区块链金融题目,区块链技术金融应用实践

❶ The technical characteristics of blockchain include: ( ). a Decentralization b Traceability c Openness and transparency d Non-tampering

The technical characteristics of blockchain include decentralization, non-tampering, consensus trust mechanism, openness, anonymity, cross-platform, etc.

6. Cross-platform

Similar to the TCP/IP protocol of the Internet, blockchain can also be regarded as a basic communication protocol. The cooperation of other mechanisms together constitutes the value Internet based on blockchain. Nodes on the blockchain network operate independently based on common algorithms and data structures. They mainly consume computing resources and have nothing to do with the platform. Computing nodes can be deployed on any platform.

It can be said that the characteristics and development of blockchain come from the soil where it was born - the development of Internet technology and the rise of cloud computing and big data.

❷ What is blockchain

In the simplest terms, blockchain is a distributed Ledger.

To understand what this means, we first have to look at its opposite: a centralized ledger. Because blockchain technology started with finance, we will also introduce it below using banks as an example.

The following is our process for using bank debit card transactions:

You can swipe your card to purchase goods in stores.

The merchant sends a statement to your bank for the agreed upon amount.

Your bank will verify that you may have authorized the purchase.

The bank sends the money to the merchant.

Finally, the bank records this information in its ledger.

There’s a lot of technology involved here, but that’s basically it. The last step is important - the bank records all transactions made by the customer. This ledger goes all the way back to the first transaction the bank made.

This ledger is kept, maintained and regulated by the bank. You can read it in your online bank account, but you can't change it. The bank has complete control. If it decides to make a change, there's nothing you can do about it.

Crucially, if hackers were able to access a bank’s ledger, that could cause a lot of problems. They can change the account balance to make it look like certain transactions never occurred, etc.

This is why distributed ledgers are so cool.

Blockchain Network Visualization

If a bank operates on a distributed ledger, each member of the bank will have a copy of the ledger, and whenever any member of the bank When they make a purchase, they tell every other member of the bank.

Each member will verify the transaction and add it to the ledger (the added record is called a "block""). This has some important benefits, as there is no centralized authority that can manipulate the records. Hackers gaining access to one ledger will not be a big problem because other ledgers can easily verify it.

Another aspects, it requires a lot of work. In short, the second system is blockchain (at least in financial scenarios).

As mentioned above, blockchain is a decentralized list of transactions .If I send Xiao Ming 2 Bitcoins, I will send a message to everyone in the network saying "I am sending Xiao Ming 2 Bitcoins" and they will all record the transaction.

Blockchain How will it change our lives in the future?

One thing is important about blockchain, it is a public resource, no one really owns it because everyone owns it.

Blockchain is not just science fiction. We don’t need to understand the mechanics behind this technology, but you do need to understand that it may revolutionize our lives in the next 20 years.

This sounds bold, but remember, 20 years ago we were browsing the Internet on Netscape, using state-of-the-art Motorola flip phones, and buying our first DVD players. At that time, if we imagined that computers could Holding it in your hand, you can buy a car, make payments, and watch movies on it, which will definitely be considered a fantasy.

Although the impact of blockchain may not be as obvious as that of the Internet, it is not as obvious as the Internet. Mobile phones are so tangible, but blockchain will effectively solve many troubles in daily life. For example, intermediaries cheat people, transaction delays, etc. In our current lives, middlemen can be seen everywhere, and we take them for granted as a part of life. If One day, these intermediaries will no longer exist, and you will find that the world will become a different place.

Imagine that by 2040, blockchain may become a mature and widely used technology. technology. When one day, you can't live without the blockchain just like you can't live without the Internet now, you will be surprised to find that this decentralized accounting technology has simplified the complexity and become a part of your lifestyle< /p>

❸ Explain blockchain in vernacular

img src=' https://p26 . toutiaoimg.com/large/39b 70000088 e 51 B3 c 258 '/

Recently, various ICO financial scams have been blocked in China, but this does not hinder the vigorous development of blockchain technology. In the end, technology is innocent and can bring benefits to people. As for how to use it, it depends on people Let’s go and do it. If the operation is good, you can recommend development. If the operation is not good, just like the major ICO projects. Find some knowledge for Internet celebrities to conduct so-called illegal fund-raising and financial fraud.

After talking for a long time, what is the blockchain? ?Speaking of blockchain, the first thing that many people think of is Bitcoin. We needTo solve a problem. Bitcoin is a blockchain, but blockchain is not Bitcoin. Simply put, blockchain is distributed ledger technology (DLT), not a token. It has many characteristics, such as decentralization, traceability, and difficulty in tampering.

(1) Blockchain is a distributed database

First of all, this is a decentralized distributed architecture system. Therefore, having only one central server or node is not called a blockchain. For example, if you go to Taobao to buy a mobile phone, you and the seller are strangers and have no basis for trust. If you give the money to the seller first, the seller may block you by not delivering the goods, and then your mobile phone money will be gone. If the seller ships first, do you pay? It is possible that you do not pay the seller after receiving the goods, and one party may lose money anyway. At this time, a third-party guarantee is needed to solve the trust problem. Just like Alipay now, you give money to Alipay and the seller will deliver the goods. When you receive the goods, the seller will receive the money.

The above example is a centralized system because all guarantee work is handled by Bora, a third-party payment company. Suppose one day Alipay wants to tamper with data, neither buyers nor sellers can do anything because all authority is in the hands of one company.

At this time, a distributed database is needed. This third party is no longer Alipay, but thousands of monitors. When you buy a mobile phone on Taobao, you will shout to everyone that I am going to XXX to buy a mobile phone, and I paid XXX yuan. The other person will yell like everyone else. I collected XXX’s mobile phone bill and sent it over. In this way, everyone knows about this transaction and everyone is recording this transaction, so it is useless if one or two nodes have problems or malicious behavior, because most nodes have recorded this matter.

(B) Blockchain uses encryption technology to ensure data security

There are two important points here: 1. Crypto-enabled hash function 2. Asymmetric encryption.

If you are interested in specific concepts, you can go online, but people without basic knowledge may not be able to understand it, because these two points are too professional. In fact, if you only know the use of blockchain, you don’t need to have an in-depth understanding of it. It is also a technical concept. All you need to know is that blockchain relies on these technical points to ensure data security and is not easily tampered with. Of course, many people say that these two points can guarantee 100% non-tampering. I want to be a little conservative here. As an author who works in the security industry, I have always been skeptical about 100% security, so it may be more appropriate to call it difficult to be tampered with.

I will briefly introduce these two concepts and try to explain them clearly in plain English.

1. Cryptographic Hash Function

This is mainly used to verify the integrity of information. For example, I sent a message to the company leader saying that I was sick on Friday and needed to take a day off. At this time, a hash value will be generated based on the message I sent, such as: 123456. At this point, when the leader receives this message, a hash value is also generated. Because the content of the message I sent has not changed (it has not been tampered with), the hash value remains unchanged, still: 123456. This is if someone wants to tamper withChange this message and get sick on Friday and need to take a year off. At this time, the hash value will change, such as: 123489. That's when we learned our information had been tampered with.

2. Asymmetric encryption

It is mainly used for information encryption and authentication. It is actually two keys, one is called the public key and the other is called the private key. Public key encryption, private key decryption.

A public key is a key that everyone has. You own it, I own it. We can all encrypt with this key, but when decrypting it must be decrypted with my private key. If you don't have my private key, you can't decrypt it.

(C) The blockchain uses a consensus algorithm to reach consensus on new data.

The role of the consensus algorithm is to enable all nodes to reach a consensus on the new block. In other words, everyone must approve the new block.

For a centralized deployment system, this is simple, everything is controlled by the center, but in the distributed system of the blockchain, it is very complicated. For example, there are three nodes. A said he bought a mobile phone from XXX store and paid for it, B said he didn’t pay, and C said he didn’t pay enough. Then who do you listen to? What's more, blockchain technology is not as simple as three nodes, but a huge distributed system.

This is when a solution is needed. There is a corresponding problem in computer science called the "Byzantine Universal Problem" or "Byzantine Fault Tolerance" (BFT). This question was raised not because of Bitcoin, but because of a special background.

Early aircraft had three independent control systems. Why do we need three independent control systems? For example, in an emergency, there is a plane opposite. How to judge whether you should hide? If there is only one system, there is no choice, which is equivalent to centralized deployment. If the system breaks, you're dead. What if one of the two systems breaks? The good ones are said to hide, and the bad ones are said not to hide. The computer cannot judge the final result. Therefore, three independent systems are needed to support it, and the probability of two total failures is still very small. But this only takes into account injuries. What should I do if there is a malicious system? Is three enough? The answer is no, we need four systems to maintain consensus.

The use of blockchain is similar, because it is supported by a huge number of nodes, and each node is an independent system without interfering with each other. We can assume that the number of failed nodes and malicious nodes is limited, so it will not cause abnormal consistency of data.

Related Q&A: What is blockchain? What is the use?

Blockchain is a new computing paradigm and distributed infrastructure that uses fast chain data structures, distributed node consensus algorithms, cryptography and smart contracts based on automated script code to produce, verify, store and transmit data. It can also be said that blockchain is a distributed ledger technology that can provide a decentralized trust mechanism in a non-trust environment, allowing multi-party participants to conduct secure and trust-based transactions without intermediaries.

The core advantage of blockchain technology is decentralization. It can realize decentralized credit-based transactions in a distributed system where nodes do not need to trust each other by using data encryption, timestamps, distributed consensus and economic incentives. Peer-to-peer transactions, coordination and collaboration, thereby providing a solution to the common problems of high cost, low efficiency and insecure data storage in centralized institutions.

The fields of use of blockchain include digital currency, certificates, finance, anti-counterfeiting and traceability, privacy protection, supply chain, entertainment, etc. With the popularity of blockchain and Bitcoin, many related top domain names have been registered. It has had a relatively large impact on the domain name industry.

Related Q&A: Can you explain to me what a blockchain is in an easy-to-understand way?

Er Gazi is my friend since we were young, and we were naked in Hegou together. Later, I came to the city to study and work, and lived a life as a drifter in the north; he farmed at home and also did some small business, and now he has a son and a daughter, and his life is safe. He envied my so-called "seen the world", and I envied his simple life without the pressure of mortgage loans. We have completely different and mutually enviable lives??

That day, Ga Zi came to me on WeChat and asked "District" What is a blockchain?" I was stunned for a moment, how could this idiot care about such an avant-garde word? I pretended to be calm and prepared to talk about the technical principles bit by bit, but I could see the confused expression of that idiot through the screen of my mobile phone. How to explain "what is blockchain" to people who have a little bit of Internet concepts and technical foundation? This seems to be a very thorny problem??

The village commissary interprets the core of blockchain (picture quoted from the Internet)

The core essence of blockchain is "decentralization", and almost all operating modes of blockchain operate around the concept of "decentralization". Once you understand what "decentralization" is, you can basically explain the question "what is a blockchain?" For Erga, of course, he must perform a version that he can understand.

“I said, Gazi, are you still open that canteen at the east end of the village?” Gazi answered yes. I decided to use this canteen as an example to explain the actual use of blockchain in modern business and financial models. Scenario, so that he can better understand what blockchain is.

"Are there still many villagers who take credit now? By the end of the year, some of the accounts cannot be remembered clearly, and there are still many defaulters or those who refuse to accept their accounts?" At this point, Ergazi got emotional and kept complaining. Nowadays, people's hearts are not as old as before, and business is difficult to do!

"In the past, the operation model of your canteen was a typical centralized one. You granted credit to the villagers and allowed them to take accounts on credit. All accounting was done directly through you and our villagers. You were the center of all accounting affairs." Ergazi said I understand, let me continue.

I said: "If you fail one day, then all the accounts will become dead accounts? It will be difficult to get back the IOUs written in black and white, let alone those who remember the accounts verbally, but the block The decentralization of the chain can solve this problem very well. As long as the earth still exists, the blockchain will remember that every account will exist forever." Erga became more energetic after hearing this.

The essence of blockchain is "decentralization"

"The essence of blockchain is decentralization. Once someone takes credit from you, all the neighbors in the village will help you keep accounts. Because of the accounting There are many nodes, it is neither easy to make mistakes nor others can refuse to pay, so everyoneReach a consensus. If someone maliciously fails to repay the debt, the whole village will know his character, and no one will be willing to have financial dealings with him in the future??"

At this point, Gazi was obviously a little excited. It seemed that he was I was really worried about the credit issue. Seeing that Gazi was interested, I also felt a small sense of accomplishment and continued: "Of course, the above is just an analogy. In fact, the blockchain does not really allow villagers to get paper. The pen helps you keep accounts, but it is done through the Internet and computer networking. "

At this time, Gazi was a little confused and asked: "Then what others bought from me, wouldn't everyone in the village know it? Then who would buy things from me? There is really no privacy at all. And you don’t have time to keep accounts here. Last year’s accounts are said to be this year’s. What if you keep procrastinating? "

"Okay, Gazi, your question is on point. "It seems that Gazi is not stupid at all, and he is very shrewd in doing business. I continued to explain: "So, the recording and transmission of this information are all done through encryption. What you see is a picture of numbers and English. String, and each account has a timestamp to record the time of occurrence, which cannot be relied on. "

Gazi had another question: "Is it possible that the people who owe the debt have a good relationship with the villagers, and they join forces to tamper with the accounting? Then you won’t be able to explain clearly at that time??”

“Gazi, that’s all you have, haha. "I understood Gazi's concerns and continued to explain: "The mechanism of the blockchain requires more than 51% of people to agree to tamper with a bill. Everyone has a degree of closeness and distance between them, and it is impossible for everyone to favor the same person. If it were a computer, more than half of the computers on the entire network would need to recalculate. This project would be so huge that it would be almost impossible to complete??"

In this way, through the actual situation of the canteen and combined with some scenes in life, Gazi understood What is in the blockchain: decentralization, distributed accounting, consensus mechanism, encryption mechanism, timestamps, and the characteristics of being difficult to tamper with.

Ergazi was silent for a moment, seeming to be digesting the example I just gave him. I don’t know how much he can understand the example. Not long after, he sent me a voice message on WeChat: “What does blockchain mean? In the past, when I bought goods online and paid, I had to go through Jack Ma’s house. If there is a blockchain, can we directly trade with the seller? Anyway, the accounting is very safe. "

"Okay, Gazi, it's really clear at first glance. Blockchain is essentially a decentralized distributed ledger data cloud. Of course, it can be understood according to your understanding. "I'm very happy that Gazi can roughly appreciate the true charm of the blockchain. Fortunately, my words have not been in vain.

What is Bitcoin? (Picture quoted from the Internet)

"Then Bitcoin What is this thing again? What does it have to do with blockchain? "Gazi asked.

I thought about it briefly and decided to continue to explain to Gazi with the story of the canteen: "Your canteen, the villagers can't keep accounts for you for free all day long, right? Do you have to carry some during the holidays? Things like cross-fertilization, this is the reward mechanism of the blockchain, everyone who participatesAnyone who keeps accounts may receive a reward. "

"Then what are the rewards based on? There has to be a rule, right? "Gazi asked very puzzled.

I explained: "Zhang San went to your store to borrow a pack of cigarettes on credit, but Li Si knew about it first and kept an account for you first, and then others knew about it. Keep accounts, then Li Si can get a small red flower as a reward ~ This small red flower is generated by the blockchain system and has no value in itself, so you do not need to pay any cost for this small red flower??"< p>“Can Bitcoin be spent as money? How is it different from the banknotes we usually spend? "Gazi continued to ask.

"Bitcoin is a digital encrypted virtual currency. In principle, it has no value itself like our banknotes. However, banknotes have a credit guarantee from the state, so they have value. Bitcoin is the value formed by consensus among Bitcoin network users, and it has tradable properties, so it can be used to carry value. "What is said here is a bit profound. I don't know if I can understand it.

I continued to explain: "Banknotes can be printed infinitely. If more are printed, inflation will occur. When we were young, popsicles worth 1 cent were very good. , now you can’t eat with 1 yuan. Of course, there are many factors that affect inflation. The number of Bitcoins is fixed, and there is no possibility of unlimited over-issuance. However, different people have different judgments on their value, and coupled with the influence of supply and demand and investor sentiment, their prices are always fluctuating. ”

What is the difference between Bitcoin price fluctuations and stocks?

“So is speculating in Bitcoin just like speculating in stocks? Can you understand it this way? "Gazi seems to know a lot.

"In fact, there are some similarities, but there are also big differences. "I continued Gazi's topic: "The price of stocks always fluctuates around the valuation of companies, and there is government supervision in the stock market. Bitcoin itself has no value. It is priced entirely based on supply and demand and player valuations. It grows wildly without any government supervision. Therefore, it may have higher risks and higher returns than stocks. "

In the end, Gazi revealed the real purpose of today. He asked me: "Can I invest in blockchain projects? ”

Gazi is a typical example of those who don’t go to the Three Treasures Hall for anything. Although there is a large circle of people who are involved in both blockchain and Bitcoin, in fact, what he really cares about is “blockchain project investment” Is it reliable? "When these words came out, I was extremely shocked. Now the so-called blockchain investment projects have actually reached fourth- and sixth-tier cities and small towns!

As of now, there are only three types of blockchain investments. Situation: Mining, currency speculation, so-called blockchain projects.

Mining and currency speculation are still the main lines of the blockchain (pictures quoted from the Internet)

The so-called mining means mining by purchasing mining machines, etc. Equipment, mine virtual currency, and then sell it for cash to get returns. You can install the mining machine yourself, or you can find a mining pool to host it, but the core keys to profitability are "computing power" and "power consumption" as well as Investment in equipment. With the price of virtual currencies plummeting and the difficulty of miningWith the increase, the current mining income of many currencies is very unsatisfactory. Mining is obviously something only a very small number of investors who understand technology can do well, and my childhood friend Gazi obviously can’t do it.

As for "coin speculation", I have just introduced some differences between Bitcoin and stocks in the previous section. In principle, although they are both "buy low and sell high" operations, they are very different. Ordinary investors cannot determine the value of a virtual currency itself. The price is determined entirely by the relationship between supply and demand, which is somewhat similar to what we often call "market makers." On the other hand, the virtual currency trading market is extremely unstandardized, and fraud and hacker attacks often occur. The risk factor is much greater than investing in stocks. For the safety of my friends' funds, I am one of the ten thousand people who disagree with me and come to "speculate in coins"!

The "September Fourth Movement" stipulated that the issuance of virtual currency is illegal

In fact, in my opinion, most of the so-called investment projects in the market are essentially "illegal fund-raising" and "pyramid schemes." Some so-called blockchain investment projects attract investors into the circle through various packaging and inflammatory rhetoric, and then create the illusion of profitability by building a software and hardware ecosystem of issuing new coins + mining + currency speculation, and then finally run away. Our country's laws clearly stipulate that the issuance of virtual currencies is illegal.

Illegal pyramid schemes now wear the cloak of blockchain (picture quoted from the Internet)

And how to identify some pyramid schemes under the guise of blockchain? In fact, these pyramid schemes are also so-called Ponzi schemes, what we people often call "empty gloves." These so-called "direct sales" or "marketing" activities often have no actual products to circulate, and rely more on developing "downline" to ensure top-level profits. With the rise of the concept of blockchain, this MLM model has shown an intensification trend, and it even deceives people under the banner of state support for new technologies.

When Gazi asked, “Can blockchain projects be invested in?”, I realized the seriousness of the problem. Gazi is a typical young man from a small town, and his pursuit is his wife and children. But when faced with the attraction of "wealth", people often do inappropriate things. Mining and currency speculation are simply not suitable for him, let alone blockchain investment projects that are most likely "illegal financing" or "illegal pyramid schemes"!

I quickly dialed Gazi’s phone number and carefully conducted the above analysis??

❹ Which technology does blockchain use not include ( ) A cryptography B big data C P2P Network D Consensus Algorithm

Blockchain is a distributed shared accounting technology. What it wants to do is to allow all parties involved to establish a trust relationship at the technical level. Blockchain can be roughly divided into two levels: one is the underlying technology of the blockchain; the other is the upper-layer application of the blockchain, that is, the transformation, optimization or innovative application based on the blockchain. The core of blockchain...