Improved Schemes for Managing Reputation in a Blockchain-based Decentralized Marketplace

Very recently, in an attempt to reduce the uncertainty associated with notoriously unreliable buyer feedback, researchers proposed a blockchain-based trust and reputation management system, where a Smart Contract manages all aspects of a transaction: setting up a contract, interacting with the two parties, and finally evaluating and providing feedback on the buyer/seller performance at the end of each transaction. They have also proposed a data structure that manages seller reputation scores inside the blockchain. In this paper, we provide two novel reputation management schemes that significantly improve on these methods. Our first such scheme is adaptive; the second one is randomized, wherein decisions about managing the underlying data structure are made based on coin flips. We provide analytical performance predictions and verify, empirically, by extensive simulation, the accuracy of our predictions. Our schemes are shown to result in more efficient query execution with enhanced block structure schemes.