CrowdBC: A Blockchain-Based Decentralized Framework for Crowdsourcing

Crowdsourcing systems which utilize the human intelligence to solve complex tasks have gained considerable interest and adoption in recent years. However, the majority of existing crowdsourcing systems rely on central servers, which are subject to the weaknesses of traditional trust-based model, such as single point of failure. They are also vulnerable to distributed denial of service (DDoS) and Sybil attacks due to malicious users involvement. In addition, high service fees from the crowdsourcing platform may hinder the development of crowdsourcing. How to address these potential issues has both research and substantial value. In this paper, we conceptualize a blockchain-based decentralized framework for crowdsourcing named CrowdBC, in which a requester's task can be solved by a crowd of workers without relying on any third trusted institution, users' privacy can be guaranteed and only low transaction fees are required. In particular, we introduce the architecture of our proposed framework, based on which we give a concrete scheme. We further implement a software prototype on Ethereum public test network with real-world dataset. Experiment results show the feasibility, usability, and scalability of our proposed crowdsourcing system.

1 Introduction

Over the past few years, crowdsourcing has gained considerable interest and adoption since it is coined in 2006 by Jeff Howe [1]. It is a distributed problem-solving model through an open call for solutions. Nowadays, many large companies choose crowdsourcing as a problem-solving method, ranging from web and mobile development to t-shirt designs. There are numerous famous crowdsourcing applications such as Upwork, Amazon Mechanical Turk and UBER. We can expect that this field will change the working style of people significantly.