Denna kandidatuppsats behandlar säkerhet inom molnet. Med hjälp av en litteraturstudie inom ämnet kombinerat med intervjuer av företag som både använder och erbjuder molntjänster undersöker vi vad företagen har för kunskap om säkerhetsbrister inom molnet. Utöver säkerhetsfrågor har vi även belyst en rad generella frågor kring molnet; varför företag använder molnet och vad de upplever som för- och nackdelar med tjänsterna. Vidare argumenterar vi för införandet av en standard som kommer att klargöra vilka säkerhetsrutiner som molnföretagen erbjuder. Uppsatsens resultat är av intresse för den som står inför ett beslut att införa molntjänster, eller den som redan använder molnet men har funderingar kring dess säkerhetsaspekter.

Implementar una arquitectura tecnológica utilizando la tecnología de prestación de servicios de Cloud Computing que soporte los proyectos profesionales de la Escuela de Ingeniería de Sistemas y Computación (EISC). / Implement a technological architecture using Cloud Computing service provision technology that supports the professional projects of the School of Engineering of Systems and Computing (EISC).

Magíster en Ingeniería de Redes de Comunicaciones / El presente trabajo tiene como objetivo general la construcción de un curso sobre el Cloud Computing con un enfoque teórico y practico, cuyo propósito principal es que los alumnos pongan en práctica los conocimientos adquiridos a través de una serie de laboratorios diseñados y correlacionados con el programa teórico, basados en las tecnologías que son tendencia en el mercado; es por ello la importancia de la opinión de especialistas en diseño de nubes y manejo de negocios para la realización de este trabajo. El material de estudios propuesto viene a sellar el vacío práctico que existe en la oferta nacional e internacional en cuanto al estudio de tecnologías relacionadas a las construcción de nubes públicas y privadas, es por ello que se establece un punto de referencia en cuanto al temario propuesto por la industria en certificaciones de las tecnologías de información más relevantes y a los cursos universitarios relacionados al tema. Además se incluye como parte del curso, el estudio de la arquitectura y uso de un sistema operativo para nubes de código abierto, llamado OpenStack, como introducción a los alumnos interesados en el desarrollo de aplicaciones específicas sobre este sistema operativo. Se hace énfasis en el estudio de OpenStack debido a su relevancia e importancia en el mercado, así como también su uso referencial para muchos fabricantes de equipos de data centers y software de virtualización. Dicho lo anterior, el presente trabajo propone un enfoque completo a nivel técnico en el diseño de nubes, con matices de modelos de negocios en el Cloud Computing, lo cual es relevante al momento de entender el porqué del uso de esta tecnología, además de entender los beneficios más relevantes en la adopción de tecnologías basadas en la nube. De forma implícita el presente trabajo tiene como meta romper la barrera de conocimientos y relacionamiento que existe entre el personal de los departamentos de virtualización, software, redes y almacenamiento de las empresas, cuya estructura en la mayoría de los casos, presenta un reto al momento de la implementación de tecnologías que cada vez están mas relacionadas entre sí y que deben convivir con un punto de gestión centralizado.

The aim of this diploma thesis called "Cloud services utilization at Czech universities" is to compare services of Office 365 and G Suite and to evaluate their use at public universities in the Czech Republic which is examined on the basis of qualitative research. The thesis contains six parts. The first chapter characterizes the concept of cloud, its advantages, disadvantages and its models: delivery models and deployment models. The second and third parts describe the history and pricing plans of Office 365 and G Suite. Selected services for education plans are described and then compared from the schools' point of view within the fourth chapter. The fifth part focuses on the experience of cloud services (Microsoft or Google) at selected universities in the Czech Republic with the aim of identifying impulses, barriers, experiences, ideas and recommendations which could serve other colleges and which are summarized in the final part.

MapReduce, a parallel computing paradigm, has been gaining popularity in recent years as cloud vendors offer MapReduce computation services on their public clouds. However, companies are still reluctant to move their computations to the public cloud due to the following reason: In the current business model, the entire MapReduce cluster is deployed on the public cloud. If the public cloud is not properly protected, the integrity and the confidentiality of MapReduce applications can be compromised by attacks inside or outside of the public cloud. From the result integrity’s perspective, if any computation nodes on the public cloud are compromised,thosenodes can return incorrect task results and therefore render the final job result inaccurate. From the algorithmic confidentiality’s perspective, when more and more companies devise innovative algorithms and deploy them to the public cloud, malicious attackers can reverse engineer those programs to detect the algorithmic details and, therefore, compromise the intellectual property of those companies. In this dissertation, we propose to use the hybrid cloud architecture to defeat the above two threats. Based on the hybrid cloud architecture, we propose separate solutions to address the result integrity and the algorithmic confidentiality problems. To address the result integrity problem, we propose the Integrity Assurance MapReduce (IAMR) framework. IAMR performs the result checking technique to guarantee high result accuracy of MapReduce jobs, even if the computation is executed on an untrusted public cloud. We implemented a prototype system for a real hybrid cloud environment and performed a series of experiments. Our theoretical simulations and experimental results show that IAMR can guarantee a very low job error rate, while maintaining a moderate performance overhead. To address the algorithmic confidentiality problem, we focus on the program control flow and propose the Confidentiality Assurance MapReduce (CAMR) framework. CAMR performs the Runtime Control Flow Obfuscation (RCFO) technique to protect the predicates of MapReduce jobs. We implemented a prototype system for a real hybrid cloud environment. The security analysis and experimental results show that CAMR defeats static analysis-based reverse engineering attacks, raises the bar for the dynamic analysis-based reverse engineering attacks, and incurs a modest performance overhead.

Technology enables progress for individuals and organisations; however, adopting technology may not always be simple. Cloud computing technology has revolutionised how one consumes IT. Governments too can leverage the advantages of adopting cloud computing. A review of the literature reveals a gap in research on the adoption of cloud computing by the South African public sector. Limited research has been done on the topic of cloud computing and none of them are from a quantitative perspective. This study set out to answer the question, “What is the extent (current state, benefits, barriers and readiness levels) of the adoption of cloud computing by the South Africa public sector?” The study is of much value to the public sector of South Africa and other countries and organisations wanting to understand what to consider when adopting cloud computing. The study used a survey research strategy that was exploratory in nature. The sample comprised government CIO’s and government Senior IT management. Questionnaires were sent via a web link and 51 responses were completed. The results revealed that more than half of the South African public sector has adopted cloud computing; however there is a lack of visibility of government initiatives that promote cloud computing. The study shows that public organisations that have adopted cloud computing significantly perceive more benefits of cloud computing than organisations that are yet to adopt. The Technology Organisation Environment (TOE) framework tested the barriers to adoption, revealing areas of concern that are limiting successful cloud computing adoption and adoption rates. The study uncovers a timeline for further cloud computing adoption in the South African public sector.

We present an architecture for a fully decentralized peer-to-peer collaborative computing platform, offering services similar to Cloud Service Provider’s Platform-as-a-Service (PaaS) model, using volunteered resources rather than dedicated resources. This thesis is motivated by three research questions: (1) Is it possible to build a peer-to-peer col- laborative system using a fully decentralized infrastructure relying only on volunteered resources?, (2) How can light virtualization be used to mitigate the complexity inherent to the volunteered resources?, and (3) What are the minimal requirements for a computing platform similar to the PaaS cloud computing platform? We propose an architecture composed of three layers: the Network layer, the Virtual layer, and the Application layer. We also propose to use light virtualization technologies, or containers, to provide a uniform abstraction of the contributing resources and to isolate the host environment from the contributed environment. Then, we propose a minimal API specification for this computing platform, which is also applicable to PaaS computing platforms. The findings of this thesis corroborate the hypothesis that peer-to-peer collaborative systems can be used as a basis for developing volunteer cloud computing infrastructures. We outline the implications of using light virtualization as an integral virtualization primitive in public distributed computing platform. Finally, this thesis lays out a starting point for most volunteer cloud computing infrastructure development effort, because it circumscribes the essential requirements and presents solutions to mitigate the complexities inherent to this paradigm.

Data centres and other infrastructures in the field of information technology suffer from the major issue of ‘server sprawl’, a term used to depict the situation wherein a number of servers consume resources inefficiently, when compared to the business value of outcome obtained from them. Consolidation of servers, rather than dedicating whole servers to individual applications, optimizes the usage of hardware resources, and virtualization achieves this by allowing multiple servers to share a single hardware platform. Server virtualization is facilitated by the usage of hypervisors, among which Xen is widely preferred because of its dual virtualization modes, virtual machine migration support and scalability. This research work involves an analysis of the CPU scheduling algorithms incorporated into Xen, on the basis of the algorithm’s performance in different workload scenarios. In addition to performance evaluation, the results obtained lay emphasis on the importance of compute intensive or I/O intensive domain handling capacity of a hypervisor’s CPU scheduling algorithm in virtualized server environments. Based on this knowledge, the selection of CPU scheduler in a hypervisor can be aligned with the requirements of the hosted applications. A new credit-based VCPU scheduling scheme is proposed, in which the credits remaining for each VCPU after every accounting period plays a significant role in the scheduling decision. The proposed scheduling strategy allows those VCPUs of I/O intensive domains to supersede others, in order to favour the reduction of I/O bound domain response times and the subsequent bottleneck in the CPU run queue. Though a small percentage of context switch overhead is introduced, the results indicate substantial improvement of I/O handling and fairness in re-source allocation between the host and guest domains.

In multi-view video applications, view synthesis is a computationally intensive task that needs to be done correctly and efficiently in order to deliver a seamless user experience. In order to provide fast and efficient view synthesis, in this thesis, we present a cloud-based implementation that will be especially beneficial to mobile users whose devices may not be powerful enough for high quality view synthesis. Our proposed implementation balances the view synthesis algorithm’s components across multiple threads and utilizes the computational capacity of modern CPUs for faster and higher quality view synthesis. For arbitrary view generation, we utilize the depth map of the scene from the cameras’ viewpoint and estimate the depth information conceived from the virtual camera. The estimated depth is then used in a backward direction to warp the cameras’ image onto the virtual view. Finally, we use a depth-aided inpainting strategy for the rendering step to reduce the effect of disocclusion regions (holes) and to paint the missing pixels. For our cloud implementation, we employed an automatic scaling feature to offer elasticity in order to adapt the service load according to the fluctuating user demands. Our performance results using 4 multi-view videos over 2 different scenarios show that our proposed system achieves average improvement of 3x speedup, 87% efficiency, and 90% CPU utilization for the parallelizable parts of the algorithm.

Handheld devices are becoming increasingly common, and they have varied range of resources. Mobile Cloud Computing (MCC) allows resource constrained devices to offload computation and use storage capacities of more resourceful surrogate machines. This enables creation of new and interesting applications for all devices. We propose a scheme that constructs a high-performance de-centralized system by a group of volunteer mobile devices which come together to form a resourceful unit (cloudlet). The idea is to design a model to operate as a public-resource between mobile devices in close geographical proximity. This cloudlet can provide larger storage capability and can be used as a computational resource by other devices in the network. The system needs to watch the movement of the participating nodes and restructure the topology if some nodes that are providing support to the cloudlet fail or move out of the network. In this work, we discuss the need of the system, our goals and design issues in building a scalable and reconfigurable system. We achieve this by leveraging the concept of virtual dominating set to create an overlay in the broads of the network and distribute the responsibilities in hosting a cloudlet server. We propose an architecture for such a system and develop algorithms that are requited for its operation. We map the resources available in the network by first scoring each device individually, and then gathering these scores to determine suitable candidate cloudlet nodes. We have simulated cloudlet functionalities for several scenarios and show that our approach is viable alternative for many applications such as sharing GPS, crowd sourcing, natural language processing, etc.