区块链交易可追溯的解释是什么,区块链交易可追溯的解释是

区块链交易可追溯的解释是指，通过区块链技术，可以记录和追溯一笔交易的历史信息。拓展3个相关关键词分别是：区块链技术、交易安全和可追溯性。

一、区块链技术：区块链技术是一种分布式数据库技术，它可以将数据分布在网络中的各个节点上，而不是集中在一个地方存储。区块链技术是一种分布式账本技术，可以记录每一笔交易的历史信息，并且不会被篡改。它的优点是可靠性强，安全性高，可以有效防止数据被篡改和窃取。

二、交易安全：区块链技术可以有效保障交易安全，因为它可以记录每一笔交易的历史信息，并且不会被篡改。此外，区块链技术还可以提高交易的安全性，因为它可以检测到潜在的欺诈行为，并且可以有效防止数据被篡改和窃取。

三、可追溯性：区块链技术可以记录每一笔交易的历史信息，因此可以实现可追溯性。区块链技术可以提供一个安全的环境，让用户可以追溯每一笔交易的历史信息，从而提高交易的安全性和可靠性。

以上就是区块链交易可追溯的解释以及拓展3个相关关键词的介绍，包括：区块链技术、交易安全和可追溯性。区块链技术可以有效记录每一笔交易的历史信息，并且不会被篡改，从而保证交易的安全性，并且可以实现可追溯性，提高交易的安全性和可靠性。

A. 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, the probability of tainted milk powder, fake vaccines, and fake and substandard food incidents will be greatly reduced, because once a problem occurs, through traceability, we can clearly know which link caused the problem, and accountability and recovery 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.

WhyWhat do you mean? 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 borrows 2,000 yuan from you and promises to pay back the money after the salary is paid next month, but next month he finds other excuses. Also, dragging it around would be pointless. 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, and the consensus mechanism corresponds to data processing.At this stage of updating, cryptography corresponds to data security, and smart contracts correspond to data operation issues.

B. Blockchain knowledge: What are the characteristics of blockchain?

Blockchain knowledge: What are the characteristics of blockchain
Nowadays, blockchain has It has become an area of ​​national concern, and many companies have already conducted in-depth research on the implementation of this technology. However, there are still a large number of people who are not familiar with the concepts related to blockchain technology. Recently, Viking Research Institute and Jiazi Think Tank jointly produced the "Blockchain Industry Dictionary". Bianews is authorized as a media partner and will popularize blockchain-related knowledge for everyone every day.
Today, Bianews will bring you a little knowledge about blockchain Chapter (2): Characteristics of blockchain
1. Anonymous/Anonymous Since the data exchange between nodes in the blockchain follows The algorithm is fixed and predictable, so the blockchain network is trustless and can exchange data based on addresses rather than personal identities.
2. Autonomous/Autonomous blockchain adopts a mechanism based on consensus, allowing all nodes in the entire system to exchange data, record data, and update data freely and securely in a trustless environment. Any human intervention will doesn't work.
3. Openness/Openness The blockchain system is open, and any node can have the general ledger of the entire network. In addition to the private information of the parties directly related to the data being encrypted through asymmetric encryption technology, the blockchain The data is open to all nodes, so the entire system information is highly transparent.
4. Programmable/Programmable The digital nature of distributed ledgers means that blockchain transactions can be associated with computational logic and are programmable in nature. Therefore, users can set algorithms and rules that automatically trigger transactions between nodes.
5. Traceability/Traceability The blockchain stores all historical data after the creation block through the block data structure. Any piece of data on the blockchain can be traced back to its origin through the chain structure.
6. Cannot be tampered with/Tamper Proof. After the blockchain information is added to the blockchain through consensus, it is jointly recorded by all nodes, and is guaranteed to be interconnected through cryptography. The difficulty and cost of tampering are very high.
7. Collectively Maintain/Collectively Maintain The blockchain system is jointly maintained by all nodes with maintenance functions. All nodes can query blockchain data and develop related applications through public interfaces.
8. Permissionless/Permissionless means that all nodes can request that any transaction be added to the blockchain, but the transaction can only be carried out if all users consider it legal.

C. The significance of blockchain technology in anti-counterfeiting and traceability

——YinChain answer:

Blockchain can realize data traceability and non-tampering because it is based on a distributed database established by cryptographic links, thus forming a data source that cannot be tampered with. Therefore, complete information records can be achieved in the entire process of products from production to circulation, providing comprehensive product data information to regulatory authorities, allowing them to complete product quality inspection and data interconnection and mutual sharing more efficiently. In this process, blockchain can solve Four issues:

First, information cannot be tampered with, consensus is reached and trust is established. In the network nodes composed of various participants, the business process forms data records. In the product logistics, warehousing, and production links, including raw material sources, processing, assembly and other information are stored in the blockchain network, providing regulatory authorities and cooperative enterprises with Or organizations provide data information for each link.

Second, the process is open and transparent. To achieve product anti-counterfeiting and circulation in the business process, identification chips can be implanted into the product and registered on the blockchain so that it has a digital identity, and then all the information of this digital identity can be recorded through a jointly maintained ledger. Such as source, circulation, etc., to achieve verification effect.

Third, save costs and improve efficiency. The data recorded on the blockchain are kept confidential, and the regulatory authorities store, transmit, verify, and analyze product information, and transfer it between different departments to achieve unified vouchers, full-process records, and corporate credit reporting, which can effectively solve the problem. Issues such as multi-party participation, information fragmentation, and repeated review of circulation links.

Fourth, information sharing. The circulation of enterprise product certification relies on the interconnection of public data resources among departments and institutions such as commerce, customs, quality inspection, industry and commerce, and banks. Under the review environment established by the blockchain, all departments obtain information simultaneously and establish a supply chain-based The credit evaluation mechanism is organically connected with various supply chain platforms to disclose and share information such as credit ratings, credit records, risk warnings, illegal and dishonest behaviors, etc.

The disadvantages of traditional anti-counterfeiting traceability have become very obvious. Anti-counterfeiting traceability has always been an important scenario in blockchain applications. Typical Ruyin Chain also starts from the anti-counterfeiting traceability scenario, hoping to create a blockchain suitable for commercial use. .

Compared with the traditional centralized anti-counterfeiting traceability technology, Yinlian uses the underlying technology of the blockchain, and the merchants produce the anti-counterfeiting codes themselves, eliminating the trust problem of cheating by the middle anti-counterfeiting dealers. The main process is as follows:

D. What are the main data security measures of the supply chain blockchain?

The main data security measures include identity authentication and access control , data encryption, data backup, etc.

E. What exactly is blockchain

Let’s talk about some basic concepts first.

The network said that blockchain is a new usage model of computer technologies such as distributed data storage, point-to-point transmission, consensus mechanisms, and encryption algorithms. It is essentially a decentralized database, and as the underlying technology of Bitcoin, it is a series of data blocks generated by cryptography.

We tried to translate "what is blockchain" intoTranslated into "human language".

The definition refers to the "decentralized database" nature of blockchain3354. This is very different from the traditional "centralized database" in storage, update and operation.

A centralized database can be thought of as having this shape:

For example, if I want to use Alipay to pay a Taobao seller, all data requests from when I make money to when he receives the money will be centrally processed by Alipay. The advantage of this data structure is that as long as Alipay is responsible for the efficient and safe operation of the system, others can unconditionally believe it without worrying; the disadvantage is that if there is a problem with Alipay, such as being hacked, the server being burned, a traitor appearing, and the company running away (Of course, the possibility of the above is extremely low), the balance details and other information in our Alipay will be confused.

Then some people think that this kind of low-probability event can use any technical means to avoid individual risks, and not only hand over the data to a centralized organization. For example, everyone can store and process data.

The database structure may look like this:

This picture is a schematic structural diagram of a "distributed database". Each point is a server, they all have equal rights to record and calculate data, and information is spread point-to-point. At first glance, it seems that it can indeed resist the risk caused by the crash of a certain node, but it is also very confusing and inefficient intuitively. Who will handle my information, and who has the final say on the results?

At this time, the "consensus mechanism" in the definition of blockchain comes into play. The consensus mechanism mainly "stipulates" the following things: who will process a data request (what qualifications are required); who will verify the results (to see if he has handled it well); how to prevent processors and verifiers from colluding with each other, etc.

Some people may like to be questioned when a "rule" is made. In order to form a stronger consensus, in addition to making the rules more reasonable, they must also be more attractive so that people are interested and motivated to participate in data processing. This involves the incentive mechanism of the public chain. We will start again later when we discuss the classification of blockchain and the role of digital currencies.

When we hand over a transaction to a distributed network, there is also a "psychological threshold": there are so many nodes that can process information, and I don't know any of them (unlike Alipay, if it hurts me, I can go and file a lawsuit against it). They all have my data, why should I trust them?

At this time, encryption algorithm (the last descriptive word in the definition of blockchain) comes on stage.

In the blockchain network, the data requests we send will be encrypted according to cryptographic principles into a string of characters that the recipient cannot understand at all. Behind this encryption method is the support of a hash algorithm.

Hash algorithms can quickly convert any type of data into hash values. This change is one-way irreversible, deterministic, random, and anti-collision. Because of these characteristics, the person handling my data request could record the information for me, but they had no idea who I was or what I was doing.

So far, the working principle of the decentralized network has been introduced. But we seem to have overlooked one detail. The previous diagram is a net. where are the pulleys and chains? Why do we call it blockchain?

To understand this matter, we need to clarify a few knowledge points first:

The previous picture is actually a "macro" database perspective, showing the basic rules and processes of the blockchain system for processing information. . And specifically at the "micro" data log level, we will find that the ledger is packaged, compressed, stored in blocks, and strung together in chronological order to form a "chain structure", like this:

Figure Each ring in can be regarded as a building block, and many links are linked together to form a blockchain. Blocks store data, unlike ordinary data storage: on a blockchain, the data in a later block contains the data in the previous block.

In order to academically explain the fields of each part of the data in the block, we tried to use a book metaphor to describe what a blockchain data structure is.

Usually, when we read a book, we read the first page, then the second and third pages. The spine is a physical existence that fixes the order of each page. Even if the book is scattered, the order of each numbered page can be determined.

Inside the blockchain, each block is marked with a page number, the second page contains the content of the first page, the third page contains the content of the first and second pages. The tenth page contains the previous Nine pages of content.

It is such a nested chain that can be traced back to the original data.

This brings up an important attribute of blockchain: traceability.

When the data in the blockchain needs to be updated, that is when new blocks are generated in sequence, the "consensus algorithm" comes into play again. This algorithm stipulates that a new block can only be formed if it is recognized by more than 51% of the nodes in the entire network. To put it bluntly, it is a matter of voting, and it can be elected if more than half of the people agree. This makes the data on the blockchain difficult to tamper with. If I were to force a change, there would be too many people to bribe and the cost would be too high to be worth it.

This is what people often call the "non-tamperable" feature of blockchain.

Another reason why blockchain gives people a sense of trust is because of "smart contracts."

Smart contracts are commitment agreements defined and automatically executed by computer programs. It is a set of transaction rules executed by code, similar to the current automatic repayment function of credit cards. If you turn on this function, you don’t have to worry about anything. The bank will automatically deduct the money you owe when it is due.

When your friend borrows money from you but doesn't remember to pay it back, or makes excuses not to pay it back, smart contracts can prevent breach of contract. Once the terms in the contract are triggered, such as when it is time to pay back the money, or there is a limit in his account, the code will automatically execute, and the money he owes you will be automatically transferred back whether he wants it or not.

Let’s briefly summarize. Blockchain technology is mainly decentralized, difficult to tamper with, and traceable, which represents more security and trustlessness. But it also brings new problems: redundancy and inefficiency, which requires many nodes to agree with the rules and actively participate.

This concludes the "drying" section. Next, let’s talk about unofficial history and the official history of blockchain.

A new technology is often used to serve a certain task.

Or goals. So where was the blockchain originally used?Who came up with it first?

Let's go back to 2008.

On September 21, Wall Street investment banks collapsed one after another, and the Federal Reserve announced that it would convert the only two remaining investment banks (Goldman Sachs Group and Morgan Stanley) into commercial banks; it hoped to survive the financial crisis by absorbing savings. On October 3, the Bush administration signed a $700 billion financial rescue package.

Twenty-eight days later, on November 1, 2008, a new post appeared in a cryptography mailing group: "I am developing a new electronic currency system that is completely peer-to-peer and does not require a third party. Three-party trust institution." The text of the post is a paper titled "Bitcoin: A Peer-to-Peer Electronic Cash System", signed by Satoshi Nakamoto.

The paper explains the design of this peer-to-peer electronic cash system with a more rigorous logic. It first discusses the problem that financial institutions are subject to "trust based" (based on credit), and then explains step by step how to achieve "no third-party agency" , and cleverly solved the technical problems left by the predecessors.

Two months later, Satoshi Nakamoto released the first version of the open source Bitcoin client and mined 50 Bitcoins for the first time. The block that generated the first batch of Bitcoins is called the "Genesis block". The genesis block was compiled into block 0 and was not uploaded to the chain. It took Satoshi Nakamoto 6 days to mine this block. This also sparked discussion in the bitcointalk forum. Bitcoin "believers" thought of the Bible, "God created the heavens and the earth in six days, and then rested on the seventh day."

Although concepts such as decentralized, token, and economy did not appear in the paper, Satoshi Nakamoto explained in detail the role of blocks and chains in the network. working principle. So, there is Block Chain.

This paper later became the "Bible" of the "Bit Cult", technology became the cornerstone of faith, and developer documentation became the "Code of Hammurabi".

After that, Bitcoin realized the first real-life payment by exchanging pizza, WikiLeaks, whose account was blocked by the US government, miraculously survived by relying on Bitcoin, Satoshi Nakamoto's "decentralization" and retirement, and the appearance of the real and the fake A series of legends such as and refutation of rumors, combined with the expectations, imagination and speculation of later generations, became "Bible stories".

There are also people who are not satisfied with the world described in the "Old Testament" and start new sects, write the doctrines into white papers, and tell the story of their faith in the ten years after Bitcoin. Just like the writing of the 66 books of the Bible spanned 1,500 years, and after 2,000 years of interpretation, Christianity has divided into 33,000 branches.

CoinMarketCap shows that there are more than 4,900 types of digital currencies, and the overall digital currency market size is nearly 140 million yuan. Bitcoin is stillLeading the entire digital currency market with a market share of 66%, the price has recently been hovering around US$7,200 per coin.

So many currencies have different functions and are divided into different categories: digital currencies represented by Bitcoin are positioned as "digital gold" and have certain value storage and hedging characteristics; Ethereum The digital currency represented by Bitcoin has become the "operational fuel" in its network system; the stable currency represented by USDT and Libra has good payment properties due to its low volatility; the digital currency issued by the central bank represented by DCEP will definitely To a certain extent, it replaces M0, allowing commercial institutions and ordinary people to receive and pay without delay when they are out of cash and disconnected from the Internet.

It can be seen that after 10 years of development of blockchain technology, the first and largest application is digital currency.

Digital currency has also become an attractive reward for participants to maintain the public chain.

So besides digital currency, where else can blockchain technology be used?

Let us recall what the essence of blockchain is—a decentralized database, and its corresponding characteristics: traceability, publicity, anonymity, and tamper-proofing. In theory, you can try to use blockchain to transform traditional scenarios that use centralized databases to see if they are suitable.

Next, let’s talk about several industries and scenarios where blockchain has been successfully implemented:

Blockchain can prove the existence of a certain file or digital content at a specific time through hash timestamps, providing judicial authentication, Identity proof, property rights protection, anti-counterfeiting traceability, etc. provide perfect solutions

In the field of anti-counterfeiting traceability, blockchain technology can be widely used in various fields such as food and medicine, agricultural products, alcohol, and luxury goods through supply chain tracking.

Give two examples.

Blockchain can allow government data to be run, greatly streamlining service processes

The distributed technology of blockchain can allow government departments to be centralized on one chain, and all service processes are delivered to smart contracts, and the workers only need to be in one department Through identity authentication and electronic signature, smart contracts can be automatically processed and transferred, and all subsequent approvals and signatures can be completed in sequence.

Blockchain invoices are the earliest use of blockchain technology in China. The tax department launched the "Tax Chain" platform for blockchain electronic invoices. The tax department, the issuer, and the payee join the "Tax Chain" network through unique digital identities, truly realizing "instant invoicing for transactions" and "instant reimbursement after invoicing" - in seconds Level invoicing and minute-level reimbursement accounting significantly reduce tax collection and management costs, and effectively solve problems such as data tampering, over-reporting of one ticket, and tax evasion.

Poverty alleviation is another practical application of blockchain technology. Utilize the characteristics of openness, transparency, traceability, and non-tampering of blockchain technology to achieve transparent use, precise investment, and efficient management of poverty alleviation funds.

Give two examples as well.

The eID network identity operation agency guided by the Third Research Institute of the Ministry of Public Security is jointly developing a "digital identity chain" with Gongyilian, which will be issued to Chinese citizens based on the citizen's identity number as the root and cryptographic algorithm. Since it was put into operation, the eID digital identity system has served the entire population of 100 million eIDs.Life cycle management effectively alleviates the problems of personal identity information being fraudulently used, abused and privacy leaked.

Odaily Planet Daily compiled 5 identity chain projects registered with the Cyberspace Administration of China

Blockchain technology naturally has financial attributes

In terms of payment and settlement, under the blockchain distributed ledger system, there are many markets Participants jointly maintain and synchronize a "general ledger" in real time. In just a few minutes, they can complete payment, clearing, and settlement tasks that currently take two or three days to complete, reducing the complexity and cost of cross-bank and cross-border transactions. At the same time, the underlying encryption technology of the blockchain ensures that participants cannot tamper with the ledger, ensuring that transaction records are transparent and safe. Regulators can easily track transactions on the chain and quickly locate high-risk capital flows.

In terms of securities issuance transactions, the traditional stock issuance process is long, costly and complicated. Blockchain technology can weaken the role of underwriting institutions and help all parties establish a fast and accurate information exchange and sharing channel. The issuer can handle the issuance on its own through smart contracts. , regulatory authorities conduct unified review and verification, and investors can also bypass intermediaries for direct operations.

In terms of digital bills and supply chain finance, blockchain technology can effectively solve the financing difficulties of small and medium-sized enterprises. It is difficult for current supply chain finance to benefit small and medium-sized enterprises in the upper reaches of the industrial chain, because they often do not have direct trade relations with core enterprises, and it is difficult for financial institutions to evaluate their credit qualifications. Based on blockchain technology, we can establish a consortium chain network covering core enterprises, upstream and downstream suppliers, financial institutions, etc. The core enterprises issue accounts receivable vouchers to their suppliers. After the bills are digitized and uploaded to the chain, they can be uploaded to the supplier Transfer between them, each level of supplier can realize the corresponding amount of financing with the digital bill certificate.

Give me an example.

The China Enterprise Cloud Chain, jointly launched by ICBC, Postal Savings Bank of China, 11 central enterprises, etc., has covered 48,000 companies since its establishment in 2017, with the amount of rights confirmed on the chain reaching 100 billion yuan, and factoring financing of 57 billion yuan. , cumulative transactions reached 300 billion yuan. After receiving the loan application, financial institutions can verify the authenticity of the contract on the chain and whether the contract has been verified multiple times (multiple loans); the smart contract automatically clears and settles, reducing costs and increasing efficiency; at the same time, the accounts payable of core enterprises can have The corresponding vouchers will be split by the first-level suppliers and handed over to the second- and third-level suppliers in the chain to help them with financing; core enterprises can also use this to understand whether the entire chain is operating normally and avoid emergencies. Redemption pressure.

Blockchain technology will greatly optimize the existing use of big data and play a huge role in data circulation and sharing

The aforementioned areas are areas that we are relatively familiar with. As more new technologies develop, blockchain may be able to be combined with them and play a role in unexpected cross-fields and new scenarios that are currently unforeseen.

In the future, the Internet, artificial intelligence, and the Internet of Things will generate massive amounts of data. The existing centralized data storage (computing model) will face huge challenges. Edge storage (computing) based on blockchain technology is expected to become a future solution. Furthermore, the non-tampering and traceability mechanism of blockchain ensures the authenticity and high quality of data, which has become a majorThe basis for all data usage such as data, deep learning, and artificial intelligence.

Finally, blockchain can realize multi-party collaborative data calculations while protecting data privacy, and is expected to solve the problems of "data monopoly" and "data islands" and realize the value of data circulation.

In response to the current blockchain development stage, in order to meet the blockchain development and use needs of general business users, many traditional cloud service providers have begun to deploy their own BaaS ("Blockchain as a Service") solutions. The combination of blockchain and cloud computing will effectively reduce enterprise blockchain deployment costs and promote the implementation of blockchain usage scenarios. In the future, blockchain technology will also play an important role in many fields such as charity, insurance, energy, logistics, and the Internet of Things.

During this trial process from traditional technology to blockchain, we found that when certain scenarios have stronger demands for traceability, tamper-proofing, and decentralization, they also have problems with the weaknesses of blockchain (such as performance). , the requirements are not high, and this field is quite suitable for combining blockchain.

At the same time, in the process of blockchain evolution, it has also developed from a highly decentralized public chain accessible to everyone to a consortium chain with different permissions and maintained by multiple centers. Balances the advantages and disadvantages of the two systems.

Typical examples of alliance chains include: FISCO BCOS jointly developed by WeBank and the Golden Alliance Open Source Working Group, Fabric, a major contribution from IBM, and Ant Alliance Chain led by Ant Blockchain, etc.

These trustless systems represent more secure data authentication and storage mechanisms, where data is effectively authenticated and protected. Businesses or individuals can exchange or enter into contracts digitally, where these contracts are embedded in code and stored in transparent, shared databases where they cannot be deleted, tampered with, or revised.

It is boldly predicted that in the future, contracts, audits, tasks, and payments will all be digitized with unique and secure signatures. Digital signatures will be permanently identified, authenticated, legalized, and stored, and cannot be tampered with. There is no need for an intermediary to guarantee each of your transactions. You can conduct transactions without knowing the basic information of the other party. While improving information security, it effectively reduces transaction costs and improves transaction efficiency.

Generally speaking, there has been a lot of progress in the implementation of blockchain compared to two years ago.

Many improvements are at the bottom of the system, and users cannot directly see that blockchain is used, but they have actually benefited from it; some applications are still in pilot mode, and users have not yet been able to experience it. In the future, blockchain is expected to be used on a large scale and become one of the Internet infrastructure.

I hope that after reading this, you have a general understanding of what blockchain is and what blockchain can do.

Related Q&A: What is blockchain

Blockchain is actually equivalent to a disintermediated database, which is composed of a series of data blocks. Each of its data blocks contains information about a Bitcoin network transaction, which is used to verify the validity of the information and generate the next block.

In a narrow sense, blockchain is a time-basedA chained data structure that combines data blocks in a sequential manner, and is cryptographically guaranteed to be a distributed ledger that cannot be tampered with or forged.

In a broad sense, blockchain is actually a distributed infrastructure and computing method, which is used to ensure the security of data transmission and access.

Blockchain infrastructure:

Blockchain is composed of six infrastructures: data layer, network layer, consensus layer, incentive layer, contract layer and usage layer.

F. What is blockchain? An easy-to-understand explanation and how to explain it

Blockchain is actually equivalent to a disintermediated database, which is composed of a series of data blocks. Each of its data blocks contains information about a Bitcoin network transaction, which is used to verify the validity of the information and generate the next block.

In a narrow sense, blockchain is a chain data structure that combines data blocks in a sequential manner in chronological order, and is cryptographically guaranteed to be inextricable. Tamper-proof and unforgeable distributed ledger.

In a broad sense, blockchain is actually a distributed infrastructure and computing method, which is used to ensure the security of data transmission and access.

Blockchain classification

Public

Public Block Chains (Public Block Chains) refer to: any individual or Any group can send transactions, and the transactions can be effectively confirmed by the blockchain, and anyone can participate in its consensus process. The public blockchain is the earliest blockchain and the most widely used blockchain. The virtual digital currencies of all major bitcoins series are based on the public blockchain. There is only one blockchain corresponding to this currency in the world. .

Consortium

Industry Block Chains (Consortium Block Chains): Multiple pre-selected nodes are designated within a certain group as bookkeepers, and each block is generated by all pre-selected nodes. Nodes jointly decide (pre-selected nodes participate in the consensus process), other access nodes can participate in transactions, but do not participate in the accounting process (it is essentially still managed accounting, but becomes distributed accounting, how many pre-selected nodes, how to decide each The bookkeeper of the block becomes the main risk point of the blockchain), and anyone else can conduct limited queries through the open API of the blockchain.

Private

Private Block Chains: Only use the general ledger technology of the blockchain for accounting. It can be a company or an individual, and it can be used exclusively. The write permission of the blockchain is not much different from other distributed storage solutions. (Dec2015) Conservative giants (traditional finance) all want to experiment with private blockchains, while public chain applications such as Bitcoin have been industrialized, and private chain application products are still being explored.

G. How to explain blockchain in a popular way

Blockchain isIt is a decentralized distributed ledger database. The advantage of this distributed ledger is that buyers and sellers can trade directly without any intermediary. Everyone has a backup, even if your copy is lost, it will not be affected.

(7) Explanation of traceability of blockchain transactions Extended reading:

Blockchain application fields

1. Finance Field

Blockchain has potentially huge application value in financial fields such as international exchange, letters of credit, equity registration and stock exchanges. The application of blockchain technology in the financial industry can eliminate the need for third-party intermediaries and achieve direct point-to-point connection, thereby greatly reducing costs and quickly completing transaction payments.

2. Internet of Things and Logistics Fields

Blockchain can also be naturally combined in the Internet of Things and logistics fields. Through blockchain, logistics costs can be reduced, the production and delivery process of items can be traced, and the efficiency of supply chain management can be improved. This field is considered a promising application direction of blockchain.

3. Public welfare field

The data stored on the blockchain is highly reliable and cannot be tampered with, so it is naturally suitable for use in social welfare scenarios. Relevant information in the public welfare process, such as donation projects, fundraising details, fund flows, recipient feedback, etc., can be stored on the blockchain and transparently and publicly disclosed conditionally to facilitate social supervision.

4. Insurance field

In terms of insurance claims, insurance institutions are responsible for fund collection, investment, and claims settlement, and often have high management and operating costs. Through the application of smart contracts, there is no need for the policy holder to apply or the insurance company to approve it. As long as the claim settlement conditions are triggered, the insurance policy can automatically settle claims.

H. Briefly explain what blockchain is

Blockchain is a term in the field of information technology. In essence, it is a shared database, and the data or information stored in it has the characteristics of "unforgeable", "full traces left", "traceable", "open and transparent" and "collectively maintained". Based on these characteristics, blockchain technology has laid a solid foundation of "trust" and created a reliable "cooperation" mechanism, which has broad application prospects.

On January 10, 2019, the Cyberspace Administration of China issued the "Blockchain Information Service Management Regulations". On October 24, 2019, during the 18th collective study session of the Political Bureau of the CPC Central Committee, General Secretary Xi Jinping emphasized that “blockchain should be used as an important breakthrough for independent innovation of core technologies” and “accelerate the development of blockchain technology and industrial innovation.” . "Blockchain" has entered the public eye and become the focus of society.

On December 2, 2019, the word was selected into the top ten buzzwords of 2019 by "Biwenqiezi".

(8)Explanation of traceability of blockchain transactions Extended reading:

Blockchain financial applications:

2016 Since then, major financial giants have also taken notice and started toExpand blockchain innovation projects and explore the possibility of applying blockchain technology in various financial scenarios. In particular, Puyin Group took the lead in pioneering the “blockchain+” standard digital currency.

The standard digital currency is an asset that has been identified, evaluated, confirmed, insured, etc. by a third-party organization and written into the blockchain through rigorous digital algorithms to form a standard correspondence between the asset and the digital currency. relationship, called a standard digital currency.

In order to realize the great leap forward development of blockchain finance, in order to promote the new development of China's economy, accelerate the circulation of global assets, and realize the dream of rejuvenation that generations of people have been striving for, Puyin Group will Puyin Blockchain Finance Guiyang Strategy Release Ceremony was held in Guizhou on the 9th;

At the meeting, the digital circulation of assets through blockchain, the blockchain financial transaction model, and the relationship between blockchain services and blockchain services will be discussed. The application of social public industries will be discussed. This conference will mark the beginning of the application of blockchain finance and the transformation and development of a new financial ecosystem.

I. What does blockchain mean?

J. The most straightforward explanation of blockchain

In recent years, The word "blockchain" has become a hot topic, and news media are reporting on it. However, everyone's understanding of blockchain may still be in the foggy stage. Today we will unveil its mystery.

In fact, the essence of blockchain is very simple and can be explained in one sentence: decentralized distributed database.

The main function of the blockchain is to store information. Anyone can write information and read it at the same time, so it is a public database.

Characteristics of blockchain

Distributed database technology has long existed in the market, but the difference is that although blockchain is also a distributed database , but it has no administrator and is completely decentralized.

Decentralization is a disruptive feature of blockchain technology. It does not require a centralized agent and realizes a direct point-to-point interaction, enabling high-efficiency, large-scale, and information interaction without a centralized agent. way becomes reality.

However, without an administrator, everyone can write data into it. How can we ensure that the data is trustworthy? What should I do if I am changed by a bad person? The designers have already thought of this, which proves that blockchain is a truly epoch-making product.

Block

The 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:

Block header (Head): records the characteristic value of the current block
Block body (Body): actual Data
The block header contains multiple characteristic values ​​of the current block.

Generation time
The hash of the actual data (i.e. block body)
The hash of the previous block
...
Each node in the system has the latest Complete database copy, modifying the database of a single node is invalid, because the system will automatically compare and consider the same data record that appears the most times to be true. At the same time, every step of the data record will be retained on the blockchain, and the information at each step can be traced.

Here, you need to understand what a hash is, which is necessary to understand the blockchain.

The so-called "hash" 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 (hexadecimal), which is 256 bits when converted to binary, 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 approximately considered 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.

The immutability of hashes

Blocks and hashes have a one-to-one correspondence, and the hash of each block is for the "block header" (Head) computational. 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 includes the block header and not the block body. In other words, the hash is uniquely determined by the block header.

As mentioned earlier, 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 is of great significance to the 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 . For reasons to be mentioned later, hash calculation is very time-consuming.Modifying multiple blocks is almost impossible 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.