Blockchain-based decentralized reputation system in E-commerce environment

Abstract With the rapid development of E-commerce, more and more people are used to shopping online, in which the reputation scores of sellers play an important role in helping consumers purchase satisfactory products. However, in the existing E-commerce environments, the reputation scores of users (including sellers and buyers) are centrally computed and stored on a centralized cloud server, which might make errors or even engage in fraud and forgery. To address this issue, we propose a blockchain-based decentralized reputation system (BC-DRS) in the E-commerce environment, i.e., online shopping. In this system, the product information including product descriptions and comments is stored in the interplanetary file system (IPFS) and the corresponding address is returned, and the returned address and the reputation scores of users are stored on the blockchain. The reputation evaluation is implemented by designing and deploying a smart contract on the blockchain. Different from the traditional centralized reputation systems (CRSs), the proposed BC-DRS can protect the product information and users reputation scores from intentional and unintentional modifications, since it is very hard to change any data stored in the blockchain and IPFS. Also, as the reputation scores of users are computed and updated by all the ratings of their transactions weighted by the practical transaction factors, it is effective to resist the common attacks, i.e., unfair rating and collusion. In addition, this system also contains a monetary incentive mechanism for the evaluation, which is helpful to form a virtuous circle in online shopping. The proposed BC-DRS is simulated on the popular blockchain platform, i.e., Ethereum with Solidity language. The experimental results and analysis demonstrate that the proposed BC-DRS has desirable usability and reliability.