Topic selection of blockchain

1.

"blockchain is equivalent to this account book, and the block is equivalent to a page of this account book. The information carried in the block is the transaction content recorded on this page. The blockchain is block by block, and each block is filled with transaction records and connected together to form a chain, which is called blockchain. "

take bitcoin as an example, there is a "power race" every ten minutes to compete for the right to charge. It's like saying that you have a lot of calculation power, just like your muscles are stronger and more capable of fighting. Everyone will convince you to keep this account, that is, the right to write a block (note that it is not the content in the block) to the general ledger of the blockchain. However, it should be noted that computing power can only determine the probability of winning the competition. For example, there are several lotteries in total, and those with more computing power can buy more to improve the winning probability. However, those who buy more may not win the lottery in the end.

blockchain is a data block chain guaranteed by such computing power. Starting from the first block, each block collects data according to certain rules, and then attaches a value to these data, so that the result of the formed data block after similar one-way function calculation falls into a certain range. By estimating the computing power of the whole network and the size of the control result range, the data blocks that meet the requirements can be found in a long enough time. This calculation result will be included by the next block, and the chain data structure formed in this way is called blockchain

each small ledger is called a block, and each different blockchain protocol (generating different cryptocurrency) will specify the size of each block (the initial bitcoin is 1m). The ledger constitutes a block, the block constitutes a chain list, and the block header contains the hash value of the previous block, which is the blockchain. In this way, no one can modify the content or exchange the order at will. If you do, it means you need to recalculate all the special numbers

regulations allow everyone in the world to build blocks. Every person who builds a new block (finds this special number - sha256 value has 30 zeros) can get a reward. For this part of people (miners) who build a new block:

1. There is no sender information, There is no need to sign

2. Each new block will add a new virtual (encrypted) currency to the whole currency

3. The process of building a new block is also called "mining": it requires a lot of work and can inject new currency into the whole economy

4. The work of mining is: receiving transaction information, building blocks, broadcasting blocks, Then get new money as a reward

for each miner, each block is like a small lottery, and everyone is trying to guess the number quickly until a lucky person finds a special number, so that there are many zeros at the beginning of the hash value of the whole block, and they can get a reward. I remember a Zhihu respondent gave an image analogy. Blockchain is like a king with a beautiful daughter (block). Many young people are looking forward to it. The king's method is to give a very difficult topic for all young people to calculate (learning to change their lives), Who can calculate quickly (or be lucky in the process of calculating the hash value) will be able to win the beauty

for users who want to use this system to collect and pay, they don't need to listen to all the transactions, but just listen to the blocks broadcast by the miners, and then update them to their saved blockchain

"block" can also be imagined as a box, There are some digital currencies and a small note in the block, on which the only transaction information generated in the past ten minutes is recorded, such as "small a transferred to small B100 yuan"; Of course, this piece of information must have been encrypted to ensure that only small a and small B (through the key in their hands) have the ability to interpret the real content

after this magical block was created, it was soon buried underground. Where is it buried? No one does not know that all computer nodes need to participate in digging three feet before it is possible to find (find an effective workload proof). Obviously, this is an event with huge workload and random results. However, for the computer node, once the block is g out from the ground, it will get the valuable digital currency in the block, as well as the tip paid by small a in the process of "small a transferred to small B100 yuan". At the same time, for this node, only he has the right to truly record the contents of the note, which is an honor, while other nodes can only use its , a without digital currency blessing. Of course, there are some other special things about this magical block.

the process of computer nodes digging out blocks from underground is called "mining". As I said just now, this is a huge workload, a lot of luck and a lot of profits. A node on zhangheng road in Pudong New Area of Shanghai, China, suddenly jumped out and said excitedly, "I've g the block! The little notes inside are all valid! The reward belongs to me! ". Although Zhang Heng Road node has got digital currency at the moment, for other computer nodes, because it also involves some other interests, they will not choose to believe what Zhang Heng Road node says by default; Based on the principle that strangers do not trust each other, they take the so-called block () g by Zhang Heng Road node, and start to check whether the small note information in the block is true and effective, etc. In the world of blockchain, nodes check the accuracy of the small note information, or indirectly or directly judge whether the node that successfully digs out the block is lying How to define the true and effective information of a small note will be explained later, but I won't go into details here. In the verification process, each node will directly express their identification (accurate) and attitude towards zhangheng road node through the following two behaviors: stop half or even 80% of the mining process; Add the block () g out by zhangheng road node to the end of its own blockchain. You can be a little confused: if you stop mining, you may have done 80% of the mining work. Then 80% of the previous work is in vain?! Then, what the hell is at the end of the blockchain? For the first puzzle. I want to say that what you said is right, but there is no way. The reality is so cruel. Even if 80% of the work is done, you have to give up. The 80% of the work can be regarded as useless, absolutely damaging the wealth and the masses. The second puzzle is, what is the ghost at the end of blockchain and blockchain? Here, it is not clear in advance, but you can simply imagine: blocks are generated and g out periodically, and a computer node may have executed "take blocks from others" n times in advance; The process of "checking the validity of small notes" must have stored n blocks on its own node, and these blocks will be arranged in a chain in order of time. Yes, this chain is what you always think of as the blockchain. If you still can't understand, it doesn't matter. There will be many opportunities for in-depth study later in the article

go into the more microcosmic world of the block and have a look at what the little note really is, how it came into being and its mission all its life: when initiating a transaction, the initiator will receive a little note, and he needs to write the transaction record, such as "stealing transfer to a piece of RMB 340" on the paper. It's amazing that when it's finished, on the back of the note, the transaction record will be automatically formatted to at least contain the two important fields of "input value" and "output value"“ Input value is used to record the effective source of digital currency, and output value is used to record the object to which digital currency is sent. The newly created note is immediately marked as an "unconfirmed" note. Small pieces of paper that are successfully g out of the ground and eventually connected to the blockchain are initially marked as "valid.". If the valid slip is used as the input value of other transactions, the valid slip will soon be marked as invalid. Due to various reasons, the block is disconnected and discarded from the chain, and the small notes once marked as "valid" in the block will be re marked as "unconfirmed". There is no concept of account balance in the blockchain. The digital asset you really own is actually a piece of transaction information; Get the balance in your digital wallet by simple addition and subtraction. The above 1, 2 and 3 are just the knowledge points forced to you at the beginning. Some of the descriptions may be a bit confusing, which makes you feel confused. Only by understanding the whole blockchain can you have a more comprehensive understanding of the mystery

block capacity. Bitcoin specifies that the block capacity is 1m when it is created, or in the source code. The reason why it was originally designed as 1m is, on the one hand, to prevent DoS attacks. On the other hand, when Zhongben Cong created the blockchain, the capacity was 32m. However, he changed the block capacity to 1m through a humble commit like "clear up". In order to prevent the volume of the blockchain from growing too fast, he added some mystery to the problem of block capacity. The capacity of 1m means that the maximum number of transactions processed by bitcoin is about 2400 (the size of 486882 block 1034.39 is very close)

to put it bluntly, blockchain is a small book for distributed bookkeeping, a tool for bookkeeping, and based on cryptography and cryptography technology, once data transactions are recorded in the book of blockchain, data can not be tampered with and denied. The Internet is the transmission of value, and the blockchain is the transmission of trust. Under the premise of blockchain technology as a credit endorsement, each node in the blockchain changes from a single center to a unified multi center with multi-party participation, which can achieve transaction transmission without the participation of a third party organization and improve the efficiency

2. Do you want to learn blockchain development technology or just want to know what blockchain is? If it is the former, you can look at the code of other blockchain projects and learn about it first. If it is the latter, we can pay attention to some good blockchain we media. Blockchain is an emerging instry. There is no ready-made training course. It depends on self exploration and understanding.

3. Is this the college entrance examination?

4.

On August 6, 2018, Mr. Cai Yi, financial instry consultant of Huawei Company and founder and CEO of Huaxuan technology, was in daga | blockchain & amp; AI (core group) made a special topic sharing, the theme is: the current situation and Prospect of blockchain finance. The following text is arranged according to the speech of the lecture and has been reviewed by the author

Cai Yi: Consultant of financial instry of Huawei, founder and CEO of Huaxuan science and technology, founder of shared reading association, member of China Writers Association, engaged in financial science and technology research for more than ten years, and is a senior expert in digital transformation of banks

good evening, everyone. I'm very glad and honored to share some thoughts with you here

let's make a simple self introction: my name is Cai Yi. I worked as a writer in my youth. I wrote some books, magazines and novels in the 1990s. At that time, there was no Internet. After work, I have been engaged in the information work of financial instry, from financial channels to data centers, from outlets to technology, witnessed the development of financial technology, and also found some problems. After 2014, I worked as an investment partner and in recent years as a financial instry consultant in Huawei. From the cognitive level, I worked as a consultant for the talent development of digital transformation in the financial instry

in 2015, I started Huaxuan technology and sharing reading club. At present, we mainly focus on the cognition of blockchain and the implementation of financial technology solutions. At the cognitive level, interactive sharing and knowledge management are carried out in the way of book club. At the technical level, the process and scene of the financial instry are reshaped by combining blockchain, big data and AI technologies. I am interested in blockchain and often study and discuss with some friends. Of course, some views are still superficial. I hope you can exchange more criticisms and corrections

the elite think tanks in the United States once believed that the core of maintaining global leadership is science and technology, which must rely on economy, and the core of economy is finance. So what is the future of finance

today's topic is: the current situation and Prospect of blockchain finance. I would like to introce it mainly from three aspects:

< UL >

briefly introce finance and financial system

the current situation of blockchain finance

prospect of blockchain finance

First of all, let's talk about the concept of finance. The word "finance" originated from Japan after the Meiji Restoration (1868), which is somewhat related to the gold standard established by Japan in 1897. At the beginning of the 20th century, it was introced into China from Japan. It was first proposed by Finance Minister Liang Qichao in 1902. At that time, Zhang Zhidong raised his objection. Therefore, after the Sino Japanese War of 1894, China remained in the silver standard, but it also made China avoid the Great Depression of 1929

The original meaning of finance is "money accommodation", which refers to the circulation of funds in the society. Later, its meaning has been expanded to indicate transactions and economic activities related to money and credit. In fact, there is another reason: gold used to be the only medium in international trade, and its value and wealth were based on gold. Therefore, when making standard gold bars, people need to melt gold into shape, which may be the original meaning of the word "finance", that is, to melt metal

Finance is the general name of currency circulation and credit activities and the economic activities associated with them.

let's look at the definition of Finance later: finance is the general name of currency circulation and credit activities and the economic activities associated with them. In a broad sense, finance generally refers to all the economic activities related to the issuance, custody, exchange, settlement and financing of credit currency, Even including the trading of gold and silver, the narrow sense of Finance specifically refers to the credit currency financing

In short, the contents of finance can be summarized as the issuance and withdrawal of money, the absorption and payment of deposits, the issuance and recovery of loans, the trading of gold, silver and foreign exchange, the issuance and transfer of securities, insurance, trust, domestic and international currency settlement, etc. To put it more bluntly, finance has two-way feedback. The institutions engaged in financial activities mainly include banking, insurance, securities, trust, financial leasing, etc. We all know this better and have frequent contact with it. Therefore, to understand the meaning and institutions of finance, we also need to understand China's financial system

2 China's financial system the development of China's financial system can be roughly divided into five stages:

initial formation stage, the first five years (1948-1953): the establishment of the people's Bank of China (1948). At this time, the PBC is far from what we want now. But it marks the beginning of new China's financial institution system

In the second five years (1953-1978), the people's Bank of China (PBC) is the only financial institution in China that deals with all kinds of banking business, integrating the central bank and ordinary banks. In fact, reunification means that we the model of foreign countries. I will not talk about specific countries

In the third five years (1979-1983), the Bank of China (established in 1912), the Agricultural Bank of China (established in 1951) and the Construction Bank of China (established in 1954) were restored or established one after another, but the people's Bank of China still integrates currency issuance and credit. We can see that after the reform and opening up, China's financial instry has developed very fast

the diversified financial institution system has begun to take shape. Ten years (from September 1983 to 1993): it has formed a financial institution system with the people's Bank of China as the core, the four major professional banks of instry, agriculture, China and construction as the main body, and other financial institutions coexisting and cooperating. After 1987, there were Bank of communications, China Merchants Bank, Shenzhen Development Bank, CITIC and Hengfeng. In 1988, Ping'an, Guangfa and Xingye appeared. Everbright, Huaxia and Shanghai Pudong Development Co., Ltd. appeared in 1992, and the Securities Regulatory Commission was set up in the same year

the stage of building and improving the social * * market financial institution system (since 1994): it has formed a relatively complete financial institution system with "one bank, three meetings" as the leading role, large, medium and small commercial banks as the main body, and a variety of non bank financial institutions as the auxiliary wing. In 1994, three major policy banks (China Development Bank, Export Import Bank of China and Agricultural Development Bank of China) were established. In 1995, Minsheng Bank, the first private commercial bank, was established (which is of great significance). In 1998, urban commercial banks emerged and CIRC was established. In fact, the CBRC appeared relatively late, and it was only established in 2003. Since then, the pattern of "one party, three meetings" has been formed. However, not long ago, the China Banking Regulatory Commission and the China Insurance Regulatory Commission merged into the China Banking and Insurance Regulatory Commission. You can pay attention to this

from the perspective of evolution, the normative research of finance is often linear

that is, we often take a certain evolution form as the standard (usually developed market economy system, such as the Soviet Union, Germany, the United States and even Japan), describe the progress path of the financial system from non marketization to marketization, from inefficient allocation of financial resources to efficient allocation, and focus on explaining the gap of the standard form and the reasons

In fact, we can find from the development process of China's financial system just now: since 1978, China's financial system has evolved in the direction of marketization, standardization, diversification and internationalization, All kinds of financial institutions show a "network" and "strong connection" business form, that is, the connection degree between banks, banks and other financial institutions, as well as financial sub markets has increased significantly, and the credit connection is increasingly close, mixed and complicated

the ecological environment of financial instry has also undergone some obvious changes. On the one hand, traditional formal financial institutions seek to speed up transformation and innovation, and strive to seize the opportunity in business strategy, market positioning, management structure, format and proct innovation. On the other hand, a large number of emerging financial institutions have emerged

financial format also presents new characteristics such as real estate financialization, non bank institutions "banking" and asset securitization

The above changes are beyond the imagination of the instry, regulators and policy makers, and will bring a series of impacts:

on the positive side, the scale and composition of the financial system have been expanded, the business expansion and financial service capacity of financial institutions have been improved, the financial market has been developed, and innovative payment has developed rapidly. That's what we're going to talk about in financial technology

in a common saying, when the forest is big, there are all kinds of birds. The negative aspects are mainly reflected in the following aspects: the interaction between the

financial system and the real economy tends to be complex, and the role of the financial system in promoting and amplifying asset bubbles is underestimated. p>

the reticulation and strong correlation of the financial system widen the gap between the financial instry and financial supervision, and weaken the effectiveness of traditional supervision. China's current financial supervision system has only been in operation for more than ten years

the transmission path and mechanism of monetary policy through the financial system have changed (the transmission chain of monetary policy has been lengthened or deformed, the conctivity and effectiveness have declined), and the initiative and effectiveness of regulation are facing new constraints. Since its establishment in 1996, the current monetary policy framework has been constantly improved in response to the development of economy and financial market, but the complexity of the financial system in recent years has put it to a new test. Broad money M2 is also impacted by financial deepening, electronic payment and other factors, and further weakened by the shadow banking system

all kinds of cross market, cross business and cross-border behaviors to evade supervision make a variety of risk factors intertwined, such as: capital pool operation with serious mismatch of maturity and procts hides large liquidity risk, proct nesting leads to risk transmission, insufficient shadow banking supervision, local debt, real estate, external shocks, etc., all of which bring great challenges to the stability of the financial system

without comparison, there is no harm, and China's financial system as a whole is relatively backward. This kind of backwardness is mainly reflected in the backwardness of bank innovation: the people's Bank of China announced in October 2015 to abolish the "interest margin protection", while the interest rate of the United States had been completely marketized as early as April 1986, and China was nearly 30 years late

3 the institutional framework and basic problems of China's financial system

Second, the * * third party acts as a credit intermediary to guarantee the realization of asset transfer transactions

the third is the transaction settlement and clearing completed by the centralized clearing organization

Based on this, there are also four problems:

1) credit system and trust mechanism. Traditional finance must have strict transaction records to accumulate credit. Without transaction records, it is difficult to achieve financing or loans, because there is no technical means to ensure the safety of transactions between the two sides

(2) transaction settlement takes a long time. The time of traditional financial transactions has been speeding up, but the settlement time is still relatively long, especially for cross-border transactions, which often can not arrive immediately

(3) the cost of intermediary service is high. The traditional financial transaction system is very important

5. You can download a "coin listening" app, a live answer software. They will share 12 questions every day, and the questions in it are knowledge related to blockchain. A must for beginners! I'm also learning. Let's refuel together~

6.

Real estate name: Zhuzhou Tianyue Ming

City: Zhuzhou

real estate location: the intersection of Tianyuan road and Guihua No.4 road

developer: Zhuzhou Deyuan Real Estate Co., Ltd.

ownership period: 70 years

building type: slab building, small high rise,

bus route: Huaqiang Road West (bus stop): T63 road; Yuntian Road South (bus stop): T63 road; Youma (bus station): T63 road; Yuntian East (bus station): No.106; T6 road; Yanzitang (bus station): No.106; T6 road; Yuntian town government (greeting station) (bus stop): No.106; Yuntian town government (bus station): No.106; T6 road; Acid pond (bus station): 106 road; T6 road; Jinyuan Hotel (bus stop): No.106; T6 road; Fulin (bus station): No.106; T6 road

other modes of transportation: public transport, urban rail

Planning Information: it covers an area of 65403 square meters, plot ratio, greening rate of 30%, a total of 10 buildings, parking space of 374

surrounding facilities: Fangte tourist resort, European town, Yunlong water park, Aoyue ice and snow world, Yunlong Holiday Plaza, Yuntian Middle School of Zhuzhou No.2 Middle School, Yunfeng Lake Forest Park Outlets square, Yunlong hospital, Dafeng station of city railway

internal supporting: 2000 square meters commercial street

Real Estate picture:

(the information is for reference only, and the final information is subject to the information of the sales office.)

Click to view more comprehensive, more timely and more accurate new house information