Chenyun Dai

An Approach to Evaluate Data Trustworthiness Based on Data Provenance

Today, with the advances of information technology, individual people and organizations can obtain and process data from different sources. It is critical to ensure data integrity so that effective decisions can be made based on these data. An important component of any solution for assessing data integrity is represented by techniques and tools to evaluate the trustworthiness of data provenance. However, few efforts have been devoted to investigate approaches for assessing how trusted the data are, based in turn on an assessment of the data sources and intermediaries. To bridge this gap, we propose a data provenance trust model which takes into account various factors that may affect the trustworthiness and, based on these factors, assigns trust scores to both data and data providers. Such trust scores represent key information based on which data users may decide whether to use the data and for what purposes.

The Challenge of Assuring Data Trustworthiness

With the increased need of data sharing among multiple organizations, such as government organizations, financial corporations, medical hospitals and academic institutions, it is critical to ensure that data is trustworthy so that effective decisions can be made based on these data. In this paper, we first discuss motivations and requirement for data trustworthiness. We then present an architectural framework for a comprehensive system for trustworthiness assurance. We then discuss an important issue in our framework, that is, the evaluation of data provenance and survey a trust model for estimating the confidence level of the data and the trust level of data providers. By taking into account confidence about data provenance, we introduce an approach for policy observing query evaluation. We highlight open research issues and research directions throughout the paper.

Assessing the trustworthiness of location data based on provenance

Trustworthiness of location information about particular individuals is of particular interest in the areas of forensic science and epidemic control. In many cases, location information is not precise and may include fraudulent information. With the growth of mobile computing and positioning systems, e.g., GPS and cell phones, it has become possible to trace the location of moving objects. Such Systems provide us an opportunity to find out the true locations of individuals. In this paper, we present a model to compute trustworthiness of the location information of an individual based on different evidences from different sources. We also introduce a collusion attack that may bias the computation. Based on the analysis of the attack, we present the algorithm to detect and reduce the effect of collusion attacks. Our experimental results show the efficiency and effectiveness of our approach.

Query Processing Techniques for Compliance with Data Confidence Policies

Data integrity and quality is a very critical issue in many data-intensive decision-making applications. In such applications, decision makers need to be provided with high quality data on which they can rely on with high confidence. A key issue is that obtaining high quality data may be very expensive. We thus need flexible solutions to the problem of data integrity and quality. This paper proposes one such solution based on four key elements. The first element is the association of a confidence value with each data item in the database. The second element is the computation of the confidence values of query results by using lineage propagation. The third element is the notion of confidence policies. Such a policy restricts access to the query results by specifying the minimum confidence level that is required for use in a certain task by a certain subject. The fourth element is an approach to dynamically increment the data confidence level to return query results that satisfy the stated confidence policies. In particular, we propose several algorithms for incrementing the data confidence level while minimizing the additional cost. Our experimental results have demonstrated the efficiency and effectiveness of our approach.

Privacy-Preserving Assessment of Social Network Data Trustworthiness

Extracting useful knowledge from social network datasets is a challenging problem. To add to the difficulty of this problem, privacy concerns that exist for many social network datasets have restricted the ability to analyze these networks and consequently to maximize the knowledge that can be extracted from them. This paper addresses this issue by introducing the problem of data trustworthiness in social networks when repositories of anonymized social networks exist that can be used to assess such trustworthiness. Three trust score computation models (absolute, relative, and weighted) that can be instantiated for specific anonymization models are defined and algorithms to calculate these trust scores are developed. Using both real and synthetic social networks, the usefulness of the trust score computation is validated through a series of experiments.

Privacy-preserving assessment of location data trustworthiness

Assessing the trustworthiness of location data corresponding to individuals is essential in several applications, such as forensic science and epidemic control. To obtain accurate and trustworthy location data, analysts must often gather and correlate information from several independent sources, e.g., physical observation, witness testimony, surveillance footage, etc. However, such information may be fraudulent, its accuracy may be low, and its volume may be insufficient to ensure highly trustworthy data. On the other hand, recent advancements in mobile computing and positioning systems, e.g., GPS-enabled cell phones, highway sensors, etc., bring new and effective technological means to track the location of an individual. Nevertheless, collection and sharing of such data must be done in ways that do not violate an individuals right to personal privacy. Previous research efforts acknowledged the importance of assessing location data trustworthiness, but they assume that data is available to the analyst in direct, unperturbed form. However, such an assumption is not realistic, due to the fact that repositories of personal location data must conform to privacy regulations. In this paper, we study the challenging problem of refining trustworthiness of location data with the help of large repositories of anonymized information. We show how two important trustworthiness evaluation techniques, namely common pattern analysis and conflict/support analysis, can benefit from the use of anonymized location data. We have implemented a prototype of the proposed privacy-preserving trustworthiness evaluation techniques, and the experimental results demonstrate that using anonymized data can significantly help in improving the accuracy of location trustworthiness assessment.