In the past year, it has been the craziest year of bitcoin. Bitcoin has surged from $1000 in the beginning of the year to $20 thousand. It suddenly attracted the attention of the whole world.
Thanks to the popularity of bitcoin, as the underlying technology, block chain has gradually become the current hot spot, and is considered to be the most disruptive technological innovation since the invention of the Internet.
1. What is block chain?
Block chain originates from bitcoin, which is essentially a distributed, decentralized database. It relies on the distributed algorithm of cryptography and mathematics. Without the need of third party intervention, the participants can reach consensus on the Internet which can not establish trust relationship, and solve the problem of reliable delivery of trust and value at very low cost.
We can use block analogy to describe block chain technology. Block chain technology is equivalent to a way of accounting for all people. All participants' accounts are exactly the same, and they are kept in their own hands (computers). Everyone has equal rights to participate in bookkeeping.
Every page on the account book is a "block", which is used to record transaction data. Each page will then be marked with page numbers and page numbers. By page numbering, each page can be linked as a chain, forming block chains.
Two, how does the block come into being?
Roughly every 10 minutes, there will be a new page. All participants can keep accounts on this page. Who can finish the accounts first, then you can add the page to the account book and get a reward (such as bitcoin). The pages of other unfinished participants will be cancelled, and they can only wait for another new page to be generated, and then restart the bookkeeping.
So the logic of the block chain is very simple, which is faster than who.
So, the new question is coming. What if someone does false accounts in the bookkeeping process? You know, in real life, fake accounts are also difficult to solve. How can people believe in this virtual account on the Internet that has no trust in each other?
In the absence of management, bitcoin has been running for ninth years since 2009, and so far no major problems have emerged, but the community is getting bigger and bigger.
And all this depends on the complex technical logic of the block chain.
Three, how to solve cheating?
1. transaction verification: transaction data uses user private key, and SHA256/ high strength irreversible encryption algorithm signature is used to ensure transaction data can not be tampered with.
Each page corresponds to a page number, and the page number has a complex coding system, rather than simple 1, 2, 3, 4... Through a series of encryption processing, the page numbers of each page are unique and prevent tampering. For example, when calculating the page number, there is a Nonce value, which records the number of SHA256 recorders. The Nonce value of the 100000th blocks is 274148111, that is, 274 million times is calculated before a valid page number can be obtained, and the page can be added to the account book.
2. block verification: Forged blocks, then all the data of the block will be re forged data. The amount of computation is too large to be feasible at all.
As mentioned before, every page of the account contains not only the page number of the page, but also the page number of the previous page. If the content of the current page changes, or the page number of the previous block changes, the page number of the current page will change.
If someone modifies a page account, the page number changes. In order for the subsequent page to be connected to it, the person must modify all the pages at the same time, otherwise the page that has been changed will be separated from the account book. Because the computation of encryption algorithm is time-consuming, it is almost impossible to modify multiple pages at the same time.
It is through this linkage mechanism that the block chain guarantees its reliability, and once the data is written, it can not be tampered with. This is just like history. What happened is what happened.
3. distributed storage: any participant has an independent account and is authorized by more than 51% users of the entire network.
The account books of all participants are exactly the same. They are kept in their own hands and updated at any time. If someone tampered with the content of a page, the person must also modify more than 51% of the participants' account books. It is almost impossible to change so many books at the same time.
4. chain validity: the longest chain of all participants as a valid chain can completely prevent illegal chain forgery.
As we said before, who will remember the bill quickly and whose page will be added to the account book. But, if there are two people who will complete the bookkeeping at the same time? Two pages of content have been added to the account book. How do we make two books?
The agreement stipulates that after the two accounts are formed, the first 6 pages of the account books will be identified as official accounts and other accounts will be abandoned. The hidden logic is that if most people (computing power) choose to trust a certain account book, then it should be true.
To sum up, the two accounts are not likely to happen at the same time. This also shows a price of the block chain, that is, transactions cannot be confirmed in real time and must wait for at least one hour.
Four, the application scenario of block chain?
The biggest significance of block chain is that it can turn many trust problems of high human cost into machine consensus. However, in order to ensure the reliability of the data, the block chain also has its own cost. First, efficiency, data write to block chain, at least wait for ten minutes, all nodes synchronize data, it takes more time; two, energy consumption, the generation of blocks requires miners to make countless meaningless calculations, which is very energy consuming.
Therefore, the application scenario of block chain is still limited at present. It needs to meet the following situations:
There is no management authority that all members trust.
Data written is not required for real-time use.
The benefits of mining can make up for its own cost.
If the above conditions can not be satisfied, the traditional database is a better solution.
At the moment, the chain is hot. It is not the technology to solve the real problem, but the hot money in the fund-raising, speculation and valuation, not related to technological innovation. Therefore, regulators have adopted a series of actions such as banning ICO and closing the digital money exchange. However, a sweeping attack can not solve the problem fundamentally. If the times choose block chains, if China's block chain technology continues to stagnate, it may not be far away from the industry.
For the current block chain fever, the regulatory authorities should take the initiative to intervene, distinguish between technological innovation or fund-raising speculation, and comprehensively curb the fund-raising speculation under the name of the block chain. At the same time, we should also introduce block chain technology and industrial development support policies in line with the development of China's block chain technology and application, focusing on supporting key technology tackling, major demonstration projects, "double innovation" platform construction, system solution research and development, and public service platform construction. At the same time, domestic key enterprises, research institutes, universities and user units suggest strengthening joint efforts to speed up the key technologies such as consensus mechanism, programmable contracts, distributed storage, digital signature and other key technologies.
For example, in February 4th this year, Hangzhou's "two sessions", Hangzhou first wrote the "block chain" in the government work report, to speed up the development of block chain and other future industries. Hangzhou has been ahead of the country in the block chain. As the surging commentary said, "only by embracing the chain of blocks can we truly manage the market". We should embrace the technology of block chain and face it rationally and objectively, and give relatively relaxed development space, perhaps the best policy way at present. Judging from the recent trend of public opinion, I think it is not far away from the real policy.
Wu Zhongwang, the vice president of chain science and Technology Research Institute of Zhejiang Zhijiang block, and CTO, a senior software engineer of Hengsheng Electronic Products Certification Department, deputy general manager of the Yada wind control division, has more than 15 years of experience in technology and product development in banking, securities, payment, Internet Finance and other fields, and the early researchers of block chain technology have specialized research and opinions on the application of block chain technology in finance and other scenes.