What Is Blockchain Technology 什么是區塊鏈技術

賀叢芝

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）.? ? ?■

區塊鏈是一種基于數學方法設計的數據存儲結構，幾乎不可被非法入侵，也無法偽造。用這種方法來存儲數據的技術就叫作區塊鏈技術。區塊鏈應用廣泛，幾乎各行各業都用其存儲各種重要數據，該技術因此時下廣受熱議。不細說很難說清區塊鏈技術是怎么回事，我還是保證盡量講得通俗易懂。

區塊鏈是怎么誕生的？

在討論區塊鏈技術股的行情之前，我們先來簡單認識下公認的區塊鏈技術發明者中本聰。2008年10月31日，中本聰發布了一篇白皮書，題為《比特幣：一種點對點電子現金系統》。這篇論文被發送給密碼學郵件組論壇的所有成員，文中描述了一項具有革命性的技術，由此誕生了世界上第一個真正點對點、去中心化的貨幣系統。

隨后，在2009年1月9日，中本聰開始用創世區塊來挖掘第一批比特幣，加密貨幣時代就這樣開始了。而讓這一切成為現實的技術，就是我們現在所熟知的“區塊鏈”。中本聰將密碼學與區塊鏈相結合，解決了雙重支付問題。這是數十年來創造數字貨幣一直懸而未決的問題。同時，電子貨幣交易也不再需要通過中心化的權威機構或第三方來完成。

中本聰一直是一個謎，他究竟是一個人，還是一個團隊，至今尚未可知。但我們知道的是，2008年，區塊鏈技術以比特幣的形式首次進入市場，就改變了貨幣的流通方式。如今，這項技術仍然在不斷創新。那么，區塊鏈到底是什么？即使不用通過大量的信息了解它的運作方式，你也能夠明白，你是在投資數據的未來，這是我們所知道的。這涵蓋了從銀行轉賬（也就是貨幣）到個人信息等所有數據。從本質上講，區塊鏈就是一個數據記錄系統。在這個系統中，鏈條上的每個區塊都有自己的數據和信息，這些數據和信息來自它前面和后面的區塊。

一旦數據有所改動，整個區塊就會發生變化，與鏈條也就不再匹配。而要改變鏈條，則需要大量的信息，并且還要突破其他保護措施。每個區塊鏈都由獨立的“礦工”進行多次驗證。這些“礦工”查看并驗證信息，任何一個區塊，只要經過修改，就會與它的其他副本不相吻合。簡單來說，區塊鏈使數據安全性達到了前所未有的高度。試著把它想象成一封信（數據），你可以通過郵局，把它發送到任何地方（數據傳輸）。這封信裝在一個透明的盒子里，這個盒子放在一輛裝滿攝像機的卡車里，攝像機由不同的人使用不同的電源操作，所有人都能看到這封信。如果有人篡改這封信，每個人都能發現它被改動了。

區塊鏈可以做什么？

幾乎每一個加密貨幣區塊鏈都要經過以下五個步驟來生成一個區塊：

1. 一名用戶進行交易簽名

2. 將交易廣播到網絡

3. 礦工創建區塊

4. 將區塊廣播到網絡

5. 網絡節點驗證新的區塊并將其添加到區塊鏈中

區塊鏈有多安全？

說了這么多，都沒錯，但是區塊鏈真的安全嗎？更確切地說，區塊鏈記錄私有和防篡改區塊的環境會不可靠嗎？答案是否定的。但百分之百完全沒有變化是不可能的。無論從理論上還是技術上來講，區塊鏈和其他任何軟件或網絡一樣，都很容易被修改。

那么，它一點也不安全嗎？當然，答案也是否定的。區塊鏈上所有節點都是去中心化分布的，要想更改區塊鏈，須掌控全網數學算力的51%以上，在極短的時間內（比如，比特幣平均每個區塊生成時間是10分鐘，以太坊為14秒）篡改分布式賬本上所有交易數據。這幾乎是不可能實現的，也就是說，網絡99.99%是不可變且安全的。所以，區塊鏈很安全，起碼到現在為止，從沒出過什么事。

區塊鏈的分類

1. 公有區塊鏈

公有區塊鏈沒有訪問限制，采用權益證明或工作量證明算法來保護網絡。比特幣和以太坊都是典型的公有區塊鏈。

2. 私有區塊鏈

私有區塊鏈也被稱為“許可”區塊鏈。除非獲得網絡管理員的許可/權限，否則任何人都不能讀/寫或檢查/審計源代碼數據。通常，私有區塊鏈由某個組織控制，僅供內部使用。瑞波幣就是一種私有區塊鏈。

3. 聯盟區塊鏈

聯盟區塊鏈又稱“半去中心化”或“聯合”區塊鏈。它不是由某個組織控制，而是由多個組織根據各自節點的許可或權限來控制。? ? ? ? ? ? ? ? ? ? ? □

（譯者為“《英語世界》杯” 翻譯大賽獲獎者）