172 research outputs found

    An Analytical Survey of Provenance Sanitization

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    Security is likely becoming a critical factor in the future adoption of provenance technology, because of the risk of inadvertent disclosure of sensitive information. In this survey paper we review the state of the art in secure provenance, considering mechanisms for controlling access, and the extent to which these mechanisms preserve provenance integrity. We examine seven systems or approaches, comparing features and identifying areas for future work.Comment: To appear, IPAW 201

    An Access Control Model for Protecting Provenance Graphs

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    A template-based graph transformation system for the PROV data model

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    As data provenance becomes a significant metadata in validating the origin of information and asserting its quality, it is crucial to hide the sensitive information of provenance data to enable trustworthiness prior to sharing provenance in open environments such as the Web. In this paper, a graph rewriting system is constructed from the PROV data model to hide restricted provenance information while preserving the integrity and connectivity of the provenance graph. The system is formally established as a template-based framework and formalised using category theory concepts, such as functors, diagrams, and natural transformation

    Food Quality Strategies for enhancing organic food quality

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    This Research Topic Review aims to summarise the available knowledge on strategies for enhancing organic food quality. The Review will provide organic advisers with a better understanding of the differences between organic and conventional food quality so that they can support the development of organic farming systems and supply chains that deliver better quality organic food. The Review takes a broad definition of food quality and on the appropriate methods for determining food quality. However, the focus is on the factors that are more or less within the control of the farmer and the rest of the supply chain, and that directly impact on the appreciation or the intrinsic quality of the food as presented to, and eaten by the consumer. The specific issues addressed by the Review include: • Consumer perceptions of organic food qualities and the market for organic food • Organic supply chains and their impact on quality, in the broadest sense • Environmental quality of systems – although not an intrinsic quality (in the same way as, for example, the vitamin content of food), it is an important quality parameter for organic food • Food safety • Crop products – production systems and quality • Livestock products – production systems and quality Twenty three Defra funded research projects are reviewed and a total of 355 papers selected from the Orgprints archive (www.orgprints.org) using the search term “organic food quality” have been scanned. Thirty one have been selected for review. Several additional sources have also been identified. In total, 75 sources have been reviewed

    Survey: Leakage and Privacy at Inference Time

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    Leakage of data from publicly available Machine Learning (ML) models is an area of growing significance as commercial and government applications of ML can draw on multiple sources of data, potentially including users' and clients' sensitive data. We provide a comprehensive survey of contemporary advances on several fronts, covering involuntary data leakage which is natural to ML models, potential malevolent leakage which is caused by privacy attacks, and currently available defence mechanisms. We focus on inference-time leakage, as the most likely scenario for publicly available models. We first discuss what leakage is in the context of different data, tasks, and model architectures. We then propose a taxonomy across involuntary and malevolent leakage, available defences, followed by the currently available assessment metrics and applications. We conclude with outstanding challenges and open questions, outlining some promising directions for future research

    Trading Indistinguishability-based Privacy and Utility of Complex Data

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    The collection and processing of complex data, like structured data or infinite streams, facilitates novel applications. At the same time, it raises privacy requirements by the data owners. Consequently, data administrators use privacy-enhancing technologies (PETs) to sanitize the data, that are frequently based on indistinguishability-based privacy definitions. Upon engineering PETs, a well-known challenge is the privacy-utility trade-off. Although literature is aware of a couple of trade-offs, there are still combinations of involved entities, privacy definition, type of data and application, in which we miss valuable trade-offs. In this thesis, for two important groups of applications processing complex data, we study (a) which indistinguishability-based privacy and utility requirements are relevant, (b) whether existing PETs solve the trade-off sufficiently, and (c) propose novel PETs extending the state-of-the-art substantially in terms of methodology, as well as achieved privacy or utility. Overall, we provide four contributions divided into two parts. In the first part, we study applications that analyze structured data with distance-based mining algorithms. We reveal that an essential utility requirement is the preservation of the pair-wise distances of the data items. Consequently, we propose distance-preserving encryption (DPE), together with a general procedure to engineer respective PETs by leveraging existing encryption schemes. As proof of concept, we apply it to SQL log mining, useful for database performance tuning. In the second part, we study applications that monitor query results over infinite streams. To this end, -event differential privacy is state-of-the-art. Here, PETs use mechanisms that typically add noise to query results. First, we study state-of-the-art mechanisms with respect to the utility they provide. Conducting the so far largest benchmark that fulfills requirements derived from limitations of prior experimental studies, we contribute new insights into the strengths and weaknesses of existing mechanisms. One of the most unexpected, yet explainable result, is a baseline supremacy. It states that one of the two baseline mechanisms delivers high or even the best utility. A natural follow-up question is whether baseline mechanisms already provide reasonable utility. So, second, we perform a case study from the area of electricity grid monitoring revealing two results. First, achieving reasonable utility is only possible under weak privacy requirements. Second, the utility measured with application-specific utility metrics decreases faster than the sanitization error, that is used as utility metric in most studies, suggests. As a third contribution, we propose a novel differential privacy-based privacy definition called Swellfish privacy. It allows tuning utility beyond incremental -event mechanism design by supporting time-dependent privacy requirements. Formally, as well as by experiments, we prove that it increases utility significantly. In total, our thesis contributes substantially to the research field, and reveals directions for future research

    Applications of Genomics in Regulatory Food Safety Testing in Canada

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    Recent developments in the field of pathogen genomics herald a new paradigm for analytical food microbiology in which pathogenic bacteria will be characterized on the basis of their genetic profile rather than traditional approaches relying on phenotypic properties. The ability to identify gene markers associated with virulence, antimicrobial resistance, and other properties relevant to the identification, risk profiling, and typing of foodborne bacterial isolates will play a critical role in informing regulatory decisions and tracing sources of food contamination. Here we present several scenarios illustrating current and prospective roles for pathogen genomics in food inspection

    Big Data Processing Attribute Based Access Control Security

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    The purpose of this research is to analyze the security of next-generation big data processing (BDP) and examine the feasibility of applying advanced security features to meet the needs of modern multi-tenant, multi-level data analysis. The research methodology was to survey of the status of security mechanisms in BDP systems and identify areas that require further improvement. Access control (AC) security services were identified as priority area, specifically Attribute Based Access Control (ABAC). The exemplar BDP system analyzed is the Apache Hadoop ecosystem. We created data generation software, analysis programs, and posted the detailed the experiment configuration on GitHub. Overall, our research indicates that before a BDP system, such as Hadoop, can be used in operational environment significant security configurations are required. We believe that the tools are available to achieve a secure system, with ABAC, using Apache Ranger and Apache Atlas. However, these systems are immature and require verification by an independent third party. We identified the following specific actions for overall improvement: consistent provisioning of security services through a data analyst workstation, a common backplane of security services, and a management console. These areas are partially satisfied in the current Hadoop ecosystem, continued AC improvements through the open source community, and rigorous independent testing should further address remaining security challenges. Robust security will enable further use of distributed, cluster BDP, such as Apache Hadoop and Hadoop-like systems, to meet future government and business requirements
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