Blockchain-based secure crowdsourcing scheme to support solution reuse

Crowdsourcing is a way to solve complex tasks by publicly collecting solutions on the network. The crowdsourcing system that provides task completion and solution reuse facilitates human life and promotes economic development. With the rise of blockchain technology, it is possible to design and implement a decentralized crowdsourcing scheme. However, due to the nature of data sharing on the blockchain, there are many challenges in the blockchain-based crowdsourcing scheme. In this paper, we first classify the required properties of blockchain-based decentralized crowdsourcing scheme including fairness, reusability and integrity. And then we propose a novel blockchain-based secure crowdsourcing scheme to support solution reuse using the Pedersen commitment, Paillier cryptosystem, secure hash function and Diffie-Hellman key exchange. The security analysis shows that our scheme satisfies the above requirements. Finally, we simulated the crowdsourcing task that may exist in the real world and evaluated the experimental results.