区块链中存储的数据类型有哪些,区块链中存储的数据类型有

近年来，区块链技术已经发展成为一种可以安全存储和分发数据的先进技术，它可以更有效地解决信息存储、交易安全和数据完整性等问题。那么，区块链中存储的数据类型有哪些呢？今天，我们就来聊聊区块链中存储的三种数据类型：交易数据、智能合约数据和元数据。

交易数据是区块链中最基本的数据类型，它是指由参与者之间进行货币交易或其他类型交易时产生的数据。交易数据是区块链上最常见的数据类型，它可以用来记录参与者之间的资金流动。与传统金融系统不同，区块链的交易数据是通过加密技术安全存储的，因此可以有效防止篡改和欺诈行为。

智能合约数据是指通过区块链技术来实现的一种特殊的程序，它可以根据参与者之间约定的条件自动执行特定的操作，从而达到实现自动化交易的目的。智能合约数据可以替代传统的合同，它可以在不受任何人控制的情况下，通过程序自动执行参与者之间的约定。智能合约数据可以有效地减少交易成本，提高交易效率，从而为参与者带来更多的便利。

元数据是指用于描述区块链中存储的其他数据的数据，它可以用来描述某个区块的基本信息，如区块的哈希值、时间戳、高度等。元数据也可以用来描述某个交易的基本信息，如交易的哈希值、发送者和接收者的地址等。元数据可以有效地帮助参与者查找和管理区块链上的数据，从而提高区块链的使用效率。

以上就是区块链中存储的三种数据类型：交易数据、智能合约数据和元数据。它们都是由区块链技术安全存储的，可以有效提高信息存储、交易安全和数据完整性等方面的效率。

⑴ Classification of blockchains

Currently blockchains are divided into three categories, among which hybrid blockchains and private blockchains can be regarded as: generalized private chains, public Blockchain public blockchain. This means that any individual or group in the world can send transactions, the transactions can be effectively confirmed by the blockchain, and anyone can participate in its consensus process. Public blockchain is currently the earliest blockchain and the most widely used blockchain. Each virtual digital currency of the Bitcoin series is based on a public blockchain, and there is only one blockchain in the world corresponding to this currency.
Extended information
1. Industrial blockchain industry blockchains: multiple pre-selected nodes in the group are designated as bookkeepers, and the generation of each block is jointly decided by all pre-selected nodes (pre-selected nodes participate in the consensus process), others Access nodes can participate in transactions but do not interfere with the accounting process (essentially, it is managed bookkeeping, but it becomes distributed bookkeeping). How many pre-selected nodes and how to determine the bookkeeper for each block become the main risk points of the blockchain ), anyone else can make limited queries through the blockchain’s open API. Private Blockchain Private Blockchain ((privateblockchains)): Only the general ledger technology of the blockchain is used for accounting. It can be a blockchain with exclusive written permission from a company or individual. This chain is not much different from other distributed storage solutions. At present (December 2015), conservative giants (traditional finance) want to try private blockchains, while the applications of public chains, such as Bitcoin, have been industrialized, and the application products of private chains are still being explored. Blockchain is a new application model of computer technologies such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithms. Blockchain is an important concept of Bitcoin. Essentially, it is a decentralized database.
2. At the same time, as the underlying technology of Bitcoin, it is a series of data blocks associated with encryption methods. Each data block contains a batch of Bitcoin network transaction information, verify the validity of its information (anti-counterfeiting) and generate the next block. In fact, the word blockchain does not appear in the original English Bitcoin white paper, but appears in blockchain. In the earliest Bitcoin white paper, blockchain was translated as blockchain. This is the time when the Chinese word "blockchain" first appeared. The Cyberspace Administration of China issued the "Blockchain Information Service Management Regulations" on January 10, 2019, which came into effect on February 15, 2019. In a narrow sense, a blockchain is a chained data structure that combines data blocks in chronological order, and a tamper-proof and forgery-proof distributed ledger guaranteed by cryptography. Broadly speaking, blockchain technology is a new distributed infrastructure and computing method that uses blockchain data structures to verify and store data, distributed node consensus algorithms to generate and update data, and cryptography to Ensure the security of data transmission and access, using smart contracts composed of automated script code to program and operate data.

⑵ What 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 try to translate "what is blockchain" 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 outcome?

At this time, the "consensus mechanism" in the definition of blockchain comes into play. The consensus mechanism mainly "stipulates" the following things: who will handle a data request when it is received (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 algorithmAny type of data can be quickly converted into a hash value. 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 blockchain first used, and 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".

Some people are not satisfied with the "Old Testament"In the world depicted, new sects were formed, doctrines were written into white papers, and stories of their faith were told 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 still leads the entire digital currency market with a market share of 66%, and the recent price has 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 USDT and Libra 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 greatly 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 openness, transparency, traceability, andFeatures such as non-tamperability enable transparent use, precise allocation 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 full life cycle management of 100 million eIDs, effectively alleviating 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 complex. 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., functioning in unexpected intersections and new scenarios that are not yet foreseeable.

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 becomes the basis for the use of all data such as big 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 to see you here, alreadyGet a general understanding of what blockchain is and what it 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 chain data structure that combines data blocks in a sequential manner in chronological order, and is cryptographically guaranteed to be non-tamperable and non-forgeable. 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 infrastructure:

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

⑶ What is the meaning of blockchain

Blockchain is a shared database. Blockchain is a combination of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. New application models.

Blockchain does not belong to any industry. Blockchain is a new application model of computer technologies such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm. In a narrow sense, blockchain is a chained data structure that combines data blocks in a sequential manner in chronological order, and is a cryptographically guaranteed distributed ledger that cannot be tampered with or forged.

Features

Decentralization. Blockchain technology does not rely on additional third-party management agencies or hardware facilities, and there is no central control. In addition to the self-contained blockchain itself, each node realizes self-verification, transmission and management of information through distributed accounting and storage. Decentralization is the most prominent and essential feature of blockchain.

Openness. The foundation of blockchain technology is open source. In addition to the private information of the transaction parties being encrypted, the data of the blockchain is open to everyone. Anyone can query the blockchain data and develop related applications through the public interface. Therefore, the entire System information is highly transparent.

⑷ In the blockchain, in what form the recorded data is stored

Encrypted code. A new block is generated every few minutes, which stores different information composed of different passwords (double keys).

⑸ What are the three sets of metadata contained in the block header in blockchain technology

1. The hash value of the previous block. Used for pre-index blocks
2. Mining difficulty, random value (for proof of work calculation), timestamp
3. Merkel tree, which can summarize and quickly summarize the verification blocks The root data of all transaction data.

⑹ What exactly is the blockchain?

What exactly is the blockchain? Essentially, blockchain is a distributed, decentralized network database system that allows data storage and updating.New, maintenance, operations become 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 read 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.

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 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, the consensus mechanism corresponds to the data processing and update stage, cryptography corresponds to data security, and smart contracts correspond to data operational issues.

⑺ How to explain blockchain in a popular way

Blockchain 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) Extended reading on the types of data stored in the blockchain:

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.