Undeniably, “blockchain” is such a buzzword that almost everyone heard of and that almost every business claimed to have something to do with it. Sadly, though mostly talked, “blockchain” is least understood. Most people do not understand what blockchain stands for, let alone how it works, and some alleged “applications” of blockchain turn out to be brazen fraud. Make no mistake, blockchain is a genuine and legitimate technology that can change our life, yet it is too complicated for the authors to thoroughly explain the complex algorithms and mechanisms that back up blockchain in this Article. For us legal and business professionals, however, it is necessary to have a general idea of what blockchain is, how it works, and how it is regulated.
当下,区块链毫无疑问是一个热门词汇,几乎每一个人都听说过,且每个公司都声称与之有关。遗憾的是,虽然人人都听说过,但很少有人真正懂区块链。绝大部分人其实并不知道区块链是什么,更遑论区块链的原理,甚至有些“攀附”区块链的“应用”则被证明是赤裸裸的骗局。但请不要误会,区块链是一种能够改变我们生活的真实技术,但其又过于复杂,以至于作者在本文中绝无可能将区块链技术所基于的算法及运作机制解释清楚。不过幸运的是,对于商业及法律专业人士而言,能够了解区块链的概念、原理及相关法律规则,就已足够。
What is blockchain? The simplest definition of blockchain is that it is a decentralized digital ledger of transactions that is distributed across millions of computers (each a “node”). However, in contrast to the ordinary storage of a ledger, a blockchain ledger is stored on several thousand computers connected to a common network via the Internet. Each such computer contains a complete and identical history of every transaction beginning with the first transactions that were processed into the first “block” on that blockchain[1]. Moreover, the concept of “block” may be abstract and intimidating, but such “blocks” are really nothing more than a convenient way to aggregate transactions into larger batches for processing purposes.
区块链是什么?其最简单的定义是,一个分布于数以百万计的计算机(每一个计算机称为一个“节点”)中的去中心化的电子账本。与传统的账本不同的是,区块链“账本”存在于通过互联网相连接的成千上万的电脑中。每一台这样的电脑都存储有完整且完全相同的,记录着从第一笔交易被计入第一个“区块”开始的所有交易记录[注1]。“区块”这一概念虽然听起来十分抽象,但简而言之,只是一种将多笔交易合并成为一个便于处理的批量交易的简称。
Blockchain is by no means a new thing, although at its inception it was not called the “blockchain”, or rather, the “chain of blocks”. The first work on a cryptographically secured chain of blocks was described in 1991 by Stuart Haber and W. Scott Stornetta.[2] They wanted to implement a system where document timestamps could not be tampered with. In 1992, Bayer, Haber and Stornetta incorporated Merkle trees to the design, which improved its efficiency by allowing several document certificates to be collected into one block. Blockchain was first conceptualized by a person (or a group of people) known as Satoshi Nakamoto in 2008 in his whitepaper about Bitcoin, although Nakamoto did not actually mention the word “blockchain” in the whitepaper. Nakamoto improved the design in an important way using a Hashcash-like method to add blocks to the chain without requiring them to be signed by a trusted party.
区块链技术并不是一项新生事物,尽管在其诞生之时并没有被称为“区块链”,而是叫做“区块之链”。有关加密区块链的研究成果最早由Stuart Haber及W. Scott Stornetta[注2]于1991年发表。他们的初衷是为了创造一个文件时间戳无法被篡改的系统。Bayer,Haber及Stornetta于1992年将默克尔树(Merkle Tree)整合到区块链的设计之中,通过将多个文件证书集合到一个区块中,提升了区块链的效率。目前意义的“区块链”的概念最早由一位叫中本聪(也可能是以此为代称的组织)在其2008年发表的有关比特币的白皮书中提出,尽管中本聪当时并没有明确提及“区块链”这一词。通过使用哈希函数的模式来增加“链条”上的“区块”,从而去除对可信第三方的依赖,中本聪极大地改进了区块链的设计。
How does blockchain work? The technical aspects of the way blockchain works is far too complicated for people without technical background to understand. It is possible, however, to understand how blockchain works without understanding the technical nitty gritty, by comparing a transaction done via blockchain to a transaction done via checks.
区块链是如何工作的?区块链的技术原理对于没有技术背景的人而言十分艰涩难懂,但我们并不需要了解艰涩的技术术语理,而是可以将区块链交易类比为通过支票进行的交易,来帮助我们理解区块链的工作原理。
Since the most fundamental use of blockchain is to track transfer of virtual currency (such as Bitcoin), let us expand the “ledger” notion mentioned above, and think of a ledger that records the transfer of Bitcoin from the transferor to the transferee. Let us imagine that you need to pay one dollar to your friend, Tom. In the real world (a centralized world), if you pay by check, you and Tom basically have to go through the following steps: 1) write a check; 2) sign the check; 3) Tom receives the check and has the check verified at a financial institute; 4) the financial institute clears the check and Tom receives the money. A blockchain transaction goes through a similar and comparable process. In order to transfer a Bitcoin to Tom, the following steps are necessary: first, you will have to generate the computer code that is necessary to provide all of the information for the transaction (this is analogical to writing a check); second, you will have to input a private key that corresponds to the public address on the blockchain (signing the check); third, you will have to broadcast the transaction so it can be received by the nodes running the blockchain protocol and these nodes can continue to propagate the transaction through out the entire network of nodes (verifying the check); and last, miners bundle up transactions into blocks of aggregated transactions and append each block to the previous block, ensuring all of the nodes have a current immutable history of all transactions on the blockchain (clearing the check). The process may seem far more complicated and lengthier compared to an ordinary transaction, however the entire process can be completed within a second. From such illustration of a blockchain transaction, we can see that blockchain works without a centralized trusted party (the financial institute in the real-world example) to authenticate the transaction, and therefore puts our trust into mathematics and computing, which are much less prone to errors. This is indeed the underlying notion of all blockchain applications mentioned below.
由于区块链的最基本的应用就是记录虚拟货币(例如比特币)的流转,我们进一步延伸上文提出的“账本”概念,并可以将其想象成一个记录比特币流转的电子账本。试想一下,如果你需要向你的朋友支付一元,在真实世界(中心化的世界)中,如果你通过支票来完成支付,难么你和你的朋友需要进行以下流程:1)在支票中填入交易相关信息;2)在支票上签名;3)你的朋友收到支票后,将支票在金融机构进行验证;4)金融机构承兑该支票,你的朋友收到钱。而通过供应链完成的支付需要的流程基本相同:首先,你需要编写一段载有所有交易信息的计算机代码(这可类比于在支票上填写交易信息);其次,你需要在交易中插入一个能够对应到区块链中一个公开地址的密钥(在支票上签名);再次,你需要向网络中运行该区块链协议的所有节点公告该交易信息,此后这些节点会同时在整个网络中传播该交易信息(验证支票);最后,“矿工”会将交易批量打包成区块并将该区块与前一区块相连接,从而确保整个区块链中都有一份相同、完整且不可被篡改的交易记录(支票清算)。虽然上述交易过程看似远比真实世界中的交易要复杂和冗长,但实际上上述全过程可在一秒钟之内全部完成。通过上述对区块链交易的介绍,我们可以看到区块链交易中并不需要借助具有公信力的中央机构(例如真实世界中的银行)来验证该等交易,而是将基于对几乎不会犯错的计算机和算法的信任。这也是下文所述的所有区块链技术应用的基础。