This document proposes a decentralized data marketplace platform based on Ethereum blockchain. It discusses some limitations of existing centralized data marketplaces, where users must trust the centralized authority. The proposed system aims to make data buying and selling cheaper, faster, easier and more trustworthy. It describes key components like a smart contract for handling transactions, and a web application for users to authenticate, buy and sell data. Implementation details are provided for a prototype built using Django, Python, Solidity and a private Ethereum blockchain network. Future work ideas include adding encryption of stored data locations and migrating file storage to the cloud.