What Is Blockchain Technology 什么是区块链技术

贺丛芝

Blockchain is a mathematically designed structure to store data in a way which is almost impossible to hack or fake it out. And the technology which is used to do so， is called Blockchain Technology. The wide range of use cases of Blockchain to store all kind of valuable data in almost each & every industrial sector made this topic extremely hot nowadays. Its difficult to explain Blockchain Technology without going in details， but here， Ill try to make it as simple as possible， I Promise！

How was it born？

We cannot begin to discuss blockchain stocks without first giving a brief nod to Satoshi Nakamoto， the acknowledged inventor of the technology. On October 31 of 2008， Satoshi Nakamoto released a white paper called “Bitcoin： A Peer-to-Peer Electronic Cash System.” The document issued to the subscribers of the cryptography mailing list1 described a revolutionary technology that created the worlds first genuine peer-to-peer and decentralized monetary system.

Then， on 9th Jan， 2009， Satoshi started mining the first Bitcoins with GenesisBlock2， and thats how the Age of Cryptocurrency started， and the technology that made it happen， is what we now recognize with the word “Blockchain”. By combining Cryptography with Blockchain， Nakamoto solved the problem of double spending3 which was on the edge for decades to create digital cash. It also eliminates the need for central authority or third party to mediate electronic exchange of a currency.

Satoshi Nakamoto is an enigma， and to this day it is not known whether this is the name of a single individual or a group effort， but whats known is that blockchain technology changed the way money is handled in 2008 when it first hit the market as bitcoin. It continues to allow innovation today. So， what is a blockchain？ You dont need a ton of information about how it works to understand that you are investing in the future of data as we know it. That means everything from bank transfers （AKA money） to personal information. In essence， a blockchain is a data recording system where every link in the chain has its own data and information from the block both before and after it.

To change the data would change the entire block so it would no longer fit in the chain. To change the chain you need a whole lot of information， and theres additional protection. Each blockchain is verified many times over by independent “miners” who view and verify the information so that any changed block no longer matches every other copy of that block. In short， a blockchain is an unprecedented level of data security. Think of it as a letter （the data） that you might put in the post and send anywhere （the transfer of data）. That letter goes in a clear box， and that clear box goes in a truck full of cameras run by different people， using various sources of electricity， and all those people can see the letter. If anyone messes with the message， everyone can see it has changed.

What does blockchain do？

Almost each & every cryptocurrency-blockchains consist of five stages in a block generation process：

1. Transaction signing by a user

2. Transaction broadcasting to the network

3. Block creation by the miners

4. Block broadcasting to the network

5. Validating and adding this new block by the network-nodes to the blockchain

How secure is blockchain？

This and that， everything is correct， but is it really secure？ Specifically stating， can blockchain offer trustless environment to record private and tamper-proof blocks？ The short answer is no. 100% pure and perfect immutability does not exist， blockchain like any other web software or network， is theoretically and technically vulnerable to modify.

So， is it not any secure at all？ Again， the answer is no. As all of the nodes on a blockchain are decentrally distributed， to alter a chain， one would need to take control of more than 51% of total mathematical computing power4 and alter all of the transactional records in a distributed ledger5 within a very short space of time （e.g. Average Block Time for Bitcoin–10 minutes， Ethereum–14 seconds）. Modification is nearly impossible， which makes the network 99.99% immutable and secure. So， it is till now， this has never happened secure.

Types of blockchains

1. Public blockchains

A public blockchain， which has absolutely no access restrictions， uses Proof of Stake or Proof of Work algorithm to secure the network. Some of the popular public blockchains are Bitcoin and Ethereum.

2. Private blockchains

A private blockchain is also called “Permissioned” blockchain， as anyone cant read/write or review/audit the source code data unless one has the permission（s）/right（s） from the network administrators to do so. Usually， single organization controls this type of blockchain for their personal use. Example of popular private blockchain is Ripple.

3. Consortium blockchains

A consortium blockchain is also called “Semi-Decentralized” or “Federated” blockchain， as instead of a single organization controlling it， a number of organizations control the blockchain according to their nodes permission（s）/right（s）.     ■

區块链是一种基于数学方法设计的数据存储结构，几乎不可被非法入侵，也无法伪造。用这种方法来存储数据的技术就叫作区块链技术。区块链应用广泛，几乎各行各业都用其存储各种重要数据，该技术因此时下广受热议。不细说很难说清区块链技术是怎么回事，我还是保证尽量讲得通俗易懂。

区块链是怎么诞生的？

在讨论区块链技术股的行情之前，我们先来简单认识下公认的区块链技术发明者中本聪。2008年10月31日，中本聪发布了一篇白皮书，题为《比特币：一种点对点电子现金系统》。这篇论文被发送给密码学邮件组论坛的所有成员，文中描述了一项具有革命性的技术，由此诞生了世界上第一个真正点对点、去中心化的货币系统。

随后，在2009年1月9日，中本聪开始用创世区块来挖掘第一批比特币，加密货币时代就这样开始了。而让这一切成为现实的技术，就是我们现在所熟知的“区块链”。中本聪将密码学与区块链相结合，解决了双重支付问题。这是数十年来创造数字货币一直悬而未决的问题。同时，电子货币交易也不再需要通过中心化的权威机构或第三方来完成。

中本聪一直是一个谜，他究竟是一个人，还是一个团队，至今尚未可知。但我们知道的是，2008年，区块链技术以比特币的形式首次进入市场，就改变了货币的流通方式。如今，这项技术仍然在不断创新。那么，区块链到底是什么？即使不用通过大量的信息了解它的运作方式，你也能够明白，你是在投资数据的未来，这是我们所知道的。这涵盖了从银行转账（也就是货币）到个人信息等所有数据。从本质上讲，区块链就是一个数据记录系统。在这个系统中，链条上的每个区块都有自己的数据和信息，这些数据和信息来自它前面和后面的区块。

一旦数据有所改动，整个区块就会发生变化，与链条也就不再匹配。而要改变链条，则需要大量的信息，并且还要突破其他保护措施。每个区块链都由独立的“矿工”进行多次验证。这些“矿工”查看并验证信息，任何一个区块，只要经过修改，就会与它的其他副本不相吻合。简单来说，区块链使数据安全性达到了前所未有的高度。试著把它想象成一封信（数据），你可以通过邮局，把它发送到任何地方（数据传输）。这封信装在一个透明的盒子里，这个盒子放在一辆装满摄像机的卡车里，摄像机由不同的人使用不同的电源操作，所有人都能看到这封信。如果有人篡改这封信，每个人都能发现它被改动了。

区块链可以做什么？

几乎每一个加密货币区块链都要经过以下五个步骤来生成一个区块：

1. 一名用户进行交易签名

2. 将交易广播到网络

3. 矿工创建区块

4. 将区块广播到网络

5. 网络节点验证新的区块并将其添加到区块链中

区块链有多安全？

说了这么多，都没错，但是区块链真的安全吗？更确切地说，区块链记录私有和防篡改区块的环境会不可靠吗？答案是否定的。但百分之百完全没有变化是不可能的。无论从理论上还是技术上来讲，区块链和其他任何软件或网络一样，都很容易被修改。

那么，它一点也不安全吗？当然，答案也是否定的。区块链上所有节点都是去中心化分布的，要想更改区块链，须掌控全网数学算力的51%以上，在极短的时间内（比如，比特币平均每个区块生成时间是10分钟，以太坊为14秒）篡改分布式账本上所有交易数据。这几乎是不可能实现的，也就是说，网络99.99%是不可变且安全的。所以，区块链很安全，起码到现在为止，从没出过什么事。

区块链的分类

1. 公有区块链

公有区块链没有访问限制，采用权益证明或工作量证明算法来保护网络。比特币和以太坊都是典型的公有区块链。

2. 私有区块链

私有区块链也被称为“许可”区块链。除非获得网络管理员的许可/权限，否则任何人都不能读/写或检查/审计源代码数据。通常，私有区块链由某个组织控制，仅供内部使用。瑞波币就是一种私有区块链。

3. 联盟区块链

联盟区块链又称“半去中心化”或“联合”区块链。它不是由某个组织控制，而是由多个组织根据各自节点的许可或权限来控制。                      □

（译者为“《英语世界》杯” 翻译大赛获奖者）