A System to Privacy Preserving and Guarantee Worker Rewards in Blockchain-Based Crowdsourcing

The crowdsourcing platform is a very popular platform where individuals collaborate to solve complex problems. Requesters share tasks that they are unable to solve, and workers perform these tasks based on their expertise. In today's digital world, privacy is a major concern for users of this platform. Most workers prefer to keep their personal information, such as age, location, and interests, private. Additionally, ensuring that workers receive rewards after completing their tasks is another reason for participating in crowdsourcing. However, traditional crowdsourcing requires a third party to send the rewards to workers, which can be unreliable and destructive. Therefore, most workers prefer platforms that guarantee protection of their privacy and full payment of their rewards. In this article, we use blockchain technology and smart contracts based on Ethereum to eliminate the need for an unreliable third party and make workers fully assured that they will receive their full rewards. In addition, we improve worker privacy protection using encryption algorithms and show that worker privacy can be largely protected by a feature-based encryption algorithm with a ciphertext policy.