2017, Year of bitcoin

2016 year 12 month 31 Japan , The price of bitcoin is only 968 dollar . recently , In some markets , The value of bitcoin has broken through 2 Thousands of dollars . Now a bitcoin is worth more than a pound of gold , At the moment, a pound of gold is worth 1.8 Around ten thousand dollars , And bitcoin seems likely to set a new currency record in a short time . Because of its volatility , Investors need to be cautious .

Review bitcoin's 2017, from 1000 Dollar to 10000 dollar , Bitcoin is using 11 months . And from 10000 Dollar to 20000 dollar , It took only half a month . In this year , The market value of bitcoin has risen more than 2000%. Here's the table , It shows how long it takes bitcoin to break through the thousand yuan mark each time :


picture source : The Internet

By the end of Xiaobian query , The price of bitcoin has exceeded 20000 dollar ( Before going to press , Bitcoin prices have fallen again 2 Thousands of dollars ):


picture source : The Internet

According to the statistics of Bloomberg , at present , The market value of bitcoin has exceeded 1670 Billion dollars , More than Boeing 、 Big international companies like McDonald's , More than S & P 500 In index 95% Shares . Looking back at the past year , Bitcoin prices have soared nearly tenfold .

picture source : Bloomberg

Virtual currencies like bitcoin are mostly unregulated , And bypassing the traditional banking system . Its sharp rise worries regulators around the world .2017 year 9 month , China has banned the launch of new virtual currencies , And shut down the virtual currency exchange . Chinese official sources say , This is to prevent bitcoin secondary market transactions from triggering " Uncontrollable market risk 、 Financial risk and social risk ", Because the Chinese authorities found this virtual currency “ It has become a tool for pyramid selling and illegal fund-raising ”. After the previous , Bitcoin's international trade is also in a violent shock . But after that , Bitcoin prices are soaring against the wind , More and more unstoppable .

This article will start with bitcoin , Explain bitcoin and the blockchain technology behind it in detail .

Bitcoin has a big start

With the development of information technology , People's lives are gradually networked , Digitization . As a result, profound changes have taken place in human society . The exploration of digital currency , It's against this background that it came into being . In fact, the related research was in the 1980s and 1990s , He began .

In the exploration and practice of digital currency , Bitcoin is by far the best performing one . When it comes to the origin of bitcoin , I have to talk about a slightly mysterious group : Password punk (CypherPunk). This group is a loose alliance of cryptogenists . In the innovation of bitcoin , A lot of the contributions of code punk members .

Cryptopunk itself is the earliest disseminator of digital currency , In its email group , Common discussions about digital currency , And put some ideas into practice . Before bitcoin , There are a lot of failed attempts . Here's a brief list of previous pathfinders .

Adam · Baker, (Adam Back) He's a British cryptographer ,1997 year , He invented hash cash (hashcash), The workload proof mechanism is used (proof of work). The prototype of this mechanism is used to solve the problem of Internet spam [ii]. Workload proof mechanism later became one of the core elements of bitcoin .

Harper and stonita (Haber and Stornetta) stay 1997 A protocol of using time stamp to ensure the security of digital files was proposed in [iii], This protocol becomes the prototype of bitcoin blockchain protocol .

Dai Wei (W Dai) He's a cryptography expert with a wide range of interests , He was in 1998 Invented in B-money,B-money Emphasize point-to-point transactions and unchangeable transactions . But in the B-money in , Each computer writes its own transaction record , It is easy to cause the system to be inconsistent with the account book . Dai Wei designed a complicated reward and punishment mechanism to prevent cheating , But it didn't solve the problem fundamentally . When Nakamoto invented bitcoin , I learned a lot from Dai Wei's design , And have a lot of email communication with Dai Wei .

Hal · Finney (Hal Finney) yes PGP One of the company's top developers , Also an early and important member of the code punk movement .2004 year , Fini has launched its own version of e-money , A reusable workload proof mechanism is used (RPOW). Hal · Fini was the recipient of the first bitcoin transfer , In the early days of bitcoin's development, there was a lot of interaction and communication with Nakamoto . Because of terminal illness , Hal · Finny has been 2014 Death in .

The birth of bitcoin

2008 year 9 month , Starting with the collapse of Lehman Brothers , The financial crisis broke out in the United States and spread all over the world . In response to the crisis , Governments take measures such as quantitative easing , Because of one's own fault 、 Big financial institutions in crisis . These measures raise a wide range of questions , And at one point triggered “ Occupy Wall Street ” motion .

2008 year 10 month 31 Afternoon, New York time 2 spot 10 branch , In a normal cryptography mailing list , Hundreds of members have received emails from people who call themselves Nakamoto ,“ I've been working on a new e-cash system , It's completely point-to-point , No need for any trusted third party ”, Then he leads them to a nine page white paper , It describes a new monetary system . Same year 11 month 16 Japan , Nakamoto released the first version of bitcoin code .

2009 year 1 month 3 Japan , Nakamoto dug up the first block of bitcoin on a small server in Helsinki, Finland —— Genesis block (Genesis Block), And got the first mine ” Reward ——50 Bitcoin . In the genesis block , Nakamoto wrote this sentence :

“The Times 03/Jan/2009 Chancellor on brink of second bailout for banks"

“ The chancellor is on the brink of a second bailout of the bank ”

This is the headline on the front page of the times that day . Nakamoto wrote it into the genesis block , It not only clearly shows the birth time of bitcoin , It's also a mockery of the old system .

Now , Bitcoin has become a leader in the field of digital currency , With a market value of billions of dollars , But Nakamoto is just 2010 He chose to retire in . Who is Nakamoto , For everyone who starts to understand bitcoin , All topics of interest . from 《 The New Yorker 》 To 《 Newsweek 》, The media have found several people who call themselves Nakamoto , Or someone considered to be Nakamoto . But without exception , These findings are all due to lack of credibility , It has been denied by readers and even Nakamoto himself . Who is Nakamoto ? Maybe we never know . Interestingly , The nickname 「 Silicon Valley iron man 」 Of Elon · Musk is also suspected to be Nakamoto himself , However, this argument has been denied by musk himself .

Bitcoin and blockchain

Bitcoin has gone through the controversy 7 More than a year's journey . In history, , There is rarely such a thing , People's attitude towards it is so clear , Supporters think it will change the world , Opponents think it's worthless . That means , It's easy to come to the latter conclusion .“ The coin ” Although this word accurately describes its financial attributes , But because of the image , Make most people understand how it can work with completely virtual “ The bit ” Connected and confused .

Actually , In the bitcoin system , The most important thing is not “ The coin ” The concept of , It's a place where there's no central storage “ Account book ” The concept of .“ The coin ” It's just the unit of account used in this account book . You can say that , Bitcoin is essentially a decentralized ledger based on the Internet , And blockchain is the name of this ledger . Here we can make an image analogy , If blockchain is a physical account book , A block is a page in the ledger , Information carried in blocks , It's the transaction content recorded on this page .

Blockchain is the core and infrastructure of bitcoin , It's a decentralized ledger system .

Since blockchain is a ledger , What's the difference between this account book and our traditional account book ? We know , The contents of the account book must be unique , This leads to the fact that bookkeeping is naturally centralized . In an age of underdeveloped means of communication , The same is true in today's information age . However , Centralized bookkeeping has some obvious weaknesses : Once something goes wrong with this center , If tampered with 、 Damaged , The whole system will face crisis and even collapse .

So here comes the question —— Can we build a decentralized and reliable accounting system that does not rely on any third party ? Decentralized bookkeeping can overcome the weakness of centralized bookkeeping , But it is not easy to realize such a system .

In the digital age , It's the computer that's in charge of accounting . here , We call every computer in the accounting system “ node ”. Decentralization means that there is no center , That is to say, every node participating in the system is the center . From the perspective of designing the ledger system , Each node needs to keep a complete account book . However , Due to the requirement of consistency , Each node cannot be bookkept at the same time . Because nodes are in different environments , The information received is naturally different , If you keep accounts at the same time , It will inevitably lead to the inconsistency of the account books , Cause confusion .

Since nodes cannot be bookkept at the same time , Then we have to choose which node has the power of accounting . however , If you specify that some special nodes have the power of accounting , It is bound to go against our original intention of decentralization .

It seems to be an impossible problem to solve .

Competitive accounting and incentives

The bitcoin blockchain designed by Nakamoto solves the consistency problem of decentralized accounting system through competitive accounting .

Mentioned earlier , A node can be understood as a computer in the access system , And the so-called competitive bookkeeping , It is based on the computing power of each node, that is “ Calculate the force ” To compete for bookkeeping rights . In bitcoin system , There's a power race about every ten minutes ( The amount of computing power will determine the probability of winning a round of competition , Nodes with high computing power are more likely to win the competition ), The winner of the competition , You get the right to book once , such , For a certain period of time , Only the winner of the competition can keep accounts and add new account information to other nodes .

that , In a decentralized system , Who has the right to judge the result of competition ? The bitcoin system works through a system called “ Proof of workload ”(proof of work, POW) It's done by our mechanism . A simple example , For example, we need to produce some toys , I'll give you some parts in the morning , Come back in the evening , See the toys you need on the table , Although I didn't watch you make toys from morning till night , And I'm sure you've done so much . This is the simple understanding of workload proof —— Through one ( Everyone can verify it ) Specific results can confirm ( Competitive ) Participants completed the corresponding workload .

Computing power competition costs , There is no incentive , Nodes have no incentive to compete . In Nakamoto's design , The node that wins each round of competition and completes bookkeeping , You will get a certain amount of bitcoin rewards from the system [vii]. And the reward process , It's also the process of issuing bitcoin . This design is quite ingenious —— It perfectly combines the incentive mechanism of competition with the issuance of money , While introducing competition , Solved the issue problem in the decentralized monetary system .

In this system , Each node only needs to act according to its own interests . Out of “ selfish ” The purpose of competition , Finally, it creates a huge computing power foundation to protect the security of the system . In such a delicate arrangement , Bitcoin is gaining more and more trust , And higher and higher values , And then it attracts more resources to invest in it , Become a positive circular economic system .

Because bitcoin is manufactured through the blockchain, it has created such a positive circular economic system , Only in the absence of a strong central organization to promote , Nature grows and grows .

Read here , Obviously we'll find , Although blockchain was born out of bitcoin , But blockchain, whether as a system or as a technology , Its application fields and development potential , It will be much more than money .