今天起，我们一起学习比特币领域经典的作品Mastering Bitcoin ，国内译作《精通比特币》。这本书的作者是Andreas M. Antonopoulos是国外比特币圈一位前辈，这本书被誉为比特币最好的技术参考。
《精通比特币》的第一版中文版已经在国内出版，第二版英文版于2017年7月完成，目前没有中文纸质版本。但是在网络上有网友贡献出了英文版。以下是相关链接：
书籍主页：
https://github.com/bitcoinbook/bitcoinbook
英文版链接：
https://github.com/bitcoinbook/bitcoinbook/blob/develop/book.asciidoc
中文版链接:
https://bitcoinbook.info/wp-content/translations/cmn/book.pdf
我会选择英文版作为我们的学习主材料，针对这些英文材料，梳理出逻辑，并写出我的理解。由于已经有现成的中文版译本，因此我不会对英文逐句翻译；对于一些比较简单的部分，我会择机省略。但是对其中的部分英文用法，我会给出解释。我期待能达到的效果是，既能把比特币给学了，顺便把英语的表达积累。作为读者，建议你先阅读英文，尝试自己搞明白，再看我的文字；如果英文理解有困难，那就自行参考一下译本。不要只看中文，不看英文，这样你会看不懂的。
好，下面我从前言开始梳理：
0.前言
前言地址参见https://github.com/bitcoinbook/bitcoinbook/blob/develop/preface.asciidoc
由于前言有许多说明性的文字，我仅从中摘录部分论述。
Writing the Bitcoin Book
I first stumbled upon bitcoin in mid-2011. My immediate reaction was more or less "Pfft! Nerd money!" and I ignored it for another six months, failing to grasp its importance. This is a reaction that I have seen repeated among many of the smartest people I know, which gives me some consolation. The second time I came across bitcoin, in a mailing list discussion, I decided to read the whitepaper written by Satoshi Nakamoto to study the authoritative source and see what it was all about. I still remember the moment I finished reading those nine pages, when I realized that bitcoin was not simply a digital currency,but a network of trust that could also provide the basis for so much more than just currencies. The realization that "this isn’t money, it’s a decentralized trust network," started me on a four-month journey to devour every scrap of information about bitcoin I could find. I became obsessed and enthralled, spending 12 or more hours each day glued to a screen, reading, writing, coding, and learning as much as I could. I emerged from this state of fugue, more than 20 pounds lighter from lack of consistent meals, determined to dedicate myself to working on bitcoin.
这段有几个信息点值得注意：
(1) 作者在第一次接触比特币的时候，并没有太在意，忽略了六个月的时间；第二次是在邮件讨论中遇到比特币，这时才开始读中本聪的白皮书（这份白皮书的解析我们已经写完了，参见《比特币白皮书解析 | 从零开始区块链》）。作者想必是懊悔的，但是后面他发现其他很多聪明人，在第一次遇到比特币，也是这样的反应，却给了他一些安慰。不过作者还是幸运的，有的人每一次都说要读，但是最后仍然是不了了之，一拖十几年，甚至一辈子就过去了。看一下你的待办清单，有多少事情是你一直想做但是却没有做的呢？
(2) 作者在研究完白皮书以后，意识到这不仅仅是电子货币，而是一种信任的网络，这不只是可以为货币打下基础，还可以是很多事情的基础。在意识到这个问题以后，作者沉迷学习四个月，每天研究12个小时，盯着电脑，阅读、编码、写作，之后瘦了20磅（18斤）。注意这里的became obsessed and enthralled，glued to a screen，emerged from this state of fugue都是很好的表达，英语写作可以借鉴。
(3) 这里要学习的是作者的精神。从描述上看，作者是内驱力很强的一个人。做一件事情，不是因为别人给你打了鸡血，而是你自己通过学习，发现一件事情的极端重要意义，从而自主产生动力，不惜一切代价精进。这是区分人与人成就的重要原因。我记得，李笑来老师在讲他最初接触到比特币的时候，也有类似的场景片断。其实在任何领域，要有一定的成绩，都要有这样一种“钉钉子”精神，完成自己的原始知识资本积累。
(4) 在十九大报告中有这样一句话，“增强狠抓落实本领，坚持说实话、谋实事、出实招、求实效，把雷厉风行和久久为功有机结合起来，勇于攻坚克难，以钉钉子精神做实做细做好各项工作。”
Two years later, after creating a number of small startups to explore various bitcoin-related services and products, I decided that it was time to write my first book.Bitcoin was the topic that had driven me into a frenzy of creativity and consumed my thoughts; it was the most exciting technology I had encountered since the internet.It was now time to share my passion about this amazing technology with a broader audience.
这里作者深情并茂地说：“比特币让我创意勃发，让我殚精竭虑；就互联网出来以来，我遇到的最激动人心的技术”。那就让我们跟着这位瘦下来20磅的作者，开始精通比特币的旅程吧。
剩下的部分作者讲了一些书面向的读者，封面的隐喻以及阅读指南，请大家自行阅读。
https://github.com/bitcoinbook/bitcoinbook/blob/develop/preface.asciidoc
1.简介
这一部分基础内容由于在比特币白皮书的解析部分已经有所讨论，所以行文会比较简略。原文地址在
https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch01.asciidoc。
What Is Bitcoin?
Bitcoin is a collection of concepts and technologies that form the basis of a digital money ecosystem. Units of currency called bitcoin are used to store and transmit value among participants in the bitcoin network. Bitcoin users communicate with each other using the bitcoin protocol primarily via the internet, although other transport networks can also be used. The bitcoin protocol stack, available as open source software, can be run on a wide range of computing devices, including laptops and smartphones, making the technology easily accessible.
比特币是一套概念与技术，形成的电子现金生态系统。在解析比特币白皮书的文章中，我们已经对电子现金需要有的基本特点进行过分析。
Users can transfer bitcoin over the network to do just about anything that can be done with conventional currencies, including buy and sell goods, send money to people or organizations, or extend credit. Bitcoin can be purchased, sold, and exchanged for other currencies at specialized currency exchanges.Bitcoin in a sense is the perfect form of money for the internet because it is fast, secure, and borderless.
比特币在某种程度上，是现金互联网的最佳形式，因为快、安全、无界。
Unlike traditional currencies, bitcoin are entirely virtual. There are no physical coins or even digital coins per se. The coins are implied in transactions that transfer value from sender to recipient.Users of bitcoin own keys that allow them to prove ownership of bitcoin in the bitcoin network.With these keys they can sign transactions to unlock the value and spend it by transferring it to a new owner. Keys are often stored in a digital wallet on each user’s computer or smartphone. Possession of the key that can sign a transaction is the only prerequisite to spending bitcoin, putting the control entirely in the hands of each user.
比特币通过密钥的方式来证明所有权。如果你掌握了密钥，你就掌握了对应的货币。
Bitcoin is a distributed, peer-to-peer system. As such there is no "central" server or point of control. Bitcoin are created through a process called "mining," which involves competing to find solutions to a mathematical problem while processing bitcoin transactions. Any participant in the bitcoin network (i.e., anyone using a device running the full bitcoin protocol stack) may operate as a miner, using their computer’s processing power to verify and record transactions. Every 10 minutes, on average, a bitcoin miner is able to validate the transactions of the past 10 minutes and is rewarded with brand new bitcoin.Essentially, bitcoin mining decentralizes the currency-issuance and clearing functions of a central bank and replaces the need for any central bank.
比特币的挖矿机制，将中央银行的货币发行与清算工作去中心化，从而不需要任何中央银行。
The bitcoin protocol includes built-in algorithms that regulate the mining function across the network.The difficulty of the processing task that miners must perform is adjusted dynamically so that, on average, someone succeeds every 10 minutes regardless of how many miners (and how much processing) are competing at any moment. The protocol also halves the rate at which new bitcoin are created every 4 years, and limits the total number of bitcoin that will be created to a fixed total just below 21 million coins. The result is that the number of bitcoin in circulation closely follows an easily predictable curve that approaches 21 million by the year 2140. Due to bitcoin’s diminishing rate of issuance, over the long term, the bitcoin currency is deflationary. Furthermore,bitcoin cannot be inflated by "printing" new money above and beyond the expected issuance rate.
比特币有内置的算法用于调控挖矿速度，以保证每10分钟挖到一次。比特币总数是2100万枚，预计到2140年全部挖出。比特币是通缩型货币，无法通过“印钞”的方式，增发货币。
Behind the scenes, bitcoin is also the name of the protocol, a peer-to-peer network, and a distributed computing innovation. The bitcoin currency is really only the first application of this invention.Bitcoin represents the culmination of decades of research in cryptography and distributed systems and includes four key innovations brought together in a unique and powerful combination. Bitcoin consists of:
A decentralized peer-to-peer network (the bitcoin protocol)
A public transaction ledger (the blockchain)
A set of rules for independent transaction validation and currency issuance (consensus rules)
A mechanism for reaching global decentralized consensus on the valid blockchain (Proof-of-Work algorithm)
比特币代表了过去几十年密码学研究和分布式系统的研究顶点，包括以下四个方面的创新：
(1) 分布式的点对点网络
(2) 一套公众账簿系统
(3) 一套交易验证和发币的规则
(4) 一套在区块链上达到共识的机制
As a developer, I see bitcoin as akin to the internet of money, a network for propagating value and securing the ownership of digital assets via distributed computation. There’s a lot more to bitcoin than first meets the eye.
比特币就像金钱的互联网，可以通过分布式的计算方式，传播价值，保障电子资产所有权。
In this chapter we’ll get started by explaining some of the main concepts and terms, getting the necessary software, and using bitcoin for simple transactions. In following chapters we’ll start unwrapping the layers of technology that make bitcoin possible and examine the inner workings of the bitcoin network and protocol.
Digital Currencies Before Bitcoin
The emergence of viable digital money is closely linked to developments in cryptography. This is not surprising when one considers the fundamental challenges involved withusing bits to represent value that can be exchanged for goods and services. Three basic questions for anyone accepting digital money are:
Can I trust that the money is authentic and not counterfeit?
Can I trust that the digital money can only be spent once (known as the “double-spend” problem)?
Can I be sure that no one else can claim this money belongs to them and not me?
Issuers of paper money are constantly battling the counterfeiting problem by using increasingly sophisticated papers and printing technology. Physical money addresses the double-spend issue easily because the same paper note cannot be in two places at once. Of course, conventional money is also often stored and transmitted digitally. In these cases, the counterfeiting and double-spend issues are handled by clearing all electronic transactions through central authorities that have a global view of the currency in circulation. For digital money, which cannot take advantage of esoteric inks or holographic strips, cryptography provides the basis for trusting the legitimacy of a user’s claim to value. Specifically, cryptographic digital signatures enable a user to sign a digital asset or transaction proving the ownership of that asset. With the appropriate architecture, digital signatures also can be used to address the double-spend issue.
这里讲的是传统的现金安全与电子现金安全的异同，与我们前一篇文章中谈到的信息要点类似，参见《比特币白皮书解析 | 从零开始区块链》。这一部分英语我就不展开介绍，但是可以分享一个学习思路：如果你对一件事情本身就很了解，或者你对这件事情的了解，是通过母语或者其他语言习得，那你用英语或者你需要学习的语言，再去读关于这个主题的讨论，你的语言学习吸收效率会很高。
When cryptography started becoming more broadly available and understood in the late 1980s, many researchers began tryingto use cryptography to build digital currencies. These early digital currency projects issued digital money, usually backed by a national currency or precious metal such as gold.
Although these earlier digital currencies worked, they were centralized and, as a result,were easy to attack by governments and hackers. Early digital currencies used a central clearinghouse to settle all transactions at regular intervals, just like a traditional banking system. Unfortunately, in most cases these nascent digital currencies were targeted by worried governments and eventually litigated out of existence. Some failed in spectacular crashes when the parent company liquidated abruptly. To be robust against intervention by antagonists, whether legitimate governments or criminal elements, a decentralized digital currency was needed to avoid a single point of attack. Bitcoin is such a system, decentralized by design, and free of any central authority or point of control that can be attacked or corrupted.
这一部分在我以前的文章里面也提到过，中心化的问题就是单点容易受到攻击，但是比特币采用了去中心化的方式，通过数字签名来实现验证和所有权。
History of Bitcoin
Bitcoin was invented in 2008 with the publication of a paper titled "Bitcoin: A Peer-to-Peer Electronic Cash System,"[1] written under the alias of Satoshi Nakamoto (see [satoshi_whitepaper]). Nakamoto combined several prior inventions such as b-money and HashCash to create a completely decentralized electronic cash system that does not rely on a central authority for currency issuance or settlement and validation of transactions. The key innovation was to use a distributed computation system (called a "Proof-of-Work" algorithm) to conduct a global "election" every 10 minutes, allowing the decentralized network to arrive at consensus about the state of transactions. This elegantly solves the issue of double-spend where a single currency unit can be spent twice. Previously, the double-spend problem was a weakness of digital currency and was addressed by clearing all transactions through a central clearinghouse.
比特币白皮书我们之前已经梳理完了，我读到这里的时候，内心啊哈一笑。
The bitcoin network started in 2009, based on a reference implementation published by Nakamoto and since revised by many other programmers. The implementation of the Proof-of-Work algorithm (mining) that provides security and resilience for bitcoin has increased in power exponentially, and now exceeds the combined processing power of the world’s top supercomputers. Bitcoin’s total market value has at times exceeded $135 billion US dollars, depending on the bitcoin-to-dollar exchange rate.The largest transaction processed so far by the network was $400 million US dollars, transmitted instantly and processed for a fee of $1.
这里的数据是，比特币目前最大的一笔交易是4亿美金的转账，手续费1美金。不过现在有比这个更高的交易了。
Satoshi Nakamoto withdrew from the public in April 2011, leaving the responsibility of developing the code and network to a thriving group of volunteers. The identity of the person or people behind bitcoin is still unknown. However, neither Satoshi Nakamoto nor anyone elseexerts individual control over the bitcoin system, which operates based on fully transparent mathematical principles, open source code, and consensus among participants.The invention itself is groundbreaking and has already spawned new science in the fields of distributed computing, economics, and econometrics.
这里说了两个重要的信息点：
(1) 比特币开发出了以后，即使中本聪也无法控制
(2) 比特币这项发明是突破性的，并且带来了分布式计算、经济学以及计量经济学的新领域。
A Solution to a Distributed Computing Problem
Satoshi Nakamoto’s invention is also a practical and novel solution to a problem in distributed computing, known as the "Byzantine Generals' Problem." Briefly, the problem consists of trying toagree on a course of action or the state of a system by exchanging information over an unreliable and potentially compromised network. Satoshi Nakamoto’s solution, which uses the concept of Proof-of-Work to achieve consensus without a central trusted authority, represents a breakthrough in distributed computing and has wide applicability beyond currency. It can be used to achieve consensus on decentralized networks to prove the fairness of elections, lotteries, asset registries, digital notarization, and more.
比特币用了一种新的方式解决拜占庭问题，即在一个不受信任的网络环境下，不同角色如何通过交换信息，来对行动或者状态达成一致。
网络是一个充满了不信任的危险环境，虽然对小白来说不是这样的。我以安全行业的从业者为例，这个行业里很多安全工程师是在虚拟机里看邮件的，因为邮件往往是重要的攻击风险来源，而且对于安全工程师，有一种有趣的说法，两个人的最高信任就是，你发了一个邮件，有一个附件，我毫不犹豫地点开。
要在这样的不信任的环境中，构建信任，是密码学一直以来研究的课题。比特币就是在这个方向上的一次积极的尝试。
Bitcoin Uses, Users, and Their Stories
Choosing a Bitcoin Wallet
Getting Your First Bitcoin
接下来的小节，原书举了几个比特币的应用场景，以及如何购买第一枚比特币。该部分内容相对简单，在此就不予以详述。可以阅读英文链接
https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch01.asciidoc#bitcoin-uses-users-and-their-stories
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