1. Privacy-Preserving Streaming Truth Discovery in Crowdsourcing With Differential Privacy
- Author
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Xiaoyi Pang, Zhibo Wang, Ju Ren, Xuemin Sherman Shen, Yaoxue Zhang, and Dan Wang
- Subjects
Computer Networks and Communications ,business.industry ,Computer science ,Reliability (computer networking) ,Mobile computing ,Crowdsourcing ,computer.software_genre ,Server ,Differential privacy ,Timestamp ,Enhanced Data Rates for GSM Evolution ,Data mining ,Electrical and Electronic Engineering ,business ,computer ,Software ,Edge computing - Abstract
Differential privacy (DP) has gained popularity in truth discovery recently due to its strong privacy guarantee. However, existing DP mechanisms for streaming data publication are not suitable for truth discovery as they fail to consider the different reliabilities of individuals, while the DP-based approaches for truth discovery are not suitable for streaming data because they ignore the correlations between truths over time. To solve this problem, we propose an edge computing based privacy-preserving truth discovery mechanism, PrivSTD, for streaming crowdsourced data to realize high accuracy of discovered truth while protecting the privacy of workers. Specifically, edge servers are introduced between the untrusted cloud server and workers to securely calculate the local truths and workers reliabilities. A truth-dependent budget recycle mechanism is designed for each edge server to adaptively determine the perturbed timestamp and allocate the privacy budget according to the changing pattern of local truths. Besides, a reliability-based perturbation mechanism is proposed to reduce the perturbation magnitude based on worker's reliability. We theoretical analyze the data utility and computation cost of PrivSTD, and prove that PrivSTD can satisfy w-event (,)-differential privacy. Extensive experimental results on synthetic and real-world datasets demonstrate that PrivSTD achieves better utility than the state-of-the-art approaches.
- Published
- 2022