Privacy-preserving Task Assignment in Spatial Crowdsourcing
An Liu1,2, Member, CCF, Zhi-Xu Li1,*, Member, CCF, Guan-Feng Liu1, Member, CCF, Kai Zheng1,3, Member, CCF, Min Zhang1, Member, CCF, Qing Li4, Senior Member, IEEE Xiangliang Zhang2, Member, IEEE
1 School of Computer Science and Technology, Soochow University, Suzhou 215006, China;
2 King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia;
3 Beijing Key Laboratory of Big Data Management and Analysis Methods, Beijing 100872, China;
4 Department of Computer Science, City University of Hong Kong, Hong Kong, China
Abstract With the progress of mobile devices and wireless networks, spatial crowdsourcing (SC) is emerging as a promising approach for problem solving. In SC, spatial tasks are assigned to and performed by a set of human workers. To enable effective task assignment, however, both workers and task requesters are required to disclose their locations to untrusted SC systems. In this paper, we study the problem of assigning workers to tasks in a way that location privacy for both workers and task requesters are preserved. We first combine Paillier cryptosystem with Yao's garbled circuits to construct a secure protocol that assigns the nearest worker to a task. Considering that this protocol cannot scale to a large number of workers, we then make use of Geohash, a hierarchical spatial index to design a more efficient protocol that can securely find approximate nearest workers. We theoretically show that these two protocols are secure against semi-honest adversaries. Through extensive experiments on two real-world datasets, we demonstrate the efficiency and effectiveness of our protocols.
This work was partially supported by King Abdullah University of Science and Technology (KAUST) and the National Natural Science Foundation of China under Grant Nos. 61572336, 61632016, 61402313, 61572335, and 61472337.
About author: An Liu is an associate professor in the School of Computer Science and Technology at Soochow University, Suzhou. He received his Ph.D. degree in computer science from both City University of Hong Kong (CityU), Hong Kong, and University of Science and Technology of China (USTC), Hefei, in 2009. His research interests include spatial databases, crowdsourcing, data security and privacy, and cloud/service computing.
Cite this article:
An Liu, Zhi-Xu Li, Guan-Feng Liu, Kai Zheng, Min Zhang, Qing Li, Xiangliang Zhang.Privacy-preserving Task Assignment in Spatial Crowdsourcing[J] Journal of Computer Science and Technology, 2017,V32(5): 905-918
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