时间：2019.05.24，15:30 — 16:30
题目：Aggregating Crowd Wisdom via Blockchain: Towards Private, Correct, and Robust Realization
Crowdsensing, driven by the proliferation of sensor-rich mobile devices, has emerged as a promising data sensing and aggregation paradigm. Despite useful, traditional crowdsensing systems typically rely on a centralized third-party platform for data collection and processing, which leads to concerns like single point of failure and lack of operation transparency. Such centralization hinders the wide adoption of crowdsensing by wary participants. We therefore explore an alternative design space of building crowdsensing systems atop the emerging decentralized blockchain technology. While enjoying the benefits brought by the public blockchain, we endeavor to achieve a consolidated set of desirable security properties with a proper choreography of latest techniques and our customized designs. We allow data providers to safely contribute data to the transparent blockchain with the confidentiality guarantee on individual data and differential privacy on the aggregation result. Meanwhile, we ensure the service correctness of data aggregation and sanitization by delicately employing hardware-assisted transparent enclave. Furthermore, we maintain the robustness of our system against faulty data providers that submit invalid data, with a customized zero-knowledge range proof scheme. The experiment results demonstrate the high efficiency of our designs on both mobile client and SGX-enabled server, as well as reasonable on-chain monetary cost of running our task contract on Ethereum.
Dr. Cong Wang is currently an Associate Professor (副教授) in the Department of Computer Science, City University of Hong Kong. He received his Ph.D. degree in the Electrical and Computer Engineering from Illinois Institute of Technology, USA, M.E. degree in Communication and Information System, and B.E. in Electronic Information Engineering, both from Wuhan University, China. His current research interests include data and computation outsourcing security in the context of cloud computing, blockchain and decentralized application, network security in emerging Internet architecture, multimedia security, and privacy-enhancing technologies in the context of big data and IoT. He is one of the Founding Members of the Young Academy of Sciences of Hong Kong. He received the Outstanding Supervisor Award in 2017 and the President’s Awards from City University of Hong Kong in 2016. He is a co-recipient of the Best Student Paper Award of IEEE ICDCS 2017, the Best Paper Award of IEEE ICPADS 2018, MSN 2015 and CHINACOM 2009. His research has been supported by multiple government research fund agencies, including National Natural Science Foundation of China, Hong Kong Research Grants Council, and Hong Kong Innovation and Technology Commission. He serves/has served as associate editor for IEEE Transactions on Dependable and Secure Computing, IEEE Internet of Things Journal and IEEE Networking Letters, and TPC co-chairs for a number of IEEE conferences/workshops. He is a senior member of the IEEE, and member of the ACM.