推荐序2 See the past, present and be the future yourself
（回溯过去，看见现在，参与未来）
Vitalik Buterin Founder of Ethereum
（以太坊创始人）
When I first discovered blockchain technology through Bitcoin in 2011, it took some time for me to realize the full potential. Like many others at the time, the aspect that stood out to me the most was Bitcoin the currency - a currency which I initially rejected as doomed to failure, as it was not backed by anything and had no underlying value. After hearing about it again a few weeks later, I realized that there was genuine potential, and so I started actively exploring, reading, earning, spending, and writing about Bitcoin. However, it took until visiting the blockchain community in Israel in late 2013 before I saw the fundamental truth that would eventually guide me to creating Ethereum: it was Bitcoin's underlying technology, the blockchain, that was the larger story, and it has applications that stretch far beyond peer-to-peer currency. Crowdfunding, insurance, financial contracts, identity management, supply chains, land registries and many more applications could be affected, and someone, somewhere comes up with a new way that blockchain technology can improve our lives every week.
（当我在2011年第一次通过比特币发现了它背后的区块链技术时，我花了一些时间才意识到它的潜力。就像那时候的许多其他人一样，起初出现在我眼前的是作为货币的比特币，一种被我认定为必然失败的货币，因为它没有任何内在价值。但是，几周以后，我意识到它具有的真实潜力，也因此我开始积极地探索、阅读、编写、获取和花销比特币和它所相关的一切。然而，直到我2013年在以色列访问了区块链社区，我才看到了最终指引我走向创造以太坊的根本性真相：比特币的底层技术——区块链，有着更为广阔的未来，并且有着远远超出点对点货币的大量应用场景。众筹、保险、金融合约、身份管理、供应链、土地登记，以及除此之外更大更多的用武之地，而地球上每周都有人在某些地方创造出了新的区块链应用场景，来提升我们生活的品质。）
Decentralization and cryptography, two fundamental building blocks of Bitcoin and Ethereum-like systems, are not new. Decentralized networks such as BitTorrent have existed since the early 2000s, and cryptographers, mathematicians and software engineers have been working on increasingly advanced protocols in order to get stronger and stronger privacy and authenticity guarantees out of various systems, ranging from electronic cash to voting to file transfer and storage, for the last thirty years. However, the innovation of the blockchain - or, more generally, the innovation of public economic consensus - by Satoshi Nakamoto in 2009 proved to be the one missing piece of the puzzle that brought together both “strands” of research, and single-handedly gave the industry a giant leap forward.
（去中心化及密码学，作为类似于比特币与以太坊这样的系统的两大基础性模块，并不是新鲜技术。类似于BitTorrent（BT下载）的去中心化网络早在2000年初就已经存在了，而密码学家、数学家及软件工程师也已经努力了近三十年，致力于不断提升协议的先进性，从而实现从电子现金到投票再到文件传输存储等各类系统更强的隐私性、可信度保障。然而，区块链的创新，或者通俗地来讲就是中本聪在2009年所证明的公共经济共识的创新，才是那一片原本缺失的线索，它将去中心化与密码学这两股研究方向拧在了一起，然后“抽一鞭子”让整个行业向前跃进了一大步。）
The ideological environment seemed to almost snap into place: the great financial crisis in 2008 spurred growing distrust in mainstream finance, including both corporations and the governmental institutions that are normally supposed to regulate them, and was the initial spark that drove many to seek out alternatives, and Edward Snowden's revelations in 2013 were the icing on the cake. Although so far blockchain technologies specifically have not seen mainstream adoption as a result, the underlying spirit of decentralization, and building applications that put the user in charge, to a substantial degree has: applications ranging from Apple's phones to WhatsApp have started building in forms of encryption that are so strong that even the company writing the software and managing the servers cannot break it. On another side, the advent of “sharing economy 1.0” is increasingly showing signs of failure to fulfill what many had originally seen to be its promise: rather than simply cutting entrenched and oligopolistic intermediaries out, giants like Uber are simply replacing the middleman with themselves, and in some cases not particularly doing a better job of it.
（而意识形态的大环境似乎也恰到好处：2008年的金融危机刺痛了人们对于主流金融不信任的神经，也导致人们对于金融公司以及理应监管它们的政府机构失去了信心，而这也擦出了人们去寻找替代品的最初火花。2013年爱德华·斯诺登的启示则更是为原本的不信任雪上加霜。尽管到目前为止，区块链技术本身并没有出现主流的应用，但它所蕴含的去中心化精神以及将用户作为应用程序主体的程序开发思路已经深入人心：从苹果手机到WhatsApp，都开始通过用户加密的方式设计程序，从而实现即使是负责程序开发和管理的公司自己也无法破解用户设置的密码。从另一个方面而言，诞生不久的所谓“共享经济1.0”正在逐渐透露出失败的迹象，因为它们难以兑现最初的承诺：与其简单地去除根深蒂固的寡头中介，像Uber这样的巨头反而选择了仅仅将原本的中介换成了它们自己，而在某些情况下也并没有做得比它们的前任更好。）
Blockchains, and the umbrella of related technologies that I have collectively come to call “crypto 2.0”, provides an attractive fix: rather than simply hoping that the parties we interact with behave honorably, we build technological systems that inherently build the desired properties into the system, in such a way that it will keep functioning with the guarantees that we expect even if many of the actors involved are corrupted. All transactions would come with auditable trails of cryptographic proofs, decentralized peer-to-peer networks would be used to reduce reliance on any single server, public key cryptography could create a notion of portable user-controlled identities, and entire financial systems could be built in such a way that there is no single central party that needs to hold custody over other people's funds, and that other people need to trust not to go bankrupt, try to cheat them, or run away with their funds.More advanced kinds of math, including ring signatures, homomorphic encryption and zero-knowledge proofs, would to guarantee privacy, allowing users to put all of their data in the open in such a way that certain properties of it can be verified, and even computed on, but without actually revealing any private details.
（区块链及与其相关的技术被我总称为“数字货币2.0”，它们提供了一个吸引人的解决方案：相比于仅仅寄希望于与我们产生互动的对手方行为良好，我们建立的技术系统将我们所需的属性先天性地嵌入系统当中，从而实现即便是系统中的许多参与方是行为不良的，系统也仍然能够保证像我们所希望的那样正常运转。所有的交易都会以密码学证明的方式经历一次审计流程，去中心化的点对点网络将会被用于减少对于单一服务器的依赖，公钥加密能够创造一个便携的由用户控制的身份概念，整个金融系统将会被建立在一个新的体系上，在这种体系中，没有一个单独的中心化组织需要对所有其他人的资金进行监管，也没有一个单独的组织需要被相信是不会破产的，用户也不用担心被欺诈，或是遭遇卷款跑路。更为先进的数学方法，包括环状签名、同态加密及零知识证明体系，将会被用于保障私密性，保证了用户将他们所有的数据都公开并在针对数据的一些属性被验证、计算的前提下不用揭露自身隐私的那一部分细节。）
What has impressed me the most about the last five years is just how far the technology has come, and how far the industry has evolved. From 2010 to 2013, there was a lot of excitement about the technology and its potential, and there were many startups being formed to try to build something on it. However, the technology was still in its early phase, and discussion about practical applications was rare; many startups would literally include as part of their pitch deck to venture capital firms an assumption that the bitcoin price would increase by a factor of four every year, and in some cases that was the closest thing to a business model that these companies had to speak of. In 2014, that model suddenly, but inevitably, began to falter, as the price went in the exact opposite direction to the three years before, and so entrepreneurs looking to change the world with blockchain technology began to look to a radical new strategy to earn their revenue: finding actual use cases, and working with actual customers and traditional enterprise to try to bring those applications from a concept in their heads, to a proof-of-concept written in code, and finally to a product that would be used by millions of people. And it is not just startups that are getting involved;despite the anti-bank sentiment of many of the technology's earliest advocates, today it is the banks that are among the most prominent developers of blockchain applications. Blockchain technology is growing up, and is finally coming of age.
（于我而言，最让我印象深刻的是过去这五年来这项技术的发展速度，以及这个行业所进化的速度。从2010到2013年，关于区块链技术有许多令人激动和充满潜力的进步，许多初创公司正在逐渐形成并且尝试着在此技术之上建立一些新的东西。然而，这项技术仍然停留在它的早期阶段，关于实践应用的讨论仍然比较稀少。许多初创公司仅仅将“区块链”放入他们对风投公司的融资演讲稿中，并且假设着比特币的币价每年都会上涨四倍，而在某些情况下币价与这些公司的商业模式密切相关。2014年，这些模式突然间（也不可避免）开始走得颤颤巍巍，因为比特币的价格完全向三年前相反的方向发展。于是那些致力于使用区块链技术改变世界的企业家们，开始寻找一种激进的新策略来赚取他们的收益：寻找真实的应用场景，并且与真实的客户以及传统企业合作，从而将他们的应用从脑袋里的概念转化为证明概念的代码，最终成为能够被成千上万人使用的产品。事实上，参与其中的也并不仅仅是初创公司，连最初区块链技术倡导者们认为反对该技术的银行，今天反而成为了区块链应用开发的中坚力量。区块链技术正在成长，也终于成长到了一个新的时代。）
Personally, at my age of 22, I do not have decades of experience in any industry, except perhaps the twelve years which I have spent writing code, the first six of which largely consisted of writing computer games that I would later spend thousands of hours playing myself; hence, I am not the person who will be working out the finer details of how blockchain-based timestamping can improve transparency in the supply chain, or how smart contracts can simplify the archaic processes that are currently being used in trade finance, or how decentralized clearing networks based on consortium chains can create a more egalitarian and efficient alternative to the central clearing parties that dominate many financial markets today.
（我今年22岁，除了12年的编写代码经验外，我并没有几十年的行业经验，而这12年中的前6年里的大多数时间我都在写电脑游戏以及花上千小时玩它们；因此，我也不是一个能够出色地解释基于区块链的时间戳，能够如何增加供应链的透明度的人，也不能完美地描述智能合约如何能够简化当前贸易金融中的陈旧流程，亦或基于联盟链的去中心化清算网络如何能够创造一个更为公平、高效的替代品来替换当前主导金融市场的中心化清算方式。）
Rather, the contribution that I aimed to make to society with Ethereum is the opposite: create a highly generalized platform that includes a highly flexible programming language, and so can be employed for any application in any industry with maximum ease. We would deal with the challenge of making the underlying blockchain layer as scalable, efficient, generalized and secure as possible, giving application developers the freedom to focus on building the business logic of their application itself. At the time that I originally came up with the idea for Ethereum, I expected that it would fail; it seemed too good to be true, and so I thought that within a week I would get five smart cryptographers replying back to the email containing my whitepaper, explaining to me some very good mathematical reasons why it could not work. And yet, that never happened; instead, after a year and eight months of development, the project launched, and the blockchain has been running smoothly ever since, with thousands of users, tens of thousands of transactions per day and over a hundred applications either under development or already deployed.
（然而，我所致力的通过以太坊向社会所做的贡献却恰恰与此相反：以太坊致力于创造一个高度通用化的平台，它包含了高度灵活的编程语言，从而不仅实现了各种产业的适用性，也最大程度简化了应用过程。我们所需要做的是处理好来自于区块链层上关于延展性、效率、通用性以及安全性的挑战，从而给应用开发者提供足够的自由空间以专注于完成他们自身商业逻辑的构建。在我最初想到以太坊这个点子的时候，我是觉得它会失败的，因为它看起来太完美了，从而变得不那么真实，于是我认为在一周以内就会有5位聪明的密码学家回复我以太坊白皮书的邮件，并通过一些很好的数学原理向我解释为什么它不会成功。然而最终这并没有发生，取而代之的是，经过一年零八个月的开发，这个计划上线了，并且它的区块链从那以后一直被很顺畅地运行着。链上聚集了上千名用户，每日上万笔的交易，以及超过一百个正在开发或已经上线的应用。）
The concept that Clearmatics CEO Robert Sams so correctly summarizes as“decentralized automation” - not just a decentralized ledger that would store the final result of processes that are otherwise centralized, but a process re-engineering effort where the entire lifecycle of a financial trade, or a land ownership record, or an identity record, could be run on a decentralized platform, stands the chance to reduce greatly what Ronald Coase has called “transaction costs” - the bureaucratic and economic costs of managing an interaction, figuring out the details of the legal contract, making sure that the counterparty is trustworthy, and recording the results, that are the reason why so many people today prefer to instead interact by congregating into large, centralized firms. As a result, we may see an economy in the 21st century that in some ways resembles that of the 18th: one where, instead of a single company selling insurance as a product, we insure each other, instead of a central party clearing financial trades and payment transactions, such operations are conducted directly peer-to-peer, and even functions such as evaluating creditworthiness and reputation, quality control, and tracking property rights are done in a much more decentralized way - but at the same time, where the extreme efficiencies of 21st century information technology mean that we can have the benefits of running our society in this way without many of the costs.
（Clearmatics的CEO Robert Sams将这个概念很正确地总结为“去中心自动化”——不仅仅是一个用于存储过程结果的去中心化的账本，而是一个经过过程重构了的多用途去中心化平台。它通过去中心化所重构的过程包含了金融交易的全流程、土地所有权登记的全流程以及身份记录的全过程。经过它的过程重构将实现Ronald Coase所谓的“交易费”的大大削减，而这“交易费”指的是为了明晰法律合同的细节、确保对手方的可信、记录各种结果所进行的官僚化的管理互动而产生的经济开支。也因此，人们比起与聚集化、中心化的大公司互动，更愿意选择一个去中心化的互动模式。结果就是，我们或许能够看到21世纪的经济形态更像18世纪的组织形态：一种以互相担保而取代单一公司出售保险产品；以点对点的交易形式取代第三方中心化清算金融交易和支付；甚至于以一种更为去中心化的方式来评价信任度和名誉、完成质量控制、实现产权跟踪。而同时，21世纪信息技术的极度高效也意味着我们能够以很低的消耗来实现这样的社会形态。）
Of course, it is decidedly not the case that absolutely every industry will become more decentralized, or even that those industries that will become more decentralized will do so through blockchain technology specifically. Every industry is its own special case, and it is, for example, hard to see how the construction of a billion-dollar rocket going to Mars could be economically managed by a decentralized automaton or smart contract running on Ethereum. However, the possibilities are many, and 2016 is the year where the initial proof of concepts for real-world use cases are starting to be developed and tested. 2017 will be the year where, just as is the case in any industry, over two thirds of them will inevitably fail, but the remaining third will be expanded further into real-world applications reaching millions of users - and that is when the next phase will begin.
（诚然，必然不是所有行业都会变得更为去中心化，而那些会变得更为去中心化的行业也会需要通过更为个性化的区块链结构来实现去中心化。因为每一个行业都是自身的一个特例，也因此，举例来说，就是很难去预测如何通过在以太坊上运行的去中心自动化或者智能合约，来使得建造一个几十亿美元的火箭并把它发射到火星这件事变得经济实惠。然而可能性依旧很多，同时，2016年，也正是现实世界应用场景的概念性证明开发和测试开始的一年；2017年，在某些行业，将会有2/3的应用场景不可避免地失败，但剩下的1/3将会进一步扩张成为现实世界的实用性应用，并达到几百万的用户数量，而那也会是下一阶段的开始。）
I hope that you enjoy reading about the past, present and future of what blockchain technology has to offer, and that this book will inspire you to become part of that future yourself.
（我希望你会享受阅读这本关于区块链所带来的过去、现在和未来的书，并且我相信这本书将会启发你，使你亲自成为未来的一部分。）
April 24th 2016
（2016年4月24日）