identity management problems, integrity, confidentiality and variable data availability standards, no uniform incident response and monitoring standards, interoperability and lack of portability standards, identity management issues, lack of infrastructure protection services standards and weak governance and compliance standards are major cause of concerns for cloud users. Due to confusion and absence of universal agreed SLAs for a service model, different quality of services is being provided across the cloud industry. Currently there is no uniform performance model agreed by all stakeholders; which can provide performance criteria to measure, evaluate, and benchmark the level of services offered by various cloud providers in the industry. With the implementation of General Data Protection Regulation (GDPR) and demand from cloud users to have Green SLAs that provides better resource allocations mechanism, there will be serious implications for the cloud providers and its consumers due to lack of uniformity in SLAs and variable standards of service offered by various cloud providers. This research examines weaknesses in service level agreements offered by various cloud providers and impact due to absence of uniform agreed minimum service level framework on the adoption and usage of cloud service. The research is focused around higher education case study and proposes a conceptual model based on uniform minimum service model that acts as benchmark for the industry to ensure quality of service to the cloud users in the higher education institution and remove the barriers to the adoption of cloud technology. The proposed Minimum Service Level (MSL) framework, provides a set of minimum and uniform standards in the key concern areas raised by the participants of HE institution which are essential to the cloud users and provide a minimum quality benchmark that becomes a uniform standard across the industry. The proposed model produces a cloud computing implementation evaluation criteria which is an attempt to reduce the adoption barrier of the cloud technology and set minimum uniform standards followed by all the cloud providers regardless of their hosting location so that their performance can be measured, evaluated and compared across the industry to improve the overall QoS (Quality of Service) received by the cloud users, remove the adoption barriers and concerns of the cloud users and increase the competition across the cloud industry.A computação em nuvem proporciona a computação paralela e emergiu como uma tecnologia eficiente para enfrentar os desafios do crescimento rápido de dados que vivemos na era da Internet. A computação em nuvem é uma tecnologia emergente que oferece serviços baseados em assinatura e oferece diferentes modelos como IaaS, PaaS e SaaS, entre outros modelos para atender as necessidades de diferentes grupos de utilizadores. A tecnologia tem enormes benefícios, mas subsistem sérias preocupações e desafios relacionados com a falta de normas uniformes ou inexistência de um referencial mínimo para o nível de serviços oferecidos, na indústria, para proporcionar uma oferta eficaz, uniforme e confiável para os utilizadores da nuvem. Como a computação em nuvem está a ganhar popularidade, tanto organizações como utilizadores estão enfrentando problemas para adotar o serviço devido à falta de enquadramento de nível de serviço mínimo que possa agir como um ponto de referência na seleção de provedor da nuvem e fornecer a qualidade dos serviços de acordo com as expectativas do utilizador. A situação torna-se mais crítica, devido à natureza distribuída do prestador de serviço, que pode ser oriundo de qualquer parte do mundo. Devido à falta de enquadramento de nível de serviço mínimo que irá agir como um benchmark para fornecer um serviço uniforme em toda a indústria, existem sérias preocupações levantadas recentemente em termos de violações de segurança e privacidade de dados, autenticação e autorização, falta de questões de auditoria de terceiros e problemas de gestão de identidade, integridade, confidencialidade e disponibilidade de dados, falta de uniformidade de normas, a não resposta a incidentes e o monitoramento de padrões, a interoperabilidade e a falta de padrões de portabilidade, questões relacionadas com a gestão de identidade, falta de padrões de serviços de proteção das infraestruturas e fraca governança e conformidade de padrões constituem outras importantes causas de preocupação para os utilizadores. Devido à confusão e ausência de SLAs acordados de modo universal para um modelo de serviço, diferente qualidade de serviços está a ser fornecida através da nuvem, pela indústria da computação em nuvem. Atualmente, não há desempenho uniforme nem um modelo acordado por todas as partes interessadas; que pode fornecer critérios de desempenho para medir, avaliar e comparar o nível de serviços oferecidos por diversos fornecedores de computação em nuvem na indústria. Com a implementação do Regulamento Geral de Protecção de Dados (RGPD) e a procura da nuvem com base no impacto ambiental (Green SLAs), são acrescentadas precupações adicionais e existem sérias implicações para os forncedores de computação em nuvem e para os seus consumidores, também devido à falta de uniformidade na multiplicidade de SLAs e padrões de serviço oferecidos. A presente pesquisa examina as fraquezas em acordos de nível de serviço oferecidos por fornecedores de computação em nuvem e estuda o impacto da ausência de um quadro de nível de serviço mínimo acordado sobre a adoção e o uso no contexto da computação em nuvem. A pesquisa está orientada para a adoção destes serviços para o caso do ensino superior e as instituições de ensino superior e propõe um modelo conceptualt com base em um modelo de serviço mínimo uniforme que funciona como referência para a indústria, para garantir a qualidade do serviço para os utilizadores da nuvem numa instituição de ensino superior de forma a eliminar as barreiras para a adoção da tecnologia de computação em nuvem. O nível de serviço mínimo proposto (MSL), fornece um conjunto mínimo de normas uniformes e na áreas das principais preocupações levantadas por responsáveis de instituições de ensino superior e que são essenciais, de modo a fornecer um referencial mínimo de qualidade, que se possa tornar um padrão uniforme em toda a indústria. O modelo proposto é uma tentativa de reduzir a barreira de adoção da tecnologia de computação em nuvem e definir normas mínimas seguidas por todos os fornecedores de computação em nuvem, independentemente do seu local de hospedagem para que os seus desempenhos possam ser medidos, avaliados e comparados em toda a indústria, para melhorar a qualidade de serviço (QoS) recebida pelos utilizadores e remova as barreiras de adoção e as preocupações dos utilizadores, bem como fomentar o aumento da concorrência em toda a indústria da computação em nuvem

MSL Framework: (Minimum Service Level Framework) for Cloud Providers and Users

Cloud Computing ensures parallel computing and emerged as an efficient technology to meet the challenges of rapid growth of data that we experienced in this Internet age. Cloud computing is an emerging technology that offers subscription based services, and provide different models such as IaaS, PaaS and SaaS among other models to cater the needs of different user groups. The technology has enormous benefits but there are serious concerns and challenges related to lack of uniform standards or nonexistence of minimum benchmark for level of services offered across the industry to provide an effective, uniform and reliable service to the cloud users. As the cloud computing is gaining popularity, organizations and users are having problems to adopt the service ue to lack of minimum service level framework which can act as a benchmark in the selection of the cloud provider and provide quality of service according to the user’s expectations. The situation becomes more critical due to distributed nature of the service provider which can be offering service from any part of the world. Due to lack of minimum service level framework that will act as a benchmark to provide a uniform service across the industry there are serious concerns raised recently interms of security and data privacy breaches, authentication and authorization issues, lack of third party audit and identity management problems, integrity, confidentiality and variable data availability standards, no uniform incident response and monitoring standards, interoperability and lack of portability standards, identity management issues, lack of infrastructure protection services standards and weak governance and compliance standards are major cause of concerns for cloud users. Due to confusion and absence of universal agreed SLAs for a service model, different quality of services is being provided across the cloud industry. Currently there is no uniform performance model agreed by all stakeholders; which can provide performance criteria to measure, evaluate, and benchmark the level of services offered by various cloud providers in the industry. With the implementation of General Data Protection Regulation (GDPR) and demand from cloud users to have Green SLAs that provides better resource allocations mechanism, there will be serious implications for the cloud providers and its consumers due to lack of uniformity in SLAs and variable standards of service offered by various cloud providers. This research examines weaknesses in service level agreements offered by various cloud providers and impact due to absence of uniform agreed minimum service level framework on the adoption and usage of cloud service. The research is focused around higher education case study and proposes a conceptual model based on uniform minimum service model that acts as benchmark for the industry to ensure quality of service to the cloud users in the higher education institution and remove the barriers to the adoption of cloud technology. The proposed Minimum Service Level (MSL) framework, provides a set of minimum and uniform standards in the key concern areas raised by the participants of HE institution which are essential to the cloud users and provide a minimum quality benchmark that becomes a uniform standard across the industry. The proposed model produces a cloud computing implementation evaluation criteria which is an attempt to reduce the adoption barrier of the cloud technology and set minimum uniform standards followed by all the cloud providers regardless of their hosting location so that their performance can be measured, evaluated and compared across the industry to improve the overall QoS (Quality of Service) received by the cloud users, remove the adoption barriers and concerns of the cloud users and increase the competition across the cloud industry.A computação em nuvem proporciona a computação paralela e emergiu como uma tecnologia eficiente para enfrentar os desafios do crescimento rápido de dados que vivemos na era da Internet. A computação em nuvem é uma tecnologia emergente que oferece serviços baseados em assinatura e oferece diferentes modelos como IaaS, PaaS e SaaS, entre outros modelos para atender as necessidades de diferentes grupos de utilizadores. A tecnologia tem enormes benefícios, mas subsistem sérias preocupações e desafios relacionados com a falta de normas uniformes ou inexistência de um referencial mínimo para o nível de serviços oferecidos, na indústria, para proporcionar uma oferta eficaz, uniforme e confiável para os utilizadores da nuvem. Como a computação em nuvem está a ganhar popularidade, tanto organizações como utilizadores estão enfrentando problemas para adotar o serviço devido à falta de enquadramento de nível de serviço mínimo que possa agir como um ponto de referência na seleção de provedor da nuvem e fornecer a qualidade dos serviços de acordo com as expectativas do utilizador. A situação torna-se mais crítica, devido à natureza distribuída do prestador de serviço, que pode ser oriundo de qualquer parte do mundo. Devido à falta de enquadramento de nível de serviço mínimo que irá agir como um benchmark para fornecer um serviço uniforme em toda a indústria, existem sérias preocupações levantadas recentemente em termos de violações de segurança e privacidade de dados, autenticação e autorização, falta de questões de auditoria de terceiros e problemas de gestão de identidade, integridade, confidencialidade e disponibilidade de dados, falta de uniformidade de normas, a não resposta a incidentes e o monitoramento de padrões, a interoperabilidade e a falta de padrões de portabilidade, questões relacionadas com a gestão de identidade, falta de padrões de serviços de proteção das infraestruturas e fraca governança e conformidade de padrões constituem outras importantes causas de preocupação para os utilizadores. Devido à confusão e ausência de SLAs acordados de modo universal para um modelo de serviço, diferente qualidade de serviços está a ser fornecida através da nuvem, pela indústria da computação em nuvem. Atualmente, não há desempenho uniforme nem um modelo acordado por todas as partes interessadas; que pode fornecer critérios de desempenho para medir, avaliar e comparar o nível de serviços oferecidos por diversos fornecedores de computação em nuvem na indústria. Com a implementação do Regulamento Geral de Protecção de Dados (RGPD) e a procura da nuvem com base no impacto ambiental (Green SLAs), são acrescentadas precupações adicionais e existem sérias implicações para os forncedores de computação em nuvem e para os seus consumidores, também devido à falta de uniformidade na multiplicidade de SLAs e padrões de serviço oferecidos. A presente pesquisa examina as fraquezas em acordos de nível de serviço oferecidos por fornecedores de computação em nuvem e estuda o impacto da ausência de um quadro de nível de serviço mínimo acordado sobre a adoção e o uso no contexto da computação em nuvem. A pesquisa está orientada para a adoção destes serviços para o caso do ensino superior e as instituições de ensino superior e propõe um modelo conceptualt com base em um modelo de serviço mínimo uniforme que funciona como referência para a indústria, para garantir a qualidade do serviço para os utilizadores da nuvem numa instituição de ensino superior de forma a eliminar as barreiras para a adoção da tecnologia de computação em nuvem. O nível de serviço mínimo proposto (MSL), fornece um conjunto mínimo de normas uniformes e na áreas das principais preocupações levantadas por responsáveis de instituições de ensino superior e que são essenciais, de modo a fornecer um referencial mínimo de qualidade, que se possa tornar um padrão uniforme em toda a indústria. O modelo proposto é uma tentativa de reduzir a barreira de adoção da tecnologia de computação em nuvem e definir normas mínimas seguidas por todos os fornecedores de computação em nuvem, independentemente do seu local de hospedagem para que os seus desempenhos possam ser medidos, avaliados e comparados em toda a indústria, para melhorar a qualidade de serviço (QoS) recebida pelos utilizadores e remova as barreiras de adoção e as preocupações dos utilizadores, bem como fomentar o aumento da concorrência em toda a indústria da computação em nuvem

Performance Evaluation of three Data Access Control Schemes for Cloud Computing

Cloud services are flourishing recently, both among computer users and business enterprises. They deliver remote, on-demand, convenient services for data storage, access and processing. While embracing the benefits brought by various cloud services, the consumers are faced with data disclosure, privacy leaks and malicious attacks. Therefore, it is important to use strong access control policies to maintain the security and confidentiality of the data stored in the cloud. This thesis studies the performance of three existing security schemes proposed for cloud data access control on the basis of trust and reputation. We implement the three schemes and conduct computation complexity analysis, security analysis and performance evaluation. This thesis introduces the implementation of a number of cryptographic algorithms applied in the above data access control schemes, including Proxy Re-encryption (PRE) and Ciphertext-Policy Attribute Based Encryption (CP-ABE), reputation generation and secure data transmission over Secure Socket Layer (SSL). We summarize the evaluation results and compare the performances in the aspects of computation and communication costs, flexibility, scalability and feasibility of practical usage. Pros and cons, as well as suitable application scenarios of the three schemes are further discussed

End-to-end security in service-oriented architecture

A service-oriented architecture (SOA)-based application is composed of a number of distributed and loosely-coupled web services, which are orchestrated to accomplish a more complex functionality. Any of these web services is able to invoke other web services to offload part of its functionality. The main security challenge in SOA is that we cannot trust the participating web services in a service composition to behave as expected all the time. In addition, the chain of services involved in an end-to-end service invocation may not be visible to the clients. As a result, any violation of client’s policies could remain undetected. To address these challenges in SOA, we proposed the following contributions. First, we devised two composite trust schemes by using graph abstraction to quantitatively maintain the trust levels of different services. The composite trust values are based on feedbacks from the actual execution of services, and the structure of the SOA application. To maintain the dynamic trust, we designed the trust manager, which is a trusted-third party service. Second, we developed an end-to-end inter-service policy monitoring and enforcement framework (PME framework), which is able to dynamically inspect the interactions between services at runtime and react to the potentially malicious activities according to the client’s policies. Third, we designed an intra-service policy monitoring and enforcement framework based on taint analysis mechanism to monitor the information flow within services and prevent information disclosure incidents. Fourth, we proposed an adaptive and secure service composition engine (ASSC), which takes advantage of an efficient heuristic algorithm to generate optimal service compositions in SOA. The service compositions generated by ASSC maximize the trustworthiness of the selected services while meeting the predefined QoS constraints. Finally, we have extensively studied the correctness and performance of the proposed security measures based on a realistic SOA case study. All experimental studies validated the practicality and effectiveness of the presented solutions

PenChain: A Blockchain-Based Platform for Penalty-Aware Service Provisioning

Service provisioning is of paramount importance as we are now heading towards a world of integrated services giving rise to the next generation of service ecosystems. The huge number of service offerings that will be available to customers in future scenarios require a novel approach to service registry and discovery that allows customers to choose the offerings that best match their preferences. One way to achieve this is to introduce the provider’s reputation, i.e., a quality indicator of the provisioned service, as an additional search criterion. Now, with blockchain technology in our hands, automated regulation of service-level agreements (SLAs) that capture mutual agreements between all involved parties has regained momentum. In this article, we report on our full-fledged work on the conception, design, and construction of a platform for SLA-minded service provisioning called PenChain. With our work, we demonstrate that penalty-aware SLAs of general services–if represented in machine-readable logic and assisted by distributed ledger technology–are programmatically enforceable. We devise algorithms for ranking services in a search result taking into account the digitized values of the SLAs. We offer two scenario-based evaluations of PenChain in the field of precision agriculture and in the domain of automotive manufacturing. Furthermore, we examine the scalability and data security of PenChain for precision agriculture