Distributed Trusted Computing for Blockchain-Based Crowdsourcing

Abstract

A centralized trusted execution environment (TEE) has been extensively studied to provide secure and trusted computing. However, a TEE might become a throughput bottleneck if it is used to evaluate data quality when collecting large-scale data in a crowdsourcing system. It may also have security problems compromised by attackers. Here, we propose a scheme, named dTEE, for building a platform for providing distributed trusted computing by leveraging TEEs. The platform is used as an infrastructure of trusted computations for blockchain-based crowdsourcing systems, especially to securely evaluate data quality and manage remuneration: these operations are handled by a TEE group. First, dTEE uses a public blockchain with smart contracts to manage TEEs without reliance on any trusted third parties. Second, to update TEE registration information and rule out zombie TEEs, dTEE uses a reporting mechanism. To attract TEE owners to join in and provide service of trusted computations, it uses a fair monetary incentive mechanism. Third, to account for malicious attackers, we design a model with Byzantine fault tolerance, not limited to a crash-failure model. Finally, we conduct an extensive evaluation of our design on a local cluster. The results show that dTEE finishes evaluating 10,000 images within one minute and achieves about 65 tps throughput when evaluating Sudoku solution data with collective signatures both in a group of 120 TEEs.

Trusted Computing System Based on Blockchain

“…The calculator not only needs to calculate the correct use case but also Test cases need to be calculated, which will lead to repeated and inefficient calculations, and the task issuer also needs to calculate the correct test cases for verification, which contradicts the condition that the issuer does not have computing power. Xu Liang [7] proposed a trusted distributed computing system based on blockchain technology, which divides the blockchain nodes into storage nodes and computing nodes, and then elects the master node and distribution node from the computing nodes to verify the computing tasks respectively. The distribution of the distribution, although the calculation task only requires the calculation node to perform one calculation, but the verification requires the repeated verification of the master node and each storage node.…”