Towards Efficient, Robust, and Privacy-Preserving Incentives for Crowdsensing via Blockchain

With the explosive development of mobile devices, mobile crowdsensing (MCS) has emerged as a promising approach for large-scale sensing data collection. In the research of MCS, blockchain technology has been widely adopted to decentralize the traditional mobile crowdsensing and tackle the problem of single point of failure. Incentive mechanisms are devised to boost participation with fairness and truthfulness. However, to better determine the incentive strategy, participants’ privacy can be disclosed on top of the blockchain and obtained by adversaries during the transmission and execution of user data, leading to serious security issues. In this paper, we propose a two-stage incentive scheme with efficiency, robustness and privacy preservation considered based on the combination of blockchain technology and Trusted Execution Environment (TEE). Detailedly, we design two kinds of smart contracts, where on-chain public contracts support the procedure of general crowdsensing interactions, and off-chain private ones enabled by TEE complete the privacy-preserving computations, including an online incentive mechanism for worker recruitment decisions and a truth discovery algorithm for data aggregation. Recovery mechanism and hash check mechanism are introduced to avoid TEE provider failures and TEE providers’ attacks, respectively. Our scheme is proved to be theoretically secure in terms of private information protection, worker participation anonymity, and data aggregation privacy. Experimental results also verify the feasibility and superiority of our incentive scheme.