Blockchain Consensus: An Introduction to Classical, Blockchain, and Quantum Consensus Protocols

This book is your comprehensive guide to understanding Blockchain and Blockchain consensus algorithms. It covers distributed systems, distributed consensus, and relevant system models. And you'll explore how classical and modern consensus algorithms work. The book also covers quantum consensus and explains the role that quantum computing plays in distributed systems.

Consensus protocols allow participants in distributed systems to agree on a common value, despite faults. It's a fundamentally important construct in distributed systems. As a result of rigorous and ground-breaking research over the last four decades, many consensus mechanisms have been developed and are used in the industry today. However, with the advent of Blockchain technology, a renewed interest has arisen in this area, resulting in more research and innovation.

The first Blockchain, Bitcoin, was invented in 2008 and introduced a novel consensus protocol called Nakamoto consensus, a solution to the Byzantine General's problem formulated almost 30 years ago. Since the introduction of Bitcoin, the interest in Blockchain and consensus protocols has risen exponentially. As a result, researchers from academia and industry have proposed many new consensus mechanisms. While fundamental goals and some techniques remain the same as established classical protocols, these modern protocols introduce innovative methods to achieve consensus in Blockchain. Some classical algorithms have been modified to make them suitable for Blockchain and some new protocols have been developed.

This book is a detailed account of classical distributed consensus and Blockchain consensus algorithms. It explains why and how cryptocurrencies and Blockchain remain secure and decentralized without depending on a trusted third party. In addition, you'll learn how Blockchain can endure, even with hundreds or thousands of participants, out of which some might be malicious. The book introduces quantum consensus, which deals with the problem of reaching agreement in quantum networks and how to enhance classical results.

What You Will Learn

• Understand distributed systems, distributed consensus, and relevant system models and protocols
• Understand Blockchain and Blockchain consensus algorithms
• Know how classical and modern consensus algorithms work
• Know the inner workings of Paxos, RAFT, PBFT, HotStuff, proof of work, proof of stake, GRANDPA, Casper, proof of history, and other consensus protocols
• Understand quantum Byzantine agreement and quantum consensus

Who This Book Is For

Distributed systems and Blockchain students and researchers, Blockchain practitioners, architects, designers, product managers, and developers

This book targets many audiences as well as those with curious minds. It explains the classical consensus mechanisms, Blockchain age consensus protocols, and the latest developments in distributed consensus. The book does not assume any advanced knowledge of Blockchain or distributed systems, but a general understanding of computing and appreciation of Blockchain technology is helpful. Early chapters provide the necessary background to read and understanding consensus-related content quickly.

Readers who already understand classical consensus protocols and distributed systems but want to learn about Blockchain consensus will find the book helpful as it covers Blockchain age protocols in detail. Readers who have come to the Blockchain world without any, or with little, background in distributed systems or classical consensus protocols will find this book equally helpful as it provides a solid understanding of classical consensus protocols.

If you have no experience in Blockchain or don't understand distributed computing in general, this book will give you a solid understanding of both subjects and enable you to conduct further research in this exciting area of distributed computing.

本書是您全面了解區塊鏈和區塊鏈共識算法的指南。它涵蓋了分散式系統、分散式共識和相關系統模型。您將探索傳統和現代共識算法的運作方式。本書還介紹了量子共識，並解釋了量子計算在分散式系統中的作用。

共識協議允許分散式系統中的參與者在存在故障的情況下達成共識。它是分散式系統中的基本重要概念。在過去的四十年中，通過嚴謹而開創性的研究，許多共識機制已被開發並在業界中使用。然而，隨著區塊鏈技術的出現，對這一領域的興趣再次增加，進一步推動了研究和創新。

第一個區塊鏈比特幣於2008年發明，引入了一種新的共識協議，稱為中本聰共識，這是對幾乎30年前提出的拜占庭將軍問題的解決方案。自比特幣的引入以來，對區塊鏈和共識協議的興趣呈指數級增長。因此，來自學術界和工業界的研究人員提出了許多新的共識機制。雖然基本目標和一些技術與傳統的協議相同，但這些現代協議引入了創新的方法來實現區塊鏈共識。一些傳統算法已被修改以適應區塊鏈，並開發了一些新的協議。

本書詳細介紹了傳統分散式共識和區塊鏈共識算法。它解釋了為什麼以及如何在不依賴可信第三方的情況下保持加密貨幣和區塊鏈的安全和去中心化。此外，您還將了解到即使有數百或數千個參與者，其中一些可能是惡意的情況下，區塊鏈如何持久存在。本書還介紹了量子共識，該共識處理了在量子網絡中達成一致的問題以及如何增強傳統結果。

您將學到什麼
- 理解分散式系統、分散式共識和相關系統模型和協議
- 理解區塊鏈和區塊鏈共識算法
- 了解傳統和現代共識算法的運作方式
- 了解Paxos、RAFT、PBFT、HotStuff、工作量證明、權益證明、GRANDPA、Casper、歷史證明和其他共識協議的內部運作方式
- 理解量子拜占庭協議和量子共識

本書適合對象
- 分散式系統和區塊鏈的學生和研究人員，區塊鏈從業人員、架構師、設計師、產品經理和開發人員
- 本書針對多個讀者群體，包括對此感興趣的人。它解釋了傳統共識機制、區塊鏈時代的共識協議以及分散式共識的最新發展。本書不需要對區塊鏈或分散式系統有任何高級知識，但對計算機有一般的理解和對區塊鏈技術的欣賞是有幫助的。早期章節提供了閱讀和理解與共識相關內容所需的必要背景。

對於已經了解傳統共識協議和分散式系統，但想了解區塊鏈共識的讀者，本書將很有幫助，因為它詳細介紹了區塊鏈時代的協議。對於在沒有或只有少量分散式系統或傳統共識協議背景下進入區塊鏈世界的讀者，本書同樣有幫助，因為它提供了對傳統共識協議的扎實理解。

如果您對區塊鏈沒有經驗或對分散式計算一般不了解，本書將使您對這兩個主題有扎實的理解，並使您能夠進行相關研究。

Imran Bashir has an MSc degree in information security from Royal Holloway, University of London, and a background in software development, solution architecture, infrastructure management, information security, and IT service management. His current focus is on the latest technologies such as Blockchain, IoT, and quantum computing. He is a member of the Institute of Electrical and Electronics Engineers (IEEE) and the British Computer Society (BCS). His book on Blockchain technology, Mastering Blockchain, is a widely accepted standard text on the subject. He has worked in various senior technical roles for different organizations around the world. Currently, he is living and working in London, UK.

Imran Bashir擁有倫敦大學皇家霍洛威學院的資訊安全碩士學位，並具有軟體開發、解決方案架構、基礎架構管理、資訊安全和IT服務管理的背景。他目前的專注領域是區塊鏈、物聯網和量子計算等最新技術。他是電機電子工程師學會(IEEE)和英國電腦學會(BCS)的成員。他的區塊鏈技術書籍《精通區塊鏈》是該領域被廣泛接受的標準教材。他曾在世界各地的不同組織擔任過各種高級技術職位。目前，他居住並工作於英國倫敦。