Outsourcing data services to the cloud is a nature fit for cloud usage. However, increasing security and privacy concerns from both enterprises and individuals on their outsourced data inhibit this trend. In this dissertation, we introduce service-centric solutions to address two types of security threats existing in the current cloud environments: semi-honest cloud providers and malicious cloud customers. Our solution aims not only to provide confidentiality and access controllability of outsourced data with strong cryptographic guarantee, but, more importantly, to fulfill specific security requirements from different cloud services with effective systematic ways. To provide strong cryptographic guarantee to outsourced data, we study the generic security problem caused by semi-honest cloud providers and introduce a novel proxy-based secure data outsourcing scheme. Specifically, our scheme improves the efficiency of traditional proxy re-encryption algorithm by integrating symmetric encryption and proxy re-encryption algorithms. With less computation cost on applying re-encryption operation directly on the encrypted data, our scheme allows flexible and efficient user revocation without revealing underlying data and heavy computation in the untrusted cloud. To address specific requirement from different cloud services, we investigate two specific cloud services: cloud-based content delivery service and cloud-based data processing service. For the former one, we focus on preserving cache property in the content delivery network and propose CloudSeal, a scheme for securely and flexibly sharing and distributing content via the public cloud. With the ability of caching the major part of a stored cipher content object in the delivery network for content distribution and keeping the minor part with the data owner for content authorization, CloudSeal achieves security and efficiency both theoretically and experimentally. For the later service, we design and realize CloudSafe, a framework that supports secure and efficient data processing with minimum key leakage in the vulnerable cloud virtualization environment. Through the adoption of one-time cryptographic key strategy and a centralized key management framework, CloudSafe efficiently avoids cross-VM side channel attack from malicious cloud customers in the cloud. Our experimental results confirm the practicality and scalability of CloudSafe. / Ph. D.

Through online activities, we produce a large amount of personal data traces every day. Many people acknowledge the significance of protecting personal data online but they might not act accordingly. This thesis project seeks to make these often hidden traces visible and thus understandable through a data physicalisation. This is to increase awareness and knowledge as well as spark reflection on how and if certain data should be protected. Six design activities with a focus on the active involvement of participants were conducted to create the concept of “OODOOLL”, a reversed voodoo doll that has the purpose of protecting users from any potential harm in relation to online activity and sparking reflection around the topic of data privacy. While some of the potentials of a data physicalisation, such as initiating conversations or increased levels of self-reflection, could be realised, there were several limitations to the concept, i.e. technical limitations or breaking down the complexity of aggregated data use. Especially in terms of the increased use of digital devices and the rise of emerging technologies, it is important for general users but also for interaction designers to be aware and have an understanding of data collection, data use and data protection.

Background. E-mail phishing is a type of social engineering where the threat actor sends e-mails with the intention to, for example, gain sensitive information or gain access to sensitive assets. Anyone can be a target of a phishing attempt, and any user that uses a digital environment should be aware of which factors to be attentive to in an e-mail. Objectives. This thesis intends to study the practical ability to identify phishing e-mails among users and what factors they are looking for when performing the classification. The intention is also to investigate if subjective knowledge impacts practical ability. Methods. A user study was conducted where the participants were to classify e-mails from an inbox as either phishing or legitimate. During the observation, the participants thought-out-loud for the authors of this thesis to hear their approach and which factors they noticed. A questionnaire also was conducted to capture the participants' knowledge, previous experience, and confidence in their classifications. Results. The results show that the majority of the participants did not know what factors to look after, nor how to inspect them, to make a justified classification of an e-mail. Most participants made the classifications based on their gut feelings. Those participants who had any theoretical knowledge showed more confidence and identified more phishing attempts. Conclusions. This thesis concluded that the participants lacked the required knowledge to identify phishing attempts. Further, it concludes that subjective knowledge leads to high confidence, which helps users make the correct classification. Therefore, this topic needs to be further enlightened to bring more awareness, and education needs to be conducted.

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The growing concerns in term of the privacy of data stored in public cloud have restrained the widespread adoption of cloud computing. The traditional method to protect the data privacy is to encrypt data before they are sent to public cloud, but heavy computation is always introduced by this approach, especially for the image and video data, which has much more amount of data than text data. Another way is to take advantage of hybrid cloud by separating the sensitive data from non-sensitive data and storing them in trusted private cloud and un-trusted public cloud respectively. But if we adopt the method directly, all the images and videos containing sensitive data have to be stored in private cloud, which makes this method meaningless. Moreover, the emergence of the Software-Defined Networking (SDN) paradigm, which decouples the control logic from the closed and proprietary implementations of traditional network devices, enables researchers and practitioners to design new innovative network functions and protocols in a much easier, flexible, and more powerful way. The data plane will ask the control plane to update flow rules when the data plane gets new network packets with which it does not know how to deal with, and the control plane will then dynamically deploy and configure flow rules according to the data plane's requests, which makes the whole network could be managed and controlled efficiently. However, this kind of reactive control model could be used by hackers launching Distributed Denial-of-Service (DDoS) attacks by sending large amount of new requests from the data plane to the control plane. For image data, we divide the image is into pieces with equal size to speed up the encryption process, and propose two kinds of method to cut the relationship between the edges. One is to add random noise in each piece, the other is to design a one-to-one mapping function for each piece to map different pixel value into different another one, which cuts off the relationship between pixels as well the edges. Our mapping function is given with a random parameter as inputs to make each piece could randomly choose different mapping. Finally, we shuffle the pieces with another random parameter, which makes the problems recovering the shuffled image to be NP-complete. For video data, we propose two different methods separately for intra frame, I-frame, and inter frame, P-frame, based on their different characteristic. A hybrid selective video encryption scheme for H.264/AVC based on Advanced Encryption Standard (AES) and video data themselves is proposed for I-frame. For each P-slice of P-frame, we only abstract small part of them in private cloud based on the characteristic of intra prediction mode, which efficiently prevents P-frame being decoded. For cloud running with SDN, we propose a framework to keep the controller away from DDoS attack. We first predict the amount of new requests for each switch periodically based on its previous information, and the new requests will be sent to controller if the predicted total amount of new requests is less than the threshold. Otherwise these requests will be directed to the security gate way to check if there is a attack among them. The requests that caused the dramatic decrease of entropy will be filter out by our algorithm, and the rules of these request will be made and sent to controller. The controller will send the rules to each switch to make them direct the flows matching with the rules to honey pot. / Computer and Information Science

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<p dir="ltr">Deep Neural Networks (DNNs) are deployed in many applications and protecting the privacy of training data has become a major concern. Membership Inference Attacks (MIAs) occur when an unauthorized person is able to determine whether a piece of data is used in training the DNNs. This paper investigates using Trusted Execution Environments (TEEs) in modern processors to protect the privacy of training data. Running DNNs on TEE, however, encounters many challenges, including limited computing and storage resources as well as a lack of development frameworks. This paper proposes a new method to partition pre-trained DNNs so that parts of the DNNs can fit into TEE to protect data privacy. The existing software infrastructure for running DNNs on TEE requires a significant amount of human effort using C programs. However, most existing DNNs are implemented using Python. This paper presents a framework that can automate most parts of the process of porting Python-based DNNs to TEE. The proposed method is deployed in Arm TrustZone-A on Raspberry Pi 3B+ with OPTEE-OS and evaluated on popular image classification models - AlexNet, ResNet, and VGG. Experimental results show that our method can reduce the accuracy of gradient-based MIAs on AlexNet, VGG- 16, and ResNet-20 evaluated on the CIFAR-100 dataset by 17.9%, 11%, and 35.3%. On average, processing an image in the native execution environment takes 4.3 seconds, whereas in the Trusted Execution Environment (TEE), it takes about 10.1 seconds per image.<br><br></p>

Yes / Digital health twins (DHTs) have been evolving with their diverse applications in medicine, specifically in older care settings, with the increasing demands of older adults. DHTs have already contributed to improving the quality of dementia and trauma care, cardiac treatment, and health care services for older individuals. Despite its many benefits, the optimum implementation of DHTs has faced several challenges associated with ethical issues, quality of care, management and leadership, and design considerations in older care settings. Since the need for such care is continuously rising and there is evident potential for DHTs to meet those needs, this review aims to map key concepts to address the gaps in the research knowledge to improve DHT implementation. The review aims to compile and synthesize the best available evidence regarding the problems encountered by older adults and care providers associated with the application of DHTs. The synthesis will collate the evidence of the issues associated with quality of care, the ethical implications of DHTs, and the strategies undertaken to overcome those challenges in older care settings. The review will follow the Joanna Briggs Institute (JBI) methodology. The published studies will be searched through CINAHL, MEDLINE, JBI, and Web of Science, and the unpublished studies through Mednar, Trove, OCLC WorldCat, and Dissertations and Theses. Studies published in English from 2002 will be considered. This review will include studies of older individuals (aged 65 years or older) undergoing care delivery associated with DHTs and their respective care providers. The concept will include the application of the technology, and the context will involve studies based on the older care setting. A broad scope of evidence, including quantitative, qualitative, text and opinion studies, will be considered. A total of 2 independent reviewers will screen the titles and abstracts and then review the full text. Data will be extracted from the included studies using a data extraction tool developed for this study. The results will be presented in a PRISMA-ScR (Preferred Reporting Items for Systematic Review and Meta-Analysis extension for Scoping Reviews) flow diagram. A draft charting table will be developed as a data extraction tool. The results will be presented as a "map" of the data in a logical, diagrammatic, or tabular form in a descriptive format. The evidence synthesis is expected to uncover the shreds of evidence required to address the ethical and care quality-related challenges associated with applying DHTs. A synthesis of various strategies used to overcome identified challenges will provide more prospects for adopting them elsewhere and create a resource allocation model for older individuals. DERR1-10.2196/51153. / A publishing grant has been received from Linnaeus University as part of the University Library’s research support.

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.

Diante dos recursos e avanços tecnológicos na área da saúde, a certificação digital vem ganhando espaço na área médica e odontológica, sendo utilizados e aplicados por clínicas de grande porte, hospitais, centros de saúde. Devido ao conhecimento público sobre as questões ética e legais que envolvem os cuidados com a saúde, os processos judiciais contra os cirurgiões-dentistas, aumentaram consideravelmente, e o seu único meio de prova é a correta e adequada confecção do prontuário odontológico e no caso do prontuário digital os cuidados e atenção devem ser redobrados. Para tanto, o presente estudo examinou os aspectos éticos e legais do prontuário odontológico digital perante a Justiça, relacionando a segurança, a privacidade e a validade jurídica enquanto meio de prova, nos termos do novo Código de Processo Civil, e a importância e aplicabilidade da certificação digital na Odontologia. A análise da literatura permitiu verificar que a certificação digital é realidade em outras áreas profissionais e está sendo cada vez mais aceita e aplicada como identidade pessoal dentro do ambiente virtual, garantindo integridade e inviolabilidade aos que se beneficiam desse tipo de segurança. Para que o prontuário digital possa ser considerado seguro, ele deve apresentar mecanismos capazes de assegurar autenticidade, confidencialidade e integridade dos documentos. Adicionalmente, deve ser digitalizado com emprego de certificado digital emitido no âmbito da Infraestrutura de Chaves Públicas Brasileiras. As tecnologias empregadas devem proteger os princípios e fundamentos do nosso ordenamento jurídico pátrio, bem como a dignidade humana dos indivíduos e sua intimidade, garantindo as ferramentas necessárias para a sua fiscalização. / Having in mind the massive information in advanced technology envolving health matters, the digital prontuaries happen to be more oftenlly used in Hospitals, Dental clinics and other health institutions. Due to the globalization, the cityzens themselves, developed more a know ledgement about their legal rigths, concerning dental and medical procedures. In the other hand, the health professionals have in their majority, only paper prontuaries, whitch can be easilly adulterated. The aim of this work is to analise the digital dental and medical prontuaries avaiable and determinate their security for both, patients and professionals, by the scope of the Justice and ethical matters. All the study was based on the \"New Brazilian Civil Law Code. The recall of the studyied literature, allowed us to verify that the digital certification, has been used to pervente any kind of frauds. In deed, this softwares have to be developed by informatic personel, but always following the Structured Brazilian Public Keys, in order to the rigths of the envolved parts can be assured.