两会区块链,第二届区块链大会

Ⅰ What are the prospects for the application of blockchain in the field of intellectual property?

During the National Two Sessions, the work report of the Supreme People's Court proposed: opening the judicial blockchain platform to support online copyright holders uploading Works, preserve evidence, and prevent and punish online plagiarism.
At present, the application of blockchain to the field of intellectual property has been increasingly recognized by the judiciary. The Supreme People's Court has issued five relevant policies in a row since 2018, recognizing the use of blockchain technology to solve problems such as the preservation, fixation and submission of evidence for intellectual property rights.
With the successive introduction of policies and continued judicial recognition, many enterprises and government units have begun to use third-party blockchain technology to strengthen their own intellectual property protection, ensuring that everything from creation to rights protection is traceable. Solve a series of problems such as evidence storage and collection, reduce the cost of rights protection, and improve the efficiency of rights protection.

II What exactly is the blockchain?

What exactly is the blockchain? In essence, blockchain is a distributed, decentralized network database system that will make the storage, update, maintenance, and operation of data different. Blockchain has four indispensable core technologies, namely: distributed storage, consensus mechanism, cryptography principles, and smart contracts.

Then let’s talk about how blockchain is different from traditional data processing to help everyone understand what blockchain is and give everyone a general understanding of blockchain. Cognition.

1. Data storage in blockchain: block chain data structure

In terms of data storage, blockchain technology utilizes "block chain data structure" To verify and store data.

What does the blockchain structure mean? Everyone has seen an iron chain, with one link within another. In fact, each link can be regarded as a block, and many links are linked together to form a blockchain.

How does this so-called "iron chain" store data? To put it simply, the difference between blockchain and ordinary stored data is that on blockchain, the data in the next block includes the data in the previous block.

Take reading as an example: when we read a book, we finish page 1, then page 2, page 3...
What about in the blockchain? If each block is marked with a page number, then the content on page 2 contains the content on page 1, the content on page 3 contains the content on page 1 and page 2...Page 10 contains The content of the first 9 pages is such a chain nested layer by layer. In this way, the most original data can be traced back. This is the traceability of the blockchain.

The "blockchain data structure" of blockchain makes it traceable, which is naturally suitable for many fields, such as: food traceability, drug traceability, etc. In this way, poisonThe probability of incidents such as milk powder, fake vaccines, and fake and substandard food will be greatly reduced, because once a problem occurs, through traceability, we can clearly know which link caused the problem, and accountability and redress will be clearer.

2. Data update in the blockchain: distributed node consensus algorithm

In terms of data update, blockchain technology uses the "distributed node consensus algorithm" to Generate and update data.

Every time a new block is generated (that is, when data is updated), an algorithm needs to be used to obtain the approval of more than 51% of the nodes in the entire network to form a new block. To put it bluntly, it is a vote, and it can be generated if more than half of the people agree, which makes the data on the blockchain non-tamperable.

Why do you say that? Let’s make an analogy: we compare the blockchain to a ledger, because it records data. In the traditional world, the bookkeeping power lies with the bookkeeper, and the ledger belongs to the bookkeeper alone. So in the blockchain, everyone owns this account book. If you want to update the account, you must vote. Only if more than half of the people agree can you update the account data.

In this process, we will involve several terms: distributed, node, consensus algorithm. These terms are actually very easy to understand:

Everyone Accounting (that is, everyone has a ledger, and the ledger is scattered in everyone's hands) is the so-called "distributed";

The accounting method that everyone discusses, votes for, and unanimously agrees on is The so-called "consensus algorithm";

Every person participating in accounting is a so-called "node".

3. Data maintenance in blockchain: cryptography

In the data maintenance stage, the difference of blockchain is that it uses cryptography to Ensure the security of data transmission and access.

The cryptographic principles applied in the blockchain mainly include: hash algorithm, Merkle hash tree, elliptic curve algorithm, and Base58. These principles actually ensure data security on the blockchain through a series of complex operations and conversions.

4. Data operations in the blockchain: smart contracts

A smart contract is a commitment agreement defined and automatically executed by a computer program. To put it bluntly, it is executed with code A set of transaction rules, similar to the current automatic repayment function of credit cards. If you turn this function on, you don't have to worry about anything. The bank will automatically deduct the money you owe when it expires.

The outstanding advantage of smart contracts is that they largely avoid a series of problems caused by trust.
Many of us have encountered the situation of being borrowed money: a friend who is short of money asks you to borrow 2,000 yuan and promisesThe next month he paid back the salary after the salary was paid, but the next month he found another excuse not to pay back, and it was pointless to drag it back and forth. We didn't have much money, but we were still friends. Even though you were depressed, let it go.

Then, after having a smart contract, he cannot default on his debt, because in the smart contract, once the terms in the contract are triggered, the code will automatically execute, whether he wants it or not, as long as he sends Once you have earned your salary and have money in your account, he has to pay you back.

To summarize the contents of this section, there are four indispensable core technologies in the blockchain, namely: distributed storage, consensus mechanism, cryptography principles, and smart contracts.

We can understand it this way: distributed storage corresponds to the data storage stage, the consensus mechanism corresponds to the data processing and update stage, cryptography corresponds to data security, and smart contracts correspond to data operational issues.

Ⅲ What is blockchain technology? What are the core components of blockchain technology?

From a technical point of view and an architectural point of view, I will tell you in popular language. Some understanding of blockchain.

What exactly is blockchain? Block chain, in a word, blockchain is a storage system, and the storage system is more detailed. Block chain is a distributed storage system without an administrator, and each node owns all data.

What do common storage systems look like?

First, let’s take a look at how to ensure high availability?

Ordinary storage systems usually use "redundancy" to solve high availability problems. As shown in the figure above, if the data can be copied into several copies and redundantly spread to multiple places, high availability can be ensured. If the data in one place is down, there will still be data in another place. For example, the master-slave cluster of MySQL has this principle, and the RAID of the disk also has this principle.

Two points that need to be emphasized here are: data redundancy often causes consistency problems

1. For example, in the master-slave cluster of MySQL, there will actually be a delay in reading and writing. Sometimes, it actually means that there is inconsistency between reading and writing for a short period of time. This is a side effect of data redundancy.

2. The second point is that data redundancy often reduces writing efficiency, because data synchronization also consumes resources. If you look at single-point writing, if two slave libraries are added, the writing efficiency will actually be affected. Ordinary storage systems use redundancy to ensure high data availability.

Then the second question is, can an ordinary storage system perform multiple writes?

The answer is yes, for example, take this picture as an example:

In fact, MySQL can do a master-slave synchronization of dual masters, a master-slave synchronization of dual masters, and two nodes. , and can be written at the same time. If you want to build a multi-machine room and multi-active data center, in fact, multi-machine room and multi-active data center also requires data synchronization. What should be emphasized here is multi-point writing, often leads to consistency issues of write-write conflicts. Taking MySQl as an example, assuming that the attribute of a table is an auto-increment ID, then the data in the database is now 1234, then one of the nodes writes and inserts a piece of data, then It may become 5, and then these 5 pieces of data are synchronized to another master node. Before the synchronization is completed, if another writing node also inserts a piece of data, a piece of data with an auto-incremented ID of 5 is also generated. data. Then, after it is generated, it is synchronized to another node, and then when the synchronized data arrives, it will conflict with the two local 5s, and the synchronization will fail, which will cause write consistency conflicts. This problem will occur if there are multiple writes.

How to ensure consistency when writing multiple points?

Weixin's "Swan Master Class" will give you more technical work

IV [Blockchain] What is Blockchain (2)

Because the current blockchain field is filled with a large number of funds and air coins. Moreover, when talking about blockchain, it inevitably involves topics such as finance, investment or speculation. Investment is risky and decisions need to be made with caution. Friends, please keep your eyes open and proceed at your own risk.

In this famous paper, Satoshi Nakamoto succinctly discussed how to implement a complete peer-to-peer electronic currency system that does not require a financial institution.

However, he did not explain clearly why he needed to do this. But when I think of the famous quote that he forever minted in the first Bitcoin block: "The Times 03/Jan/2009 Chancellor on brink of second lout for banks. The Chancellor is on the brink of second lout for banks." We can't help but follow the clues and ponder:

In fact, the history of modern human financial institutions, or in other words - banks, is not very long. The word Bank in English originated from the Italian BanCa, which originally meant a bench used for transactions. The prototype of modern banking originated in Venice, Italy in the 13th century. Of course, in almost the same era, in the far East, in the Song Dynasty of China, banks and banks with usury and interest-free deposit businesses also appeared.

Originally, it was an almost natural process for gold and silver to become the world's recognized currency. I still remember Marx once said:

However, since the emergence of banks, bankers were delighted to find that the banknote they wrote was almost equivalent to gold and silver, and also played the role of currency. effect. Therefore, relying on people's trust in banks as financial institutions, bankers can conjure money out of thin air. As long as everyone does not come to exchange the silver notes into silver at the same time, the bank that has deposited 100,000 taels of silver can issue 110,000 taels of silver notes, 100,000 to the depositor, and 10,000 to spend by yourself! even more! !!

We can abstract the development process of this story:

Although, later the coinage power was taken back from private banks to the central banks of various governments. But what do central banks do? Not to mention the stupid behavior of the stupid Kuomintang government that crazily issued legal currency and destroyed the economy (100 legal currency could buy two cows in 1937, one fish in 1945, and two grains of rice in 1948. Of course, it was completely abolished in 1949. ), let’s take a look at what the United States, which is the leader in the world economy, does today:

So, in 1933, one ounce of gold was worth $20; in 1944, one ounce of gold was anchored at $35, until August 15, 1971; in 1973, one ounce of gold exceeded $100; in 1975, one ounce of gold was about $150; in 2021, one ounce of gold has exceeded $1,800! From 1933 to 1944, the American people were forced to pay nearly double the price for 10 years, which finally made the U.S. dollar the world currency; and then from 1971 to today, 50 times, 50 years!

Now everyone knows where Wang Er Mazi’s rice and vegetables come from. But, so what? After all, the world cannot do without financial institutions, and it also cannot do without the largest and most awesome company. It is not too outrageous to make do with Wang Ermazi to take care of it. How about letting him eat the rice and vegetables?

But cryptographer and programmer Mr. Satoshi Nakamoto obviously has different opinions. When he registered on the P2P Foundation website where he published the paper "Bitcoin: A Peer-to-Peer Electronic Cash System", the birthday he filled in was April 5, 1975. Now many people They all speculated that writing about this date must have some ulterior meaning!

So, in short, we need to remember that Satoshi Nakamoto’s purpose of inventing Bitcoin was to realize a complete peer-to-peer electronic currency system that does not require a financial institution.

And this is the driving force behind the birth of the entire blockchain world that is now turbulent.

No one of us can accurately explore what Mr. Satoshi Nakamoto was thinking at that time. But this "sociological financial experiment" started by him is still in full swing after more than 10 years...

IV Blockchain on Baidu What has been done

Blockchain is still in a very early stage

At the two sessions, Robin Li’s speech mainly focused on the network’s open platforms such as PaddlePaddle, DuerOS and Apollo, as well as the network’s On autonomous driving. In addition to the Internet and technology, the boss also talked about life and the environment.Regarding environmental-related smoking ban issues, it is recommended that national tobacco control regulations be promulgated.

In October 2017, Internet Finance officially joined the Hyperledger open source project of the Linux Foundation. Other core board members include IBM, Intel and JPMorgan Chase, etc.

Jack Ma: I want to know what Bitcoin can bring to society

At the two sessions, Jack Ma... Oh, I'm sorry, Comrade Jack Ma, who didn't want to wear a red hat, did not attend the two sessions.

So, let’s review what Jack Ma said when he evaluated Bitcoin:

“I don’t have much interest in Bitcoin. What I want to know is whether Bitcoin can What will it bring to society? Having said that, I think Bitcoin technology is very powerful, but we must be very careful when treating Bitcoin."

Although Jack Ma is very cautious about Bitcoin itself, he also said that he Don't know much about Bitcoin. But regarding "Bitcoin technology" or "blockchain", Jack Ma's view is that it is "very powerful."

VI What is blockchain technology? What is blockchain? A chain data structure composed of sequential connections, and a cryptographically guaranteed distributed ledger that cannot be tampered with or forged.

Broadly speaking, blockchain technology uses block chain data structures to verify and store data, uses distributed node consensus algorithms to generate and update data, and uses cryptography to ensure data transmission and access. It is a new distributed infrastructure and computing method that uses smart contracts composed of automated script codes to program and operate data securely.

[Infrastructure]

Generally speaking, the blockchain system consists of data layer, network layer, consensus layer, incentive layer, contract layer and application layer composition. Among them, the data layer encapsulates the underlying data blocks and related basic data and basic algorithms such as data encryption and timestamps; the network layer includes distributed networking mechanisms, data dissemination mechanisms, and data verification mechanisms; the consensus layer mainly encapsulates network nodes Various consensus algorithms; the incentive layer integrates economic factors into the blockchain technology system, mainly including the issuance mechanism and distribution mechanism of economic incentives; the contract layer mainly encapsulates various scripts, algorithms and smart contracts, and is the core of the blockchain The basis of programmable features; the application layer encapsulates various application scenarios and cases of the blockchain. In this model, the chain block structure based on timestamps, the consensus mechanism of distributed nodes, economic incentives based on consensus computing power, and flexible programmable smart contracts are the most representative innovations of blockchain technology.

Extended information:

[Blockchain core technology]

Blockchain mainly solves the trust and security issues of transactions, so it addresses this issue Four technological innovations:

1. Distributed ledger meansEasy Accounting is completed by multiple nodes distributed in different places, and each node records complete accounts, so they can all participate in supervising the legality of transactions and can also jointly testify for them.

The uniqueness of blockchain's distributed storage is mainly reflected in two aspects: First, each node of the blockchain stores complete data according to the block chain structure. Traditional distributed storage generally stores The data is divided into multiple parts for storage according to certain rules. Second, the storage of each node in the blockchain is independent and has equal status, relying on the consensus mechanism to ensure the consistency of storage, while traditional distributed storage generally synchronizes data to other backup nodes through the central node.

No node can record ledger data independently, thus avoiding the possibility of a single bookkeeper being controlled or bribed to record false accounts. Also because there are enough accounting nodes, theoretically speaking, the accounts will not be lost unless all nodes are destroyed, thereby ensuring the security of the accounting data.

2. Asymmetric encryption and authorization technology. Transaction information stored on the blockchain is public, but account identity information is highly encrypted and can only be accessed with authorization from the data owner. , thus ensuring data security and personal privacy.

3. The consensus mechanism is how all accounting nodes reach a consensus to determine the validity of a record. This is both a means of identification and a means of preventing tampering. Blockchain proposes four different consensus mechanisms, which are suitable for different application scenarios and strike a balance between efficiency and security.

The consensus mechanism of the blockchain has the characteristics of "the minority obeys the majority" and "everyone is equal". "The minority obeys the majority" does not entirely refer to the number of nodes, but can also be the computing power and the number of shares. Or other characteristic quantities that the computer can compare. "Everyone is equal" means that when a node meets the conditions, all nodes have the right to give priority to the consensus result, which will be directly recognized by other nodes and may eventually become the final consensus result.

4. Smart contracts. Smart contracts are based on these trustworthy and non-tamperable data and can automatically execute some predefined rules and terms. Take insurance as an example. If everyone's information (including medical information and risk occurrence information) is true and trustworthy, it will be easy to automate claims settlement in some standardized insurance products.

In the daily business of insurance companies, although transactions are not as frequent as those in the banking and securities industries, the reliance on trusted data continues unabated. Therefore, the author believes that using blockchain technology from the perspective of data management can effectively help insurance companies improve their risk management capabilities. Specifically speaking, it is mainly divided into risk management of policyholders and risk supervision of insurance companies.

Blockchain-Network

Ⅶ Tutorial for getting started with blockchain

However, the simple and easy-to-understand introductory article is very few. What exactly blockchain is and what makes it special is rarely explained.
Next, I will comeTry to write the best blockchain tutorial. After all, it is not difficult. The core concept is very simple and can be explained clearly in a few sentences. I hope that after reading this article, you will not only understand the blockchain, but also understand what mining is, why mining is getting more and more difficult, and other issues.
It should be noted that I am not an expert in this area. Although I have been paying attention to it for a long time, my detailed understanding of blockchain started at the beginning of this year. You are welcome to correct any errors or inaccuracies in the article.
1. The essence of blockchain
What is blockchain? In a word, it is a special distributed database.
First of all, the main function of blockchain is to store information. Any information that needs to be saved can be written to the blockchain and read from it, so it is a database.
Secondly, anyone can set up a server, join the blockchain network, and become a node. In the world of blockchain, there is no central node. Every node is equal and stores the entire database. You can write/read data to any node, because all nodes will eventually be synchronized to ensure that the blockchain is consistent.
2. The biggest features of blockchain
Distributed databases are not a new invention, and there have been such products on the market for a long time. However, blockchain has a revolutionary feature.
Blockchain has no administrator, it is completely centerless. Other databases have administrators, but blockchain does not. If one wanted to add auditing to the blockchain, it would not be possible because it is designed to prevent the emergence of a central authority.
It is precisely because it is unmanageable that blockchain can be uncontrollable. Otherwise, once big companies and large groups control the management, they will control the entire platform, and other users will have to take orders from them.
However, without an administrator, everyone can write data into it. How can we ensure that the data is trustworthy? What if it is modified by a bad person? Please read on, this is the wonderful thing about blockchain place.
3. Block
Blockchain is composed of blocks. Blocks are much like database records. Every time data is written, a block is created.
Each block contains two parts.
Head: records the characteristic values ​​of the current block
Body: actual data
The block header contains multiple characteristic values ​​of the current block.
Generation time
Hash of the actual data (i.e. block body)
Hash of the previous block
...
Here, you need to understand what a hash is , which is necessary to understand blockchain.
The so-called hashing means that the computer can calculate a characteristic value of the same length for any content. The hash length of the blockchain is 256 bits, which means that no matter what the original content is, a 256-bit binary number will be calculated in the end. And it can be guaranteed that as long as the original content is different, the corresponding hash must be different.
For example, the hash of the string 123 is (hexsystem), converted to binary is 256 bits, and only 123 can get this hash. (Theoretically, it is possible for other strings to get this hash, but the probability is extremely low and can be approximated as impossible.)
Therefore, there are two important inferences.
Corollary 1: The hash of each block is different, and the block can be identified by the hash.
Corollary 2: If the content of the block changes, its hash will definitely change.
4. The non-modifiable nature of Hash
Blocks and hashes have a one-to-one correspondence, and the hash of each block is calculated based on the block header (Head). That is to say, the characteristic values ​​​​of the block header are connected together in order to form a very long string, and then the hash is calculated on this string.
Hash = SHA256 (block header)
The above is the calculation formula of block hash. SHA256 is the hash algorithm of the blockchain. Note that this formula only contains the block header and not the block body. In other words, the hash is uniquely determined by the block header.
As mentioned before, the block header contains a lot of content, including the hash of the current block body. , and the hash of the previous block. This means that if the content of the current block body changes, or the hash of the previous block changes, it will definitely cause the hash of the current block to change.
This point has great significance for blockchain. If someone modifies a block, the hash of the block changes. In order for subsequent blocks to still be connected to it (because the next block contains the hash of the previous block), the person must modify all subsequent blocks in sequence, otherwise the modified block will be removed from the blockchain . Due to the reasons mentioned later, hash calculation is very time-consuming, and it is almost impossible to modify multiple blocks in a short period of time, unless someone controls more than 51% of the computing power of the entire network.
It is through this linkage mechanism that the blockchain ensures its own reliability. Once the data is written, it cannot be tampered with. This is just like history, what happened happened, and it can’t be changed from now on.
Each block is connected to the previous block, which is where the name blockchain comes from.
5. Mining
Since synchronization between nodes must be ensured, the adding speed of new blocks cannot be too fast. Just imagine, you have just synchronized a block and are preparing to generate the next block based on it, but at this time, another node generates a new block, and you have to give up half of the calculations and synchronize again. Because each block can only be followed by one block, you can only generate the next block after the latest block. So, you have no choice but to sync as soon as you hear the signal.
So, the inventor of the blockchain, Satoshi Nakamoto (this is a pseudonym, and his true identity is still unknown) deliberately made it difficult to add new blocks. His design is that on average, the entire network can generate a new block every 10 minutes, which is only six per hour.
This output speed is not achieved through commands, but by deliberately setting up massive calculations. In other words, only through extremelyIt takes a lot of calculations to get the effective hash of the current block and add the new block to the blockchain. Because the amount of calculation is too large, it cannot be done quickly.
This process is called mining, because the difficulty of calculating a valid hash is like finding a grain of sand that meets the conditions among the sand in the world. The machine that calculates hashes is called a mining machine, and the person who operates the mining machine is called a miner.
6. Difficulty coefficient
After reading this, you may have a question. People say that mining is difficult, but isn’t mining just about using a computer to calculate a hash? This is the strength of computers. How could it be? It becomes very difficult, why can’t it be calculated?
It turns out that not just any hash can be used, only hashes that meet the conditions will be accepted by the blockchain. This condition is particularly harsh, causing most hashes to fail to meet the requirements and must be recalculated.
It turns out that the block header contains a difficulty coefficient (difficulty), which determines the difficulty of calculating the hash. For example, the difficulty coefficient of the 100,000th block is 14484.16236122.
The blockchain protocol stipulates that the target value (target) can be obtained by dividing the difficulty coefficient by a constant. Obviously, the greater the difficulty coefficient, the smaller the target value.
The validity of the hash is closely related to the target value. Only hashes smaller than the target value are valid, otherwise the hash is invalid and must be recalculated. Since the target value is very small, the chance that the hash is smaller than this value is extremely slim, and it may be calculated 1 billion times before it is considered a hit. This is the fundamental reason why mining is so slow.
As mentioned earlier, the hash of the current block is uniquely determined by the block header. If the hash of the same block needs to be calculated repeatedly, it means that the block header must keep changing, otherwise it is impossible to calculate different hashes. All feature values ​​in the block header are fixed. In order to make the block header change, Satoshi Nakamoto deliberately added a random item called Nonce.
Nonce is a random value. The role of the miner is actually to guess the value of Nonce so that the hash of the block header can be smaller than the target value so that it can be written to the blockchain. Nonce is very difficult to guess. At present, we can only use trial and error one by one through exhaustive methods. According to the protocol, Nonce is a 32-bit binary value, which can reach a maximum of 2.147 billion. The Nonce value of the 100,000th block is 274148111. It can be understood that the miner started from 0 and calculated 274 million times before obtaining a valid Nonce value so that the calculated hash can meet the conditions.
If you are lucky, you may find Nonce in a while. If you are unlucky, you may have calculated it 2.147 billion times without finding the Nonce, that is, it is impossible to calculate a hash that meets the conditions for the current block body. At this time, the protocol allows miners to change the block body and start a new calculation.
7. Dynamic adjustment of difficulty coefficient
As mentioned in the previous section, mining is random and cannot be guaranteed to be just right.It takes ten minutes to produce a block. Sometimes it is done within a minute, and sometimes there may be no results for several hours. Overall, with the improvement of hardware equipment and the increase in the number of mining machines, the computing speed will definitely become faster and faster.
In order to keep the output rate constant at ten minutes, Satoshi Nakamoto also designed a dynamic adjustment mechanism for the difficulty coefficient. He stipulated that the difficulty factor should be adjusted every two weeks (2016 blocks). If the average block generation speed in these two weeks is 9 minutes, it means that it is 10% faster than the legal speed, so the next difficulty factor will be increased by 10%; if the average block generation speed is 11 minutes, it means It is 10% slower than the legal speed, so the difficulty factor of the next step must be lowered by 10%.
The difficulty coefficient is adjusted higher and higher (the target value is getting smaller and smaller), which makes mining more and more difficult.
8. Forks of the blockchain
Even if the blockchain is reliable, there is still an unresolved problem: if two people write data to the blockchain at the same time, that is to say, two people write data to the blockchain at the same time. Blocks join because they are connected to the previous block, forming a fork. Which block should be adopted at this time?
The current rule is that new nodes always adopt the longest blockchain. If there is a fork in the blockchain, it will look at which branch is behind the fork to reach 6 new blocks first (called six confirmations). Based on a block calculation of 10 minutes, it can be confirmed in one hour.
Since the generation speed of new blocks is determined by computing power, this rule means that the branch with the most computing power is the authentic blockchain.
9. Summary
Blockchain, as an unmanaged distributed database, has been running for 8 years since 2009 without major problems. This proves it works.
However, in order to ensure the reliability of data, blockchain also has its own price. The first is efficiency. You have to wait at least ten minutes to write data to the blockchain. All nodes synchronize the data, which requires more time. The second is energy consumption. The generation of blocks requires miners to perform countless meaningless calculations. This is Very energy consuming.
Therefore, the applicable scenarios of blockchain are actually very limited.
There is no management authority that all members trust
The written data does not require real-time use
The benefits of mining can make up for its own costs
If the above conditions cannot be met, then the traditional database is Better solution.
Currently, the largest application scenario (and possibly the only application scenario) of blockchain is the cryptocurrency represented by Bitcoin.

Ⅷ What is Blockchain

In the simplest terms, a 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 the process of our bank debit card transaction:

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 validate the transaction and add it to the ledger (the added records are called "blocks"). This has some important benefits, as there is no centralized authority that can manipulate records. Hackers accessing one ledger won't be a big problem because other ledgers can easily verify it.

On the other hand, 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 send a message to everyone in the network saying "I am sending Xiao Ming 2 Bitcoins" and they all record the transaction.

The future of blockchain, how will it change our lives?

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

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

This may sound 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 a computer could be held in our hands and that we could buy cars, make payments, and watch movies on it, we would definitely be considered a genius.Fang Night Tales.

Although the impact of blockchain may not be as obvious as the Internet, nor as tangible as mobile phones, blockchain will effectively solve many worries in daily life. Such as intermediaries cheating people, transaction delays, etc. In our current lives, middlemen are everywhere and we take them for granted as a part of life. If one day these intermediaries cease to exist, you will find that the world will become a different place.

Imagine that by 2040, blockchain may become a mature and widely used 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

Ⅸ What exactly is blockchain? Decrypt the concept of blockchain