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oai:www.ideals.illinois.edu:2142/99106 2023-07-11 col_2142_5131 col_2142_10761 com_2142_5130 com_2142_10755 com_2142_234

Gunter, Carl A. Lee, Hyun Bin 2018-03-02T19:59:40Z 2018-03-02T19:59:40Z 2020-03-03T10:15:22Z 2017-07-14 2017-08 Privacy-preserving statistical databases are designed to provide information about a population while preventing end-users from learning about an individual. Meanwhile, scholars have shown that a sophisticated adversary can break such assumption against primitive privacy protections. Differential Privacy (DP) measures how likely an adversary learns about an individual from statistical database queries. Recent state-of-the-art Privacy-Enhancing Technologies (PETs) often implement noise injection based mechanisms in order to satisfy a strong DP protection level. While these privacy protection guidelines minimize risks of private information disclosure, many people have raised concerns on impracticality of the implementation. Based on statistical figures and quantitative experiment results, much literature formalized the utility-privacy tradeoff caused by the noise injection. In contrast, this work describes a qualitative analysis of the Laplacian noise mechanism, one of the most prevalently used DP mechanisms, with regards to the utility-privacy tradeoff on various types of visualization products. The dataset used for the analysis is a time series meter readings from smart grid electricity consumption of selected households from the Republic of Ireland. We examined how five types of visualization products, bar graphs, pie charts, heatmaps, linear plots and scatterplots, present information from statistical database queries. Visualization products showed seasonal, daily and weekly periodic consumption patterns such that power utilities can make a qualitative analysis of consumption profiles. We call these patterns as “visual cues.” After applying the Laplacian noise mechanism on these visualization products, we made qualitative observations on the privacy-preserved figures and looked for notable changes. The project provides graphic findings of a relationship among the composability of queries, the number of queries, and the scale of the Laplacian noise. We observed that visualization products which required less than ten queries from the dataset suffered minimal information loss. However, we spotted a high degradation of visual cues when we implemented the noise mechanism to heatmaps with up to 25,200 composable queries. These visualizations no longer conveyed most key information that used to be present on their unprotected counterparts. To best of our knowledge, no state-of-the-art existing pre/post-processing techniques significantly recovered most visual cues. Finally, we found that some visualizations belonged to neither of the first cases. privacy-preserving linear plots (based on 336 composable queries) and scatterplots (based on 3,639 pairs of parallel queries) inherited some visual cues after executing privacy-preserving procedures. We further discovered some pre/post-processing mechanisms that recovered visual cues. Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2019-08-01 The student, Hyun Bin Lee, accepted the attached license on 2017-07-13 at 20:45. The student, Hyun Bin Lee, submitted this Thesis for approval on 2017-07-13 at 20:46. This Thesis was approved for publication on 2017-07-14 at 16:21. DSpace SAF Submission Ingestion Package generated from Vireo submission #11462 on 2018-03-02 at 13:02:12 Made available in DSpace on 2018-03-02T19:59:40Z (GMT). No. of bitstreams: 2 LEE-THESIS-2017.pdf: 2121652 bytes, checksum: 3cb7964de7632573b01a17ec928eb2ca (MD5) LICENSE.txt: 4209 bytes, checksum: a72e507dc984642d2ab6decf912a1343 (MD5) Previous issue date: 2017-07-14 Embargo set by: Seth Robbins for item 105060 Lift date: 2020-03-02T19:59:52Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 105060 Lift date: 2020-03-02T20:02:46Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system U of I Only Restriction Lifted for Item 105060 on 2020-03-03T10:15:22Z. application/pdf http://hdl.handle.net/2142/99106 en Copyright 2017 Hyun Bin Lee Visualization Differential privacy Visualization and differential privacy text text Computer Science Computer Science University of Illinois at Urbana-Champaign Thesis M.S.