Decentralized Anonymous Crowdsourcing with Blockchain and Anonymous Payments

Decentralizing crowdsourcing through blockchain technology eliminates the need for trusted third-party intermediaries that may introduce social biases in data aggregation, thereby enhancing transparency and ensuring appropriate rewards for workers. However, open permissionless blockchain platforms typically disclose all transaction data on public ledgers, which compromises the privacy and anonymity of workers and encourages free-riding. Blockchain-based anonymous crowdsourcing systems have recently emerged, offering anonymity but requiring identity registration for workers and a trusted setup for key generation. These systems in general, fail to support anonymous payments, potentially compromising worker identities. In this paper, we integrate anonymous payments into crowdsourcing, eliminating the need for identity registration and trusted setup, thus fostering open and anonymous participation from any worker. Our solution utilizes the decentralized anonymous payment system framework, such as Zerocoin, and includes staking mechanisms for participation in crowdsourcing as well as efficient one-out-of-many zero-knowledge proofs. Additionally, our empirical evaluations reveal that the system incurs moderate and practical gas costs.