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

區(qū)塊鏈是怎么誕生的？

在討論區(qū)塊鏈技術股的行情之前，我們先來簡單認識下公認的區(qū)塊鏈技術發(fā)明者中本聰。2008年10月31日，中本聰發(fā)布了一篇白皮書，題為《比特幣：一種點對點電子現(xiàn)金系統(tǒng)》。這篇論文被發(fā)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(tǒng)。

隨后，在2009年1月9日，中本聰開始用創(chuàng)世區(qū)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(xiàn)實的技術，就是我們現(xiàn)在所熟知的“區(qū)塊鏈”。中本聰將密碼學與區(qū)塊鏈相結(jié)合，解決了雙重支付問題。這是數(shù)十年來創(chuàng)造數(shù)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(gòu)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(qū)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(chuàng)新。那么，區(qū)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(shù)據(jù)的未來，這是我們所知道的。這涵蓋了從銀行轉(zhuǎn)賬（也就是貨幣）到個人信息等所有數(shù)據(jù)。從本質(zhì)上講，區(qū)塊鏈就是一個數(shù)據(jù)記錄系統(tǒng)。在這個系統(tǒng)中，鏈條上的每個區(qū)塊都有自己的數(shù)據(jù)和信息，這些數(shù)據(jù)和信息來自它前面和后面的區(qū)塊。

一旦數(shù)據(jù)有所改動，整個區(qū)塊就會發(fā)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(qū)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(qū)塊，只要經(jīng)過修改，就會與它的其他副本不相吻合。簡單來說，區(qū)塊鏈使數(shù)據(jù)安全性達到了前所未有的高度。試著把它想象成一封信（數(shù)據(jù)），你可以通過郵局，把它發(fā)送到任何地方（數(shù)據(jù)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(fā)現(xiàn)它被改動了。

區(qū)塊鏈可以做什么？

幾乎每一個加密貨幣區(qū)塊鏈都要經(jīng)過以下五個步驟來生成一個區(qū)塊：

1. 一名用戶進行交易簽名

2. 將交易廣播到網(wǎng)絡

3. 礦工創(chuàng)建區(qū)塊

4. 將區(qū)塊廣播到網(wǎng)絡

5. 網(wǎng)絡節(jié)點驗證新的區(qū)塊并將其添加到區(qū)塊鏈中

區(qū)塊鏈有多安全？

說了這么多，都沒錯，但是區(qū)塊鏈真的安全嗎？更確切地說，區(qū)塊鏈記錄私有和防篡改區(qū)塊的環(huán)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(qū)塊鏈和其他任何軟件或網(wǎng)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(qū)塊鏈上所有節(jié)點都是去中心化分布的，要想更改區(qū)塊鏈，須掌控全網(wǎng)數(shù)學算力的51%以上，在極短的時間內(nèi)（比如，比特幣平均每個區(qū)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(shù)據(jù)。這幾乎是不可能實現(xiàn)的，也就是說，網(wǎng)絡99.99%是不可變且安全的。所以，區(qū)塊鏈很安全，起碼到現(xiàn)在為止，從沒出過什么事。

區(qū)塊鏈的分類

1. 公有區(qū)塊鏈

公有區(qū)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(wǎng)絡。比特幣和以太坊都是典型的公有區(qū)塊鏈。

2. 私有區(qū)塊鏈

私有區(qū)塊鏈也被稱為“許可”區(qū)塊鏈。除非獲得網(wǎng)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(shù)據(jù)。通常，私有區(qū)塊鏈由某個組織控制，僅供內(nèi)部使用。瑞波幣就是一種私有區(qū)塊鏈。

3. 聯(lián)盟區(qū)塊鏈

聯(lián)盟區(qū)塊鏈又稱“半去中心化”或“聯(lián)合”區(qū)塊鏈。它不是由某個組織控制，而是由多個組織根據(jù)各自節(jié)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）