A Smart Contract-based Decentralized Marketplace System to Promote Reviewer Anonymity.

In recent years, online marketplaces have seen a large increase in business. Managing and making sellers' reputations available to buyers is vital for the success of these markets since buyers may be dealing with unknown online sellers. Typically, prospective buyers assess sellers' performance by looking at past buyers' reviews, prior to making a purchase. In current online marketplaces, buyers' reviews are associated with their identities, raising privacy issues. Several decentralized solutions have been proposed using blockchain technologies to solve this problem. However, some of these systems are not entirely decentralized or have some weaknesses such as requiring a trusted third party. In this paper, we propose a system for decentralized reviewing that trades off cost for unlinkability. Using blockchain-based smart contracts, we propose a fully decentralized marketplace to provide reviewers with a secure and trusted platform. Here, buyers can use one-time identities to provide feedback on their transactions. The system also ensures that a review can only be submitted after a transaction is completed, and that at most one review may be submitted per transaction. The system enforces these properties through blockchain technologies and smart contracts. In addition, we propose an innovative approach to encourage buyers to submit reviews. The system has been prototyped using Remix IDE.