SmartReview: A Blockchain-based Transaction Review System for Decentralized Marketplaces

Over the last few years, e-commerce has seen tremendous growth, with much of the businesses centered around centralized marketplaces such as Amazon and eBay. However, these markets suffer from single-point failures and market monopolies. Decentralized marketplaces overcome these deficiencies by governing through consensus. For these markets to become popular, it is necessary to provide customers with a trustworthy reputation system based on honest reviews. Today’s review systems suffer from several weaknesses including scant buyer feedback, often based on emotion rather than facts. To overcome these weaknesses, in this paper, we propose SmartReview, an automated review system that is based on blockchain and smart contracts. SmartReview system is built as a multilayered architecture, with each layer handling different aspects of transaction execution in decentralized markets. The review module is conceived to be a smart contract that takes the contract terms and conditions and the evidence provided by the buyer and seller as inputs, and employs advanced computer vision and machine learning techniques to arrive at a quantitative and qualitative review for each transaction. These reviews are objective and do not suffer from reviewer bias. Further, the reputation layer takes these as inputs and arrives at a dynamic predictive reputation for the sellers, by employing time-series-based prediction algorithms. The effectiveness of these layers is illustrated through examples. While what is described is a proof-of-concept, future plans are to build a full-fledged system.