Abstract

Blockchain sharding is a significant technical branch of improving the scalability of blockchain systems. It is regarded as one of the potential solutions that can achieve on-chain scaling and significantly improve the scalability of blockchains without alleviating the decentralization feature of blockchain. To provide a reference and inspire participation from both the academic and industrial sectors in the research on blockchain sharding, we have walked through the state-of-the-art studies published in the past three years on blockchain sharding. We also conducted experiments to show the performance of representative sharding protocols such as Monoxide, LBF, Metis, and BrokerChain. We finally envision the potential challenges and promising future of sharding techniques in terms of the urgent demands of high throughput required by emerging applications such as Web3, Metaverse, and Decentralized Finance (DeFi). We hope that this article is helpful to researchers, engineers, and educators, and will inspire subsequent studies in the field of blockchain sharding.