区块链分片技术综述

区块链作为分布式账本的关键技术之一，其去中心化、可匿名、不可篡改的特性受到学术界和工业界的青睐，被广泛应用于金融、数字货币、公共服务等领域。分片技术作为区块链扩容的主流方式之一，能够在不降低区块链去中心化程度的同时实现高性能的链上扩容，从而解决区块链可拓展性不足以及吞吐量较低的问题。介绍近年来出现的分片技术以及相关协议，总结分片技术的关键理论与方法，从分片配置、重配置、片内共识协议、跨片共识协议、状态存储等方面对分片技术方案进行对比，归纳不同分片方案在网络分片、交易分片、状态分片等设计中存在的优势和不足。同时，阐述一些经典分片技术在性能和实现方式上的特点，对许可区块链和无许可区块链、片内共识协议、跨片共识协议、准入性方案、状态分片方式等进行分析和概述。在此基础上，从分片内、分片间以及系统层级的角度总结分片技术当前所面临的困境和挑战，并对该领域的发展前景及未来研究方向加以展望。

Survey on Blockchain Sharding Technology

As one of the key technologies of distributed ledger, blockchain is favored by academia and industry for its decentralized, anonymous, and tamper-proof characteristics.It is widely used in finance, digital currency, public services, and other fields.As one of the mainstream methods of blockchain, sharding technology can realize high-performance capacity expansion on the chain without reducing the degree of decentralization of the blockchain, to address problems of insufficient scalability and low throughput.This study introduces the sharding technology and related protocols of recent years, summarizing the key theories and methods of sharding, comparing the sharding technology schemes in terms of of sharding configuration, reconfiguration, intrachip consensus protocol, cross-chip consensus protocol, and state storage.The advantages and disadvantages of different sharding schemes are further summarized with respect to the design of the network, transaction, and sharding state.The characteristics of some classical fragmentation technologies are expounded upon in terms of performance and implementation mode, analyzing and summarizing licensed blockchain and unlicensed blockchain on-chip consensus protocol, cross-chip consensus protocol, access scheme, state fragmentation mode, and the like.On this basis, the current difficulties and challenges of sharding technology are presented from the perspective of system level intra-sharding and inter-sharding, suggesting future development prospects and research directions in this field.