区块链理论研究进展

Research Progress on Theory of Blockchains

区块链技术是一门新兴的技术,受到各行各业的广泛关注.各个国家正在积极研究区块链技术可能给金融乃至生活的方方面面带来的变革.本文先从比特币区块链的视角出发,通过了解它的运行机制、基本特征、关键技术、技术挑战等,给读者建立一个对区块链的直观感受.然后给出区块链的形式化定义,并总结目前区块链在相关密码技术、安全性分析、共识机制、隐私保护、可扩展性等方面的最新研究进展.密码技术是保障区块链安全的关键技术之一,也是实现区块链具体应用的基本手段.本文同时指出了多种密码技术如特殊数字签名、零知识证明、同态密码、安全多方计算等在区块链系统中的(潜在)应用价值.尽管区块链技术的研究和应用发展迅速并取得很大进展,但区块链所面临的诸如吞吐量低、延迟高、耗能高等一系列技术瓶领,严重影响大规模应用的真正落地,区块链技术的研究和应用还有很长的路要走,需要各方共同努力.

Blockchain is an emerging technology that has received an exceptional amount of attention from all walks of life. Many countries are actively studying how blockchain technology could change finance and even aspects of our lives. In this paper, by introducing the operating mechanism,basic features, key technologies, and technical challenges of the Bitcoin blockchain, we firstly build an intuitive feeling of blockchains for readers. Then we propose a formal definition of blockchains, and summarize the current research progress of blockchains in cryptography, security analysis, consensus,privacy, and scalability. Cryptography is one of the key technologies ensuring security in blockchains,and is also the basic means to realize the specific applications of blockchains. In this paper, we also point out the potential application value of the various cryptographic techniques in blockchains, such as special digital signatures, zero-knowledge proofs, homomorphic ciphers, and secure multi-party computations. Although the research and application of blockchain technology has developed rapidly and made great progress, blockchain technology faces a series of technical challenges such as low throughput, high latency, and high energy consumption, which seriously affects its large-scale applications.Therefore, the research and application of blockchains still has a long way to go, and people need to work together.