Abstract: Blockchain is a kind of distributed ledger that combines time series data into a chain structure, and the crypto-
graphy guarantees transaction data to be tamper-resistant. It is a new distributed computing model and decentralized infrastructure. Blockchain technology has the characteristics of decentralization, trust building, collective maintenance, transaction fairness and transparency, tamper-resistant, and traceability. The research of blockchain has become a hot point in industry and academia. This paper introduces the main components of the blockchain, elaborates the basic principles of blockchain technology, smart contracts, consensus mechanisms and other key technologies. It provides a new and optimized direction for financial, Internet of Things, supply chain, and medical system applications. This paper summarizes the shortcomings of blockchain technology in terms of security, efficiency and privacy protection, and proposes effective methods for consensus mechanisms, anonymity issues and efficiency issues. That provides useful reference and guidance for the further development and improvement of blockchain technology.

Key words: blockchain, distributed ledger, consensus mechanism, smart contract, blockchain application

摘要： 区块链是一种将时序数据以链式结构组合而成、以密码学机制保证交易数据不可篡改的分布式账本，是一种新型分布式计算模式与去中心化基础构架。区块链技术具有去中心化、建立信任关系、集体维护、交易公平和透明、不可篡改、可溯源等特征，已成为工业界和学术界的研究热点。介绍了区块链的组成元素，详细阐述了区块链的基本原理、智能合约、共识机制等关键技术，结合金融、物联网、供应链、医疗系统应用场景，讨论了其利用区块链技术的优化方向。总结了区块链技术在安全、效率、隐私保护等方面存在的不足，给出了相应的应对措施。提出了改进共识机制、匿名性和系统吞吐量的有效方法，为区块链技术的进一步发展和完善提供有益的借鉴和指导。

关键词: 区块链, 分布式账本, 共识机制, 智能合约, 区块链应用