近年雲存儲發展迅速，它具彈性的收費模式還有使用上的便利性吸引了不少用家把它當作一個備份的平台，如何保障雲端上資料的完整性也就成了一項重要的課題。我們試著探討如何能有效地在客戶端檢查雲端上資料的完整性，並且在探測到雲存儲節點故障以後如何有效地進行修復。抹除碼(Erasure codes)透過產生冗餘，令編碼過後的資料能允許一定程度的缺片。雲端使用者可以利用抹除碼把檔案分散到不同的雲節點，即使其中一些節點壞了用戶還是能透過解碼餘下的資料來得出原檔。我們的研究是基於一種叫再造編碼(Regenerating code)的新興抹除碼。再造編碼借用了網絡編碼(Network coding)的概念，使得在修復錯誤節點的時候並不需要把完整的原檔先重構一遍，相比起一些傳統的抹除碼（如里德所羅門碼Reed-Solomoncode）能減少修復節點時需要下載的資料量。其中我們在FMSR這門再造編碼上實現了一個能有效檢測錯誤的系統FMSR-DIP。FMSR-DIP的好處是在檢測的時候只需要下載一小部份的資料，而且不要求節點有任何的編碼能力，可以直接對應現今的雲存儲。為了驗證我們系統的實用性，我們在雲存儲的測試平台上運行了一系列的測試。 / To protect outsourced data in cloud storage against corruptions, enabling integrity protection, fault tolerance, and efficient recovery for cloud storage becomes critical. To enable fault tolerance from a client-side perspective, users can encode their data with an erasure code and stripe the encoded data across different cloud storage nodes. We base our work on regenerating codes, a recently proposed type of erasure code that borrows the concept of network coding and requires less repair traffic than traditional erasure codes during failure recovery. We study the problem of remotely checking the integrity of regenerating-coded data against corruptions under a real-life cloud storage setting. Specifically, we design a practical data integrity protection (DIP) scheme for a specific regenerating code, while preserving the intrinsic properties of fault tolerance and repair traffic saving. Our DIP scheme is designed under the Byzantine adversarial model, and enables a client to feasibly verify the integrity of random subsets of outsourced data against general or malicious corruptions. It works under the simple assumption of thin-cloud storage and allows different parameters to be fine-tuned for the performance-security trade-off. We implement and evaluate the overhead of our DIP scheme in a cloud storage testbed under different parameter choices. We demonstrate that remote integrity checking can be feasibly integrated into regenerating codes in practical deployment. / Detailed summary in vernacular field only. / Chen, Chuk Hin Henry. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 38-41). / Abstracts also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Preliminaries --- p.4 / Chapter 2.1 --- FMSR Implementation --- p.4 / Chapter 2.2 --- Threat Model --- p.6 / Chapter 2.3 --- Cryptographic Primitives --- p.7 / Chapter 3 --- Design --- p.8 / Chapter 3.1 --- Design Goals --- p.8 / Chapter 3.2 --- Notation --- p.9 / Chapter 3.3 --- Overview of FMSR-DIP --- p.11 / Chapter 3.4 --- Basic Operations --- p.11 / Chapter 3.4.1 --- Upload operation --- p.11 / Chapter 3.4.2 --- Check operation --- p.13 / Chapter 3.4.3 --- Download operation --- p.15 / Chapter 3.4.4 --- Repair operation --- p.16 / Chapter 4 --- Implementation --- p.17 / Chapter 4.1 --- Integration of DIP into NCCloud --- p.17 / Chapter 4.2 --- Instantiating Cryptographic Primitives --- p.18 / Chapter 4.3 --- Trade-off Parameters --- p.19 / Chapter 5 --- Security Analysis --- p.22 / Chapter 5.1 --- Uses of Security Primitives --- p.22 / Chapter 5.2 --- Security Guarantees --- p.23 / Chapter 5.2.1 --- Corrupting an AECC Stripe --- p.23 / Chapter 5.2.2 --- Picking Corrupted Bytes for Checking --- p.25 / Chapter 5.2.3 --- Putting It All Together --- p.26 / Chapter 6 --- Evaluations --- p.27 / Chapter 6.1 --- Running Time Analysis --- p.27 / Chapter 6.2 --- Monetary Cost Analysis --- p.30 / Chapter 6.3 --- Summary --- p.33 / Chapter 7 --- Related Work --- p.34 / Chapter 8 --- Conclusions --- p.37 / Bibliography --- p.38

Cloud computing is one of the most promising technologies for backup and data storage that provides flexible access to data. Cloud computing plays a vital role in remote backup. It is so unfortunate that this computing technique has flaws that thrilled and edgy end users in implementing it effectively. These flaws include factors like lack of integrity, confidentiality and privacy to information. A secure cloud is impossible unless the computer-generated environment is appropriately secured. In any form of technology it is always advisable that security challenges must be prior identified and fixed before the implementation of that particular technology. Primarily, this study will focus on finding security issues in cloud computing with the objective of finding concerns like credential theft and session management in the ―Cloud‖. Main arguments like HTTP banner disclosure, Bash ―ShellShock‖ Injection and password issues were discovered during the stages of study implementation. These challenges may provide information that will permit hackers in manipulating and exploiting cloud environment. Identifying credential theft and session management in cloud-based file sharing technologies a mixed method approach was implemented throughout the course of the study due to the nature of study and unity of analysis. Penetration tests were performed as security testing technique. Prevention and guideline of security threats leads to a friendly and authentic world of technology.

Tang, Yang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 60-65). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Policy-based File Assured Deletion --- p.7 / Chapter 2.1 --- Background --- p.7 / Chapter 2.2 --- Policy-based Deletion --- p.9 / Chapter 3 --- Basic Design of FADE --- p.13 / Chapter 3.1 --- Entities --- p.13 / Chapter 3.2 --- Deployment --- p.15 / Chapter 3.3 --- "Security Goals, Threat Models, and Assumptions" --- p.16 / Chapter 3.4 --- The Basics - File Upload/Download --- p.18 / Chapter 3.5 --- Policy Revocation for File Assured Deletion --- p.23 / Chapter 3.6 --- Multiple Policies --- p.23 / Chapter 3.7 --- Policy Renewal --- p.25 / Chapter 4 --- Extensions of FADE --- p.27 / Chapter 4.1 --- Access Control with ABE --- p.27 / Chapter 4.2 --- Multiple Key Managers --- p.31 / Chapter 5 --- Implementation --- p.35 / Chapter 5.1 --- Representation of Metadata --- p.36 / Chapter 5.2 --- Client --- p.37 / Chapter 5.3 --- Key Managers --- p.38 / Chapter 6 --- Evaluation --- p.40 / Chapter 6.1 --- Experimental Results on Time Performance of FADE --- p.41 / Chapter 6.1.1 --- Evaluation of Basic Design --- p.42 / Chapter 6.1.2 --- Evaluation of Extensions --- p.46 / Chapter 6.2 --- Space Utilization of FADE --- p.49 / Chapter 6.3 --- Cost Model --- p.51 / Chapter 6.4 --- Lessons Learned --- p.53 / Chapter 7 --- Related Work --- p.54 / Chapter 8 --- Conclusions --- p.58 / Bibliography --- p.60

Software systems increasingly interact with each other, forming ecosystems. Cloud is one such ecosystem that has evolved and enabled other technologies like IoT and containers. Such systems are very complex and heterogeneous because their components can have diverse origins, functions, security policies, and communication protocols, which makes it difficult to comprehend, utilize and consequently secure them. Abstract architectural models can be used to handle this complexity and heterogeneity but there is lack of work on precise, implementation/vendor neutral and holistic models which represent ecosystem components and their mutual interactions. We attempted to find similarities in systems and generalize to create abstract models for adding security. We represented the ecosystem as a Reference architecture (RA) and the ecosystem units as patterns. We started with a pattern diagram which showed all the components involved along with their mutual interactions and dependencies. We added components to the already existent Cloud security RA (SRA). Containers, being relatively new virtualization technology, did not have a precise and holistic reference architecture. We have built a partial RA for containers by identifying and modeling components of the ecosystem. Container security issues were identified from the literature as well as analysis of our patterns. We added corresponding security countermeasures to container RA as security patterns to build a container SRA. Finally, using container SRA as an example, we demonstrated an approach for RA validation. We have also built a composite pattern for fog computing that is an intermediate platform between Cloud and IoT devices. We represented an attack, Distributed Denial of Service (DDoS) using IoT devices, in the form of a misuse pattern which explains it from the attacker’s perspective. We found this modelbased approach useful to build RAs in a flexible and incremental way as components can be identified and added as the ecosystems expand. This provided us better insight to analyze security issues across boundaries of individual ecosystems. A unified, precise and holistic view of the system is not just useful for adding or evaluating security, this approach can also be used to ensure compliance, privacy, safety, reliability and/or governance for cloud and related ecosystems. This is the first work we know of where patterns and RAs are used to represent ecosystems and analyze their security. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

Cloud Computing has advanced to the point where it may be considered an attractive proposition for an increasing number of South African organisations, yet the adoption of Cloud Computing in South Africa remains relatively low. Many organisations have been hesitant to adopt Cloud solutions owing to a variety of inhibiting factors and concerns that have created mistrust in Cloud Computing. One of the top concerns identified is security within the Cloud Computing environment. The approaching commencement of new data protection legislation in South Africa, known as the Protection of Personal Information Act (POPI), may provide an ideal opportunity to address the information security-related inhibiting factors and foster a trust relationship between potential Cloud users and Cloud providers. POPI applies to anyone who processes personal information and regulates how they must handle, store and secure that information. POPI is considered to be beneficial to Cloud providers as it gives them the opportunity to build trust with potential Cloud users through achieving compliance and providing assurance. The aim of this dissertation is, therefore, to develop a framework for Cloud Computing adoption that will assist in mitigating the information security-related factors inhibiting Cloud adoption by fostering a trust relationship through compliance with the POPI Act. It is believed that such a framework would be useful to South African Cloud providers and could ultimately assist in the promotion of Cloud adoption in South Africa.

Traditionally, health records have been stored in paper folders at the physician’s consulting rooms – or at the patient’s home. Some people stored the health records of their family members, so as to keep a running history of all the medical procedures they went through, and what medications they were given by different physicians at different stages of their lives. Technology has introduced better and safer ways of storing these records, namely, through the use of Personal Health Records (PHRs). With time, different types of PHRs have emerged, i.e. local, remote server-based, and hybrid PHRs. Web-based PHRs fall under the remote server-based PHRs; and recently, a new market in storing PHRs has emerged. Cloud computing has become a trend in storing PHRs in a more accessible and efficient manner. Despite its many benefits, cloud computing has many privacy and security concerns. As a result, the adoption rate of cloud services is not yet very high. A qualitative and exploratory research design approach was followed in this study, in order to reach the objective of proposing guidelines that could assist PHR providers in selecting a secure Cloud Service Provider (CSP) to store their customers’ health data. The research methods that were used include a literature review, systematic literature review, qualitative content analysis, reasoning, argumentation and elite interviews. A systematic literature review and qualitative content analysis were conducted to examine those risks in the cloud environment that could have a negative impact on the secure storing of PHRs. PHRs must satisfy certain dimensions, in order for them to be meaningful for use. While these were highlighted in the research, it also emerged that certain risks affect the PHR dimensions directly, thus threatening the meaningfulness and usability of cloud-based PHRs. The literature review revealed that specific control measures can be adopted to mitigate the identified risks. These control measures form part of the material used in this study to identify the guidelines for secure cloud-based PHRs. The guidelines were formulated through the use of reasoning and argumentation. After the guidelines were formulated, elite interviews were conducted, in order to validate and finalize the main research output: i.e. guidelines. The results of this study may alert PHR providers to the risks that exist in the cloud environment; so that they can make informed decisions when choosing a CSP for storing their customers’ health data.

Cloud computing is a relatively immature computing paradigm that could significantly benefit users. Cloud computing solutions are often associated with potential benefits such as cost reduction, less administrative hassle, flexibility and scalability. For organisations to realize such potential benefits, cloud computing solutions need to be chosen, implemented, managed and governed in a way that is secure, compliant with internal and external requirements and indicative of due diligence. This can be a challenge, given the many concerns and risks commonly associated with cloud computing solutions. One cloud computing solution that is being widely adopted around the world is cloud-based email. One of the foremost adopters of this cloud computing solution is higher education institutions. These higher education institutions stand to benefit greatly from using such services. Cloud-based email can be provisioned to staff and students at these institutions for free. Additionally, cloud service providers (CSPs) are able to provide a better email service than some higher education institutions would be able to provide if they were required to do so in-house. CSPs often provide larger inboxes and many extra services with cloud-based email. Cloud-based email is, therefore, clearly an example of a cloud computing solution that has the potential to benefit organisations. There are however, risks and challenges associated with the use of this cloud computing solution. Two of these challenges relate to ensuring conformance to internal and external (legal, regulatory and contractual obligations) requirements and to providing a mechanism of assuring that cloud-based email related activities are sound. The lack of structured guidelines for assuring the conformance of cloud-based email is putting this service at risk at higher education institutions in South Africa. This work addresses this problem by promoting a best practice based approach to assuring the conformance of cloud-based email at higher education institutions. To accomplish this, components of applicable standards and best practice guidelines for IT governance, IT assurance and IT conformance are used to construct a framework for assuring the conformance of cloud-based email. The framework is designed and verified using sound design science principles. The utility and value of the framework has been demonstrated at a higher education institution in South Africa. This framework can be used to assist higher education institutions to demonstrate due diligence in assuring that they conform to legal and best practice requirements for the management and governance of cloud-based email. This is a significant contribution in the relatively new field of cloud computing governance.

Thesis (MComm)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The growing popularity and continuing development of cloud computing services is ever evolving and is slowly being integrated into our daily lives through our interactions with electronic devices. Cloud Computing has been heralded as the solution for enterprises to reduce information technology infrastructure cost by buying cloud services as a utility. While this premise is generally correct, in certain industries for example banking, the sensitive nature of the information submitted to the cloud for storage or processing places information security responsibilities on the party using the cloud services as well as the party providing them. Problems associated with cloud computing are loss of control, lack of trust between the contracting parties in the cloud relationship (customer and cloud service provider) and segregating data securely in the virtual environment. The risk and responsibilities associated with data loss was previously mainly reputational in nature but with the promulgation and signing by the South African Parliament of the Protection of Personal Information Bill (POPI) in August 2013 these responsibilities to protect information are in the process to be legislated in South Africa. The impact of the new legislation on the cloud computing environment needs to be investigated as the requirements imposed by the Bill might render the use of cloud computing in regard to sensitive data nonviable without replacing some of the IT infrastructure cost benefits that cloud computing allows with increased data security costs. In order to investigate the impact of the new POPI legislation on cloud computing, the components and characteristics of the cloud will be studied and differentiated from other forms of computing. The characteristics of cloud computing are the unique identifiers that differentiate it from Grid and Cluster computing. The component study is focused on the service and deployment models that can be associated with cloud computing. The understanding obtained will be used to compile a new definition of cloud computing. By utilizing the cloud definition of what components and processes constitute cloud computing the different types of data security processes and technical security measures can be implemented are studied. This will include information management and governance policies as well as technical security measures such as encryption and virtualisation security. The last part of the study will be focussed on the Bill and the legislated requirements and how these can be complied with using the security processes identified in the rest of the study. The new legislation still has to be signed by the State President after which businesses will have one year to comply and due to the short grace period businesses need to align their business practices with the proposed requirements. The impact is wide ranging from implementing technical information security processes to possible re-drafting of service level agreements with business partners that share sensitive information. The study will highlight the major areas where the Bill will impact businesses as well as identifying possible solutions that could be implemented by cloud computing users when storing or processing data in the cloud. / AFRIKAANSE OPSOMMING: Die groei in gewildheid en die ontwikkeling van wolkbewerking dienste is besig om te verander en is stadig besig om in ons daaglikse lewens geintegreer te word deur ons interaksie met elektroniese toestelle. Wolkbewerking word voorgehou as ‘n oplossing vir besighede om hul inligtings tegnologie infrastruktuur kostes te verminder deur dienste te koop soos hulle dit benodig. Alhoewel die stelling algemeen as korrek aanvaar word, kan spesifieke industrië soos byvoorbeeld die bankwese se inligting so sensitief wees dat om die inligting aan wolkbewerking bloot te stel vir berging en prosesseering dat addisionele verantwoodelikhede geplaas op die verantwoordelike partye wat die wolk dienste gebruik sowel as die persone wat dit voorsien. Probleme geassosieër met wolk- bewerking is die verlies aan beheer, gebrekkige vertroue tussen kontakteurende partye in die wolk verhouding (verbruiker en wolk dienste verskaffer) en die beveiliging van verdeelde inligting in die virtuele omgewing. Die risiko’s en verantwoordelikhede geassosieër met inligtings verlies was voorheen grootliks gebasseer op die skade wat aan die besigheid se reputasie aangedoen kan word, maar met die publiseering en ondertekening deur die Suid-Afrikaans Parliament van die Beskerming van Persoonlike Inligting Wet (BVPI) in Augustus 2013 is hierdie verantwoordelikhede in die proses om in wetgewing in Suid Afrika vas gelê te word. Die impak van die nuwe wetgewing op die wolkbewering omgewing moet ondersoek word omdat die vereistes van die Wet die gebruik van wolkbewerking in terme van sensitiewe inligting so kan beinvloed dat dit nie die moeite werd kan wees om te gebruik nie, en veroorsaak dat addisionele verminderde IT infrastruktuur koste voordele vervang moet word met addisionele inligting beveiligings kostes. Om die impak van die nuwe BVPI wetgewing op wolkbewerking te ondersoek moet die komponente en karakter eienskappe van die wolk ondersoek word om vas te stel wat dit uniek maak van ander tipes rekenaar bewerking. Die karakter eienskappe van wolkbewerking is die unieke aspekte wat dit apart identifiseer van Rooster en Groep rekenaar bewerking. Die komponente studie sal fokus op die dienste en implimenterings modelle wat geassosieer word met wolkbewerking. Die verstandhouding wat deur voorsafgaande studie verkry is sal dan gebruik word om ‘n nuwe definisie vir wolkbewerking op te stel. Deur nou van die definisie gebruik te maak kan die inligtings sekuriteit prosesse en tegniese sekuriteits maatreëls wat deur die verantwoordelike party en die wolkbewerkings dienste verskaffer gebruik kan word om die komponente en prosesse te beveilig bestudeer word. Die studie sal insluit, inligtings bestuur prosesse en korporatiewe bestuur asook tegniese beveiligings maatreels soos kodering en virtualisasie sekuriteit. Die laaste deel van die studie sal fokus op die BVPI wetgewing en die vereistes en hoe om daaraan te voldoen deur die sekuritiets maatreëls geidentifiseer in die res van die studie te implimenteer. Die nuwe wetgewing moet nog deur die Staats President onderteken word waarna besighede ‘n jaar sal he om aan die vereistes te voldoen en omdat die periode so kort is moet besighede hulself voorberei en besigheid prosesse aanpas. Die impak van die wetgewing strek baie wyd en beinvloed van tegnise inligtings beveiligings prosesse tot kontrakte aangaande diens lewering wat dalk oor opgestel moet word tussen partye wat sensitiewe inligting uitruil. Die studie sal die prominente areas van impak uitlig asook die moontlike oplossings wat gebruik kan word deur partye wat wolkbewerking gebruik om inligting te stoor of te bewerk.

雲存儲是一個新興的服務模式，讓個人和企業的數據備份外包予較低成本的遠程雲服務提供商。本論文提出的方法，以確保數據的安全性和雲備份系統的可靠性。 / 在本論文的第一部分，我們提出 FadeVersion，安全的雲備份作為今天的雲存儲服務上的安全層服務的系統。 FadeVersion實現標準的版本控制備份設計，從而消除跨不同版本備份的冗餘數據存儲。此外，FadeVersion在此設計上加入了加密技術以保護備份。具體來說，它實現細粒度安全删除，那就是，雲客戶可以穩妥地在雲上删除特定的備份版本或文件，使有關文件永久無法被解讀，而其它共用被删除數據的備份版本或文件將不受影響。我們實現了試驗性原型的 FadeVersion並在亞馬遜S3之上進行實證評價。我們證明了，相對於不支援度安全删除技術傳統的雲備份服務 FadeVersion只增加小量額外開鎖。 / 在本論文的第二部分，提出 CFTDedup一個分佈式代理系統，利用通過重複數據删除增加雲存儲的效率，而同時確保代理之間的崩潰容錯。代理之間會進行同步以保持重複數據删除元數據的一致性。另外，它也分批更新元數據減輕同步帶來的開銷。我們實現了初步的原型CFTDedup並通過試驗台試驗，以存儲虛擬機映像評估其重複數據删除的運行性能。我們還討論了幾個開放問題，例如如何提供可靠、高性能的重複數據删除的存儲。我們的CFTDedup原型提供了一個平台來探討這些問題。 / Cloud storage is an emerging service model that enables individuals and enterprises to outsource the storage of data backups to remote cloud providers at a low cost. This thesis presents methods to ensure the data security and reliability of cloud backup systems. / In the first part of this thesis, we present FadeVersion, a secure cloud backup system that serves as a security layer on top of todays cloud storage services. FadeVersion follows the standard version-controlled backup design, which eliminates the storage of redundant data across different versions of backups. On top of this, FadeVersion applies cryptographic protection to data backups. Specifically, it enables ne-grained assured deletion, that is, cloud clients can assuredly delete particular backup versions or files on the cloud and make them permanently in accessible to anyone, while other versions that share the common data of the deleted versions or les will remain unaffected. We implement a proof-of-concept prototype of FadeVersion and conduct empirical evaluation atop Amazon S3. We show that FadeVersion only adds minimal performance overhead over a traditional cloud backup service that does not support assured deletion. / In the second part of this thesis, we present CFTDedup, a distributed proxy system designed for providing storage efficiency via deduplication in cloud storage, while ensuring crash fault tolerance among proxies. It synchronizes deduplication metadata among proxies to provide strong consistency. It also batches metadata updates to mitigate synchronization overhead. We implement a preliminary prototype of CFTDedup and evaluate via test bed experiments its runtime performance in deduplication storage for virtual machine images. We also discuss several open issues on how to provide reliable, high-performance deduplication storage. Our CFTDedup prototype provides a platform to explore such issues. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Rahumed, Arthur. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 47-51). / Abstracts also in Chinese. / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Cloud Based Backup and Assured Deletion --- p.1 / Chapter 1.2 --- Crash Fault Tolerance for Backup Systems with Deduplication --- p.4 / Chapter 1.3 --- Outline of Thesis --- p.6 / Chapter 2 --- Background and Related Work --- p.7 / Chapter 2.1 --- Deduplication --- p.7 / Chapter 2.2 --- Assured Deletion --- p.7 / Chapter 2.3 --- Policy Based Assured Deletion --- p.8 / Chapter 2.4 --- Convergent Encryption --- p.9 / Chapter 2.5 --- Cloud Based Backup Systems --- p.10 / Chapter 2.6 --- Fault Tolerant Deduplication Systems --- p.10 / Chapter 3 --- Design of FadeVersion --- p.12 / Chapter 3.1 --- Threat Model and Assumptions for Fade Version --- p.12 / Chapter 3.2 --- Motivation --- p.13 / Chapter 3.3 --- Main Idea --- p.14 / Chapter 3.4 --- Version Control --- p.14 / Chapter 3.5 --- Assured Deletion --- p.16 / Chapter 3.6 --- Assured Deletion for Multiple Policies --- p.18 / Chapter 3.7 --- Key Management --- p.19 / Chapter 4 --- Implementation of FadeVersion --- p.20 / Chapter 4.1 --- System Entities --- p.20 / Chapter 4.2 --- Metadata Format in FadeVersion --- p.22 / Chapter 5 --- Evaluation of FadeVersion --- p.24 / Chapter 5.1 --- Setup --- p.24 / Chapter 5.2 --- Backup/Restore Time --- p.26 / Chapter 5.3 --- Storage Space --- p.28 / Chapter 5.4 --- Monetary Cost --- p.29 / Chapter 5.5 --- Conclusions --- p.30 / Chapter 6 --- CFTDedup Design --- p.31 / Chapter 6.1 --- Failure Model --- p.31 / Chapter 6.2 --- System Overview --- p.32 / Chapter 6.3 --- Distributed Deduplication --- p.33 / Chapter 6.4 --- Crash Fault Tolerance --- p.35 / Chapter 6.5 --- Implementation --- p.36 / Chapter 7 --- Evaluation of CFTDedup --- p.37 / Chapter 7.1 --- Setup --- p.37 / Chapter 7.2 --- Experiment 1 (Archival) --- p.38 / Chapter 7.3 --- Experiment 2 (Restore) --- p.39 / Chapter 7.4 --- Experiment 3 (Recovery) --- p.40 / Chapter 7.5 --- Summary --- p.41 / Chapter 8 --- Future work and Conclusions of CFTDedup --- p.43 / Chapter 8.1 --- Future Work --- p.43 / Chapter 8.2 --- Conclusions --- p.44 / Chapter 9 --- Conclusion --- p.45 / Bibliography --- p.47

In recent years higher education institutions have come under increasing financial pressure. This has not only prompted universities to investigate more cost effective means of delivering course content and maintaining research output, but also to investigate the administrative functions that accompany them. As such, many South African universities have either adopted or are in the process of adopting some form of cloud computing given the recent drop in bandwidth costs. However, this adoption process has raised concerns about the security of cloud-based information and this has, in some cases, had a negative impact on the adoption process. In an effort to study these concerns many researchers have employed a positivist approach with little, if any, focus on the operational context of these universities. Moreover, there has been very little research, specifically within the South African context. This study addresses some of these concerns by investigating the threats and security incident response life cycle within a higher education cloud. This was done by initially conducting a small scale survey and a detailed thematic analysis of twelve interviews from three South African universities. The identified themes and their corresponding analyses and interpretation contribute on both a practical and theoretical level with the practical contributions relating to a set of security driven criteria for selecting cloud providers as well as recommendations for universities who have or are in the process of adopting cloud computing. Theoretically several conceptual frameworks are offered allowing the researcher to convey his understanding of how the aforementioned practical concepts relate to each other as well as the concepts that constitute the research questions of this study.