Chapter 1 什么是区块链？不是只有比特币的「账本魔法」 / What Is Blockchain? The "Ledger Magic" Beyond Bitcoin

上周五下午，班主任李老师刚收完这周的英语作业，就让生活委员小雅把没交作业的同学名单记在班级账本上。结果下周一小雅发烧请假，班长翻账本的时候发现，里面记的「没交作业」名单里居然有自己的名字——原来小雅昨天记的时候把同桌的名字和自己的搞混了，改的时候又没跟大家说，大家吵了半天，最后只能重新统计一遍，浪费了一节自习课。

Last Friday afternoon, after homeroom teacher Ms. Li collected everyone’s English homework, she asked the class treasurer Xiao Ya to write down the list of students who didn’t hand in their work in the class ledger. But when the monitor checked the ledger on Monday morning, they found their own name on the "missing homework" list — turns out Xiao Ya had mixed up her desk mate’s name with hers when she wrote it the day before, and she didn’t tell anyone when she fixed it. The class argued for a while, and in the end they had to recount everything, wasting an entire self-study period.

要是我们换一种记作业的方式：全班每个人手里都发一本一模一样的账本，每次有人交作业，就由收作业的同学在讲台上喊一声「XXX交作业了」，全班所有人都同时把这行记录写在自己的账本上。要是有人想偷偷改自己的账本，把没交作业改成已经交了，只要一核对其他同学的账本，发现只有他一个人的记录不一样，立刻就能知道他在撒谎，改的账根本不作数。这个全班人手一本、一起记账、一起核对的共享账本，就是区块链最最基础的雏形。

If we changed the way we record homework: every student in the class gets an identical ledger, and every time someone hands in their work, the student collecting the homework announces "XXX handed in their homework" at the podium, and everyone writes this record in their own ledger at the same time. If someone tries to secretly change their own ledger to mark an unsubmitted assignment as submitted, as soon as they cross-check with other students’ ledgers and find only their record is different, everyone will know they are lying, and the altered record will be invalid. This class-wide shared ledger, where everyone has a copy, keeps accounts together, and cross-checks records, is the most basic prototype of blockchain.

1.1 别再把区块链和比特币划等号啦！/ Stop Equating Blockchain with Bitcoin!

很多人第一次听到「区块链」三个字，第一反应是「哦，就是比特币那个炒币的东西」，这就像第一次听到「电」就想到「灯泡」一样，只看到了最表面、最出名的应用，却没看到背后的底层技术本身。比特币确实是区块链的第一个成功应用，但区块链能做的事情，可比比特币多太多了——它本质是一种<concept>分布式账本技术（Distributed Ledger Technology, DLT）</concept>，一种由所有参与者共同维护、没人能单独控制的「共享记账本」。

Many people’s first reaction to hearing the word "blockchain" is "Oh, that’s the stuff for trading Bitcoin", which is like hearing the word "electricity" and only thinking of "light bulbs". You only see the most famous surface-level application, but miss the underlying technology itself. Bitcoin is indeed the first successful application of blockchain, but blockchain can do far more than Bitcoin — at its core, it is a <concept>distributed ledger technology (DLT)</concept>, a "shared accounting book" jointly maintained by all participants, with no single person able to control it alone.

我们可以把区块链和比特币的关系，类比成你和你的游戏账号：区块链是那台能玩各种游戏的游戏机，比特币是第一个装在这台游戏机上、特别火的游戏，之后还能装无数个其他游戏，比如公益溯源、数字身份、供应链管理、甚至班级班费管理，这些都是跑在区块链这台「游戏机」上的新应用。

We can compare the relationship between blockchain and Bitcoin to your game account: blockchain is the game console that can run all kinds of games, and Bitcoin is the first super popular game installed on this console. After that, you can install countless other games on it, such as public welfare tracing, digital identity, supply chain management, and even class fee management — these are all new applications running on the blockchain "game console".

2008年全球金融危机爆发的时候，很多人对中心化的银行系统失去了信任：银行随便增发货币导致存款缩水、内部人员篡改账目挪用用户资金、跨境转账要等好几天还要收高额手续费……一个化名叫「<concept>中本聪（Satoshi Nakamoto）</concept>」的神秘人，在2008年10月31日发表了一篇只有9页的论文《比特币：一种点对点的电子现金系统》，首次提出了用区块链技术实现去中心化的电子货币系统，也就是比特币。2009年1月3日，比特币的「创始区块」（也就是区块链上的第一页账）被正式挖出，中本聪给密码学专家哈尔·芬尼转了10个比特币，这是比特币历史上的第一笔交易，这笔交易的记录到现在还完整地存在区块链上，任何人都可以查询。

When the 2008 global financial crisis broke out, many people lost trust in the centralized banking system: banks arbitrarily printed money leading to the shrinking of deposits, internal staff tampered with accounts to embezzle user funds, cross-border transfers took days and charged high fees... A mysterious person with the pseudonym <concept>Satoshi Nakamoto</concept> published a 9-page paper "Bitcoin: A Peer-to-Peer Electronic Cash System" on October 31, 2008, which first proposed using blockchain technology to realize a decentralized electronic currency system, that is, Bitcoin. On January 3, 2009, the "genesis block" of Bitcoin (that is, the first page of the ledger on the blockchain) was officially mined, and Satoshi Nakamoto transferred 10 bitcoins to cryptography expert Hal Finney. This was the first transaction in Bitcoin history, and the record of this transaction still exists completely on the blockchain, and anyone can query it.

> 📌 电子版互动资源：点击这里查看比特币首笔交易的区块链浏览器真实记录，看看14年前的那笔转账现在还能不能查到！ > `<interactive>比特币首笔交易链上记录查询</interactive>`

> 💡 小知识：中本聪的真实身份至今是互联网十大未解之谜之一，有人说是美国程序员，有人说是日本数学家，甚至有人说是某个大型科技公司的团队，他在2011年之后就再也没有在互联网上公开露面，就像武侠小说里做完大事就归隐的绝世高手。

> 📌 电子版侧边栏：如果你对中本聪的身份感兴趣，可以点击这里查看全球研究者对中本聪身份的10大猜想，看看你觉得最有道理的是哪个？ > `<interactive>中本聪身份猜想专题</interactive>`

1.2 区块链的三大核心魔法：去中心化、不可篡改、公开透明 / The Three Core "Magic" of Blockchain: Decentralization, Immutability, and Transparency

刚才我们用班级记账的例子，已经能大概理解区块链是什么了，但区块链之所以能成为改变世界的技术，靠的是三个刻在基因里的核心特征，我们再用你熟悉的例子一一拆解：

We have roughly understood what blockchain is through the example of class bookkeeping, but the reason why blockchain can become a world-changing technology relies on three core characteristics built into its genes. Let’s break them down one by one with examples you are familiar with:

1.2.1 去中心化（Decentralization）：没有「老大」，大家一起说了算

传统的记账方式都是中心化的：老师一个人记班级账本，银行一个人记你的存款账本，游戏公司一个人记你的游戏道具账本——这个「记账的老大」就是中心，要是这个中心出问题了，整个账本就乱了：老师记错了账，银行系统被黑了，游戏公司倒闭了，你的数据可能就没了。

The traditional way of bookkeeping is centralized: the teacher alone keeps the class ledger, the bank alone keeps your deposit ledger, and the game company alone keeps your game item ledger — this "boss who keeps accounts" is the center. If this center has a problem, the entire ledger will be messed up: if the teacher records the accounts wrong, the bank system is hacked, or the game company goes bankrupt, your data may be gone.

而区块链是去中心化的，没有单独的老大，所有人都可以参与记账，所有人的账本都一模一样，权力完全平等。还是拿班级账本举例：要是老师故意把某个没交作业的同学的名字从账本上划掉，在中心化账本里只要改老师那一本就行，但在区块链账本里，全班50个人的账本里都记着这个同学没交作业，老师改自己手里的那一本没用，一核对就露馅了。

Blockchain is decentralized, with no single boss. Everyone can participate in bookkeeping, and everyone’s ledger is exactly the same, with completely equal rights. Taking the class ledger as an example: if the teacher intentionally crosses out the name of a student who didn’t hand in their homework from the ledger, in a centralized ledger they only need to change the teacher’s copy, but in a blockchain ledger, all 50 students’ ledgers record that the student didn’t hand in their homework. The teacher changing their own copy is useless, and it will be exposed as soon as they cross-check.

`<feature>去中心化（Decentralization）：没有单一的控制者，所有参与者共同维护系统，不会因为单个节点出问题导致整个系统崩溃。</feature>`

1.2.2 不可篡改（Immutability）：改了一个人的账，没用

区块链的第二个核心特征是「不可篡改」，意思是一旦数据被记到区块链上，就几乎不可能被修改。为什么？因为要改数据，你得把超过一半人手里的账本都改了，成本高到几乎不可能实现。

The second core feature of blockchain is "immutability", which means that once data is recorded on the blockchain, it is almost impossible to modify. Why? Because to modify the data, you have to change more than half of everyone’s ledgers, and the cost is so high that it is almost impossible to achieve.

还是拿全班50

还是拿全班50个同学的例子：如果有个同学想改自己的账本，把「没交作业」改成「已交」，他不仅要改自己的账本，还得偷偷改至少25个其他同学的账本，不然一核对大家就会发现他的账本和别人不一样，他改的根本不被承认。放到真正的比特币区块链上，这个成本就高到离谱了——现在全球有超过15000个比特币全节点（就是完整存了所有比特币交易记录的电脑），要篡改比特币的交易记录，你得控制至少7500个全节点，还要重新算后面所有区块的「工作量证明」（Proof of Work, PoW），也就是得先解一道超级难的数学题，才有资格记账，算力成本至少要上亿美元，花这么多钱就为了改一笔几块钱的交易，傻子才会干。而且就算你改成了，其他人一核对链的完整性，发现所有区块的「身份证号」（哈希值）都对不上，根本不会承认你改的版本。

Still taking the example of the whole class of 50 students: if a student wants to change their own ledger to cross out "missing homework" and write "submitted", they not only have to change their own ledger, but also secretly change at least 25 other students’ ledgers. Otherwise, everyone will find their ledger is different from others when cross-checking, and their altered record will not be recognized. Put this in the context of the real Bitcoin blockchain, the cost is ridiculously high — there are