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『一』 What is the popular explanation of blockchain? You must know these five major application scenarios of blockchain!

Recently, blockchain has become popular overnight, and everyone around is discussing blockchain.

So, is the blockchain the same as Bitcoin?

In fact, Bitcoin and blockchain are not the same thing.

Blockchain is the underlying technology of Bitcoin, but the first usage scenario after the birth of blockchain is Bitcoin.

Bitcoin is just a string of data in a computer. Compared with paper currency, it is also called a "virtual currency". To put it simply, you can understand that Bitcoin is just a string of numbers with cash value, similar to Q coins. In other words, Bitcoin has no actual value. Its current value is supported by the faith of currency speculators. If the faith is gone, the value of Bitcoin will collapse.

What is blockchain? What are the characteristics of blockchain technology?

Let’s first take a look, why is blockchain called blockchain?

Data is stored piece by piece, and the data stored piece by piece is called a block. Different blocks are linked to the previous block, which is called a blockchain.

For example:

On a certain day of a certain year, Lao Wang lent Xiao Wang 10,000 yuan. Lao Wang told everyone around him the news , the transfer records were posted on WeChat Moments, and everyone helped them testify to the existence of this transaction.

Lao Wang and Xiao Wang are two nodes. These two nodes generate transaction time, location, person and other information, and they are packaged to form a "block". Lao Wang’s friends are also nodes. These nodes jointly record the transaction status and details (blocks) of the two nodes Lao Wang and Xiao Wang. These blocks are connected to form a blockchain.

Fundamentally, blockchain is a distributed ledger database.

What does distributed ledger mean?

Let’s take a look at the traditional accounting method.

The traditional accounting method is a centralized accounting method. For example, if Lao Wang lent 10,000 yuan to Xiao Wang, if Lao Wang did not tell the world about this money, then this amount would Only Lao Wang knows about the money transactions, Xiao Wang knows, God knows, and Earth knows. This accounting method is a centralized accounting method. This method has a very fatal shortcoming: what should I do if the other party does not acknowledge the account? In fact, in real life, in spontaneous private lending relationships, there is no evidence when the lending relationship occurs, resulting in many cases where the other party does not acknowledge the debt afterwards.

Lao Wang adopted a bookkeeping method that was known to the world from the beginning, to preventTo avoid future troubles, this method is a blockchain distributed ledger, which has the characteristics of decentralization. Everyone is the center and everyone can testify to the existence of this transaction.

In addition to the characteristics of decentralization, blockchain also has the characteristics of being immutable. In the blockchain, if the data in any one block changes, even if it only changes a punctuation mark, it will become invalid and needs to be recalculated. Therefore, in the blockchain technology, once a piece of data changes, the cost will be Very big. Unless all nodes in this blockchain have 51% control. Therefore, the blockchain system will be stable and secure.

It’s still Lao Wang and Xiao Wang. If Xiao Wang wants to default on his debt, he can’t tamper with it unless he bribes everyone in the world who knows about the transaction.

Blockchain is also open and transparent.

In blockchain technology, all data is public, which is still the case of Lao Wang and Xiao Wang.

If Xiao Wang does not accept the money, once this news is released, then Xiao Wang’s reputation will be ruined. He can only pay back the money to release new news and wash out the money. Clear your own identity.

Some people say that if the blockchain is so powerful, will my identity information be revealed and there will be no privacy? In fact, the blockchain has the characteristics of anonymity, which protects our privacy very well. Unless required by legal regulations, technically speaking, the identity of each block node does not need to be disclosed or verified, and can be done anonymously.

What are the applications of blockchain?

The origin of blockchain is to solve the problem of trust, and one of the most successful applications of blockchain is digital currency. Bitcoin is arguably the most successful application of blockchain so far.

In addition to digital currency, the future applications of Bitcoin are still very wide, and blockchain technology has been widely used in different industries. Such as product traceability, copyright protection and transactions, payment and settlement, Internet of Things, digital marketing, medical care, etc., promoting different industries to quickly enter the "blockchain+" era.

1. Payment and clearing

The role of the intermediary bank can be abandoned, point-to-point payment can be realized, intermediary fees can be reduced, and fund utilization can be accelerated.

2. Product traceability

For example, if we buy a piece of clothing on a certain website, we can see the past and present life of this piece of clothing.

3. Securities trading

Traditional securities trading requires the coordination of four major institutions, which is inefficient and costly. Blockchain technology can independently complete one-stop services.

4. Supply chain

Introducing blockchain technology into the supply chain system, information can be synchronized within the system and all aspects can be monitored.Control every step to better complete division of labor and collaboration, and facilitate accountability afterwards.

5. Intellectual property rights

With copyright on the chain, our photographic works, musical works, literary works, etc. will become our information, and the ownership of the information will be confirmed and become our property.

『二』 What are the core blockchain technologies of blockchain technology?

What is the hottest topic on the Internet right now? You don’t need to tell me what the editor is saying, that is Blockchain technology, but many friends have only heard of this technology and do not have much in-depth understanding of it. So what are the blockchain technologies? Below we will bring you an introduction to the core technology of blockchain for your reference.
What are the core elements of blockchain technology?
Blockchain technology can be a public ledger (visible by anyone) or a permissioned network (visible only by those authorized), which solves supply chain challenges , because it is an immutable record that is shared among network participants and updated in real time.
Blockchain technology----data layer: designing the data structure of the ledger
Core technology 1. Block + chain:
Technically speaking, block is a data structure that records transactions. Reflects the flow of funds for a transaction. The blocks of transactions that have been reached in the system are connected together to form a main chain, and all nodes participating in the calculation record the main chain or part of the main chain.
Each block consists of a block header and a block body. The block body is only responsible for recording all transaction information in the previous period, mainly including the number of transactions and transaction details; the block header encapsulates the current version number, previous A block address, timestamp (recording the time when the block was generated, accurate to seconds), random number (recording the value of decrypting the answer to the math question related to the block), target hash value of the current block, and Merkle number Root value and other information. From a structural point of view, most functions of the blockchain are implemented by the block header.
Core technology 2. Hash function:
The hash function can convert data of any length into a set of fixed-length codes through the Hash algorithm. The principle is based on a cryptographic one-way hash function. This kind of function is easy to verify, but difficult to crack. Usually, the industry uses y=hash(x) to represent it. This hash function implements operations on x to calculate a hash value y.
Commonly used hash algorithms include MD5, SHA-1, SHA-256, SHA-384 and SHA-512, etc. Taking the SHA256 algorithm as an example, inputting any string of data into SHA256 will result in a 256-bit Hash value (hash value). Its characteristics: the same data input will get the same result. As long as the input data changes slightly (for example, a 1 becomes a 0), a completely different result will be obtained, and the result cannot be predicted in advance. Forward calculation (calculating the corresponding Hash value from the data) is very easy. Reverse calculation (cracking) is extremely difficult, inIt is considered impossible under current technological conditions.
Core technology 3. Merkle tree:
Merkle tree is a hash binary tree, which can be used to quickly verify the integrity of large-scale data. In the blockchain network, the Merkle tree is used to summarize all transaction information in a block, and ultimately generates a unified hash value of all transaction information in the block. Any change in transaction information in the block will cause Merkle tree changes.
Core technology 4. Asymmetric encryption algorithm:
Asymmetric encryption algorithm is a key secret method that requires two keys: public key and private key. The public key and the private key are a pair. If the public key is used to encrypt the data, only the corresponding private key can be used to decrypt it, thereby obtaining the corresponding data value; if the private key is used to sign the data, then only the corresponding public key can be used to sign the data. In order to verify the signature, the sender of the verification information is the holder of the private key.
Because encryption and decryption use two different keys, this algorithm is called an asymmetric encryption algorithm, while symmetric encryption uses the same key in the encryption and decryption processes.
Blockchain technology----network layer: realize the decentralization of accounting nodes
Core technology 5. P2P network:
P2P network (peer-to-peer network), also known as point-to-point technology, is no Central server, Internet system that relies on user groups to exchange information. Unlike a centralized network system with a central server, each client in a peer-to-peer network acts as both a node and a server. Domestic Xunlei software uses P2P technology. The P2P network has the characteristics of decentralization and robustness.
Blockchain technology----Consensus layer: allocate the task load of accounting nodes
Core technology 6. Consensus mechanism:
Consensus mechanism is how to reach consensus among all accounting nodes to identify The validity of a record is both a means of identification and a means of preventing tampering. There are currently four main types of consensus mechanisms: PoW, PoS, DPoS and distributed consensus algorithms.
PoW (Proof of Work, proof of work): PoW mechanism, which is like Bitcoin’s mining mechanism, miners package existing transactions that have not been recorded by the network into a block, and then continue to traverse and try to find a random number , so that the hash value of the new block plus the random number meets certain difficulty conditions. Finding a random number that meets the conditions is equivalent to determining the latest block of the blockchain, and is also equivalent to obtaining the current round of accounting rights of the blockchain. Miners broadcast blocks that meet the mining difficulty conditions in the Yuanfu network. After verifying that the block meets the mining difficulty conditions and that the transaction data in the block meets the protocol specifications, other nodes in the entire network will each Blocks are linked to their own version of the blockchain, thereby forming a network-wide consensus on the current network state.
PoS (ProofofStake, Proof of Stake): PoS mechanism, which requires nodes to provide proof of a certain number of tokens to obtain the right to compete for blockchain accountingDistributed consensus mechanism. If you rely solely on the token balance to determine the bookkeeper, you will inevitably make the rich win, which will lead to the centralization of bookkeeping rights and reduce the fairness of the consensus. Therefore, different PoS mechanisms use different methods to increase the amount of money based on the proof of equity. The randomness of accounting rights avoids centralization. For example, in the PeerCoin PoS mechanism, the Bitcoin with the longest chain age has a greater chance of obtaining accounting rights. NXT and Blackcoin use a formula to predict the next accounting node. The more tokens you own, the greater the probability of being selected as an accounting node. In the future, Ethereum will also switch from the current PoW mechanism to a PoS mechanism. Judging from the information currently available, Ethereum's PoS mechanism will use nodes to place bets on the next block. The winner of the bet will receive an additional Ethereum currency award. Those who do not win will be deducted Ether coins to reach consensus on the next block.
DPoS (DelegatedProof-Of-Stake, share authorization certificate): DPoS is easy to understand and is similar to the modern corporate board of directors system. The DPoS mechanism adopted by BitShares is that shareholders vote to select a certain number of witnesses. Each witness has two seconds of authority to generate blocks in order. If the witness cannot generate a block within the given time slice, The block generation authority is given to the witness corresponding to the next time slice. Shareholders can replace these witnesses at any time by voting. This design of DPoS makes the generation of blocks faster and more energy-saving.
Distributed Consistency Algorithm: Distributed Consistency Algorithm is based on traditional distributed consistency technology. Among them are Byzantine fault-tolerant algorithms that solve the Byzantine Generals problem, such as PBFT (Byzantine fault-tolerant algorithm). In addition, distributed consensus algorithms (Pasox, Raft) that solve non-Byzantine problems are not explained in this article. This type of algorithm is currently a commonly used consensus mechanism in alliance chain and private chain scenarios.
Taken together, POW is suitable for public chains. If you build a private chain, it is more suitable to use POS because there is no trust problem in verification nodes; and because there are untrustworthy local nodes in the alliance chain, it is more suitable to use DPOS.
Blockchain technology----Incentive layer: Develop a "salary system" for accounting nodes
Core technology 7. Issuance mechanism and incentive mechanism:
Take Bitcoin as an example. Bitcoins are initially rewarded by the system to miners who create new blocks, and this reward is halved approximately every four years. At the beginning, miners were rewarded with 50 Bitcoins for each new block recorded, and this reward is halved approximately every four years. By analogy, by around AD 2140, newly created blocks will no longer receive rewards from the system. By then, the total number of Bitcoins will be approximately 21 million. This is the total number of Bitcoins, so it will not increase indefinitely.
Another source of incentives is transaction fees. When there are no system rewards for newly created blocks, the miners' income will change from system rewards to transaction fees. For example, when you transfer, you can specify 1% of it as a handling fee to be paid to the miner who records the block. If aIf the output value of a transaction is less than the input value, the difference is the transaction fee, which will be added to the incentive of the block. As long as a given amount of electronic currency has entered circulation, the incentive mechanism can gradually be converted to rely entirely on transaction fees, so there is no need to issue new currency.
Blockchain technology----Contract layer: giving the ledger programmable features
Core technology 8. Smart contract:
Smart contract is a set of programmed rules and logic that respond to scenarios. Implemented by decentralized, trusted shared script code deployed on the blockchain. Normally, after the smart contract is signed by all parties, it is attached to the blockchain data in the form of program code, and is recorded in a specific block of the blockchain after being propagated through the P2P network and verified by nodes. Smart contracts encapsulate a number of predefined states and transition rules, scenarios that trigger contract execution, response actions under specific scenarios, etc. The blockchain can monitor the status of smart contracts in real time, and activate and execute the contract by checking external data sources and confirming that specific trigger conditions are met.
The above is what blockchain technologies the editor has brought to you? All content of the introduction to the core technology of blockchain.

『三』 What is blockchain

What is blockchain? What changes will it bring to your future life?

Blockchain is a new application model of computer technologies such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm.

Blockchain is an important concept of Bitcoin. It is essentially a decentralized database. At the same time, as the underlying technology of Bitcoin, it is a series of cryptographic methods related to each other. Each data block generated contains a batch of Bitcoin network transaction information, which is used to verify the validity of the information (anti-counterfeiting) and generate the next block.

In fact, the original English version of the Bitcoin white paper does not appear in the word blockchain, but uses chain of blocks. In the earliest Chinese translation of the Bitcoin white paper, chain of blocks was translated into blockchain. This is the earliest time when the Chinese word "blockchain" appeared.

The Cyberspace Administration of China issued the "Blockchain Information Service Management Regulations" on January 10, 2019, which will come into effect on February 15, 2019.

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-transformable. Fake distributed ledger.

So in conclusion, this is undoubtedly a new technology that changes life. In the future, the production activities of the entire society will be carried out with blockchain as the underlying logic. Many things We all have it at our fingertips, and with the integration of artificial intelligence and big data, we can easily handle things that seem complicated now, such as some securities market transactions.Easy and intelligent matching of financial management activities.

To put it simply, blockchain is a network computing center that integrates people, property, machines, and goods, and packages them into a whole; putting it on an infrastructure to run.

『四』 First introduction to Hyperledger Fabric

Fabric is a consortium chain. Peer represents a series of organizations. Peers are the basis of the entire blockchain network because it is the basis of ledgers and smart contracts. carrier. Through smart contracts, the ledger records the entire transaction process in an immutable way.

For companies that cannot, there are different businesses, and different businesses are associated with different companies. Multiple alliance chains need to be created, so multiple channels need to be created. How many channels are there? A private network established between specific members for the purpose of confidential transactions. A peer can join multiple channels. Each channel maintains its own ledger. The ledgers are isolated from each other. Each channel can maintain one or more ledgers. . Therefore, in order to meet complex transaction requirements, different smart contracts can be installed on each peer. When the peer transaction is completed, an event will be sent to notify the Client. There is also a Local MSP (Member Service Provider) service on the peer, which provides functions such as identity authentication and cryptographic signatures.

WorldState maintains the current information of the current ledger in the form of key-value.

Smart Contract is the core of the blockchain, defining business specifications between different organizations, creating transactions and recording them in the ledger. Multiple smart contracts can be packaged into one chaincode. Smart contracts can only be used by applications after the chaincode is deployed.

Unlike ordinary chain codes that run in an independent container, system chain codes run on the peer process and implement some system behaviors.

In order to optimize network performance, improve security and scalability, Fabric divides each transaction into Endorsing Peer, Ording-Service and Committting Peer three parts, which requires a secure, trusted and scalable data transmission protocol - Gossip Protocol. The Gossip transmission protocol disseminates information into the network in a random manner and mainly performs three functions:

『Wu』Using the AWS Blockchain template to build Hyperledger Fabric

AWS Blockchain The template claims to be able to create and deploy a blockchain network in just a few minutes.

Two types of blockchain networks can be built using AWS Blockchain Templates:

For specific construction steps, please refer to the AWS Blockchain Templates Developer Guide, which has details about building Ethereum. Steps, the "prerequisites" setting items in the document are used to build the Ethereum network and are not applicable to the Fabric network, so here we talk about building Fabric of Hyperledger.

Before using the template to quickly create a stack, be sure to set the relevant content in advance:

Note:

The above five prerequisites are set correctly. We can use the blockchain template to create the Fabric network. Let’s talk about the two more difficult configurations with red boxes:

Setting steps:

Click " Review Policy", set the name (myFabricPolicy) and description (...) of this permission policy file, and finally click "Create Policy":

The settings are as follows:

AWS Console— —Services—VPC—In the VPC Control PanelClick the blue button "Launch VPC Wizard" and select a VPC with a single public subnet:

Set the VPC name and subnet name, and other values ​​are default values.

Click the launch link in the Hyperledger Fabric section of the AWS Blockchain Templates Developer Guide:

The setting reference is as follows:

After creation, drink a cup of coffee ☕️ and wait for a while. ..

Wait until the status is displayed as "CREATE_COMPLETE" and it will be OK. 🎉🎉🎉

『Lu』 Blockchain Alliance Chain (3) Understanding Fabric

Fabric is the core block launched by the Hyperledger Alliance Chain framework, which is suitable for building alliance chains within complex enterprises and between enterprises. According to the goals of the Hyperledger Alliance, Fabric is built as a modular basic alliance chain framework that supports pluggable components. ;

Unlike Ethereum-based Quorum, Fabric only considered inter-enterprise applications from the beginning. Its unique channel concept connects enterprises in different subnets according to different business purposes. Each subnet corresponds to a channel, and each channel has its own independent blockchain. Quorum obviously has only one public network (all enterprise nodes join it), and private business between enterprises is completed through Private Manager.

The simplest way to understand channel is to analogize it to a Topic provided by a message service. In fact, Fabic was first implemented based on Kafka's distributed message service.

In the Fabric network, an enterprise can have one or more nodes joining itThe entire alliance chain; an enterprise can join one or more Channels (subnets); a node can join one or more channels. Each channel forms a subnet, so Fabric is a network composed of subnets.

So how does Fabric implement the execution of smart contracts and complete business uploading (recording transaction results in the blockchain)?

Unlike other frameworks, Fabric divides the entire process into three stages:

Business endorsement stage: The endorsement node sent by the customer's request completes the business calculation through smart contracts (but does not update the status), and completes the endorsement; returns the endorsement result to the client.

Business sorting phase: The client sends the endorsement results to the ordering node (orderer) through the Channel. The ordering node completes the sorting of transactions, packages them into blocks, and finally distributes them to all connected The node of the channel.

Business verification and writing to the ledger stage: Through the Gossip network, all Channel nodes will receive the new block. The nodes will verify each transaction in the block to determine whether it is valid: valid will be followed by In the new world state, invalid ones will be marked as "invalid" and the world state will not be updated, but the entire block will be completely added to the ledger (including invalid transactions).

Based on the above description, Fabric nodes can actually be divided into , ordinary nodes and Order nodes:

Peer, ordinary nodes, complete endorsement (including execution of contracts only) and Verification.

orderer, sorting node, completes sorting.

The Fabric network that joins the orderer node can be described as follows:

Each Channel defines all nodes belonging to the channel, but it is not necessary that all nodes are connected to the Orderer Nodes (private data or transactions can be spread between nodes through gossip protocol communication).

In the blockchain, consensus is the basis of the blockchain. Different from the public chain, the consensus of the alliance chain requires that all transactions added to the ledger are deterministic and final, that is, there cannot be forks. The order between blocks isFor sure, there is only one chain. In Fabric, this objective requirement is realized by sorting. All transactions will be submitted to the orderer node to obtain a determined order, and finally packaged into blocks and entered into the ledger. Fabric supports the implementation of ordering services based on Raft starting from 1.4.1, which can be considered as the implementation of consensus based on Raft.

The RAFT-based sorting service has better distribution and simpler configuration than the early Kafka. It is a commonly used consensus algorithm in alliance chains. Quorum uses RAFT as the consensus by default. layer. Simply put, RAFT is a leader and follower model. All nodes joining the RAFT network have a leader at any time. Only this leader has the right to decide the order of transactions and package them into blocks. Other nodes can only submit transactions as followers. and sync block.

Based on the FAFT network, each enterprise can have one or more nodes participating in the Orderer. In Frabric, the network connection between enterprises can be changed into the following form:

Users of blockchain are called EOA (External of Account) in Ethereum, and the carrier of EOA is a wallet. Let's use this concept to see how Fabric implements users and initiates transactions. EOA in Fabric is a certificate (x.509) issued by the CA center. A Certificate represents an Identity (this is still very different from Ethereum. An EOA in Ethereum is actually a hash address). The channels that EOA can participate in And the authorized operations are determined by the MSP (Membership Service Provider) of the channel (as shown below).

Note: Certificate is a common method of verifying identity in cryptography; certificate contains personal information, public key and signature of the CA that issued the certificate. The verifier only needs to have the CA's certificate (including the CA's public key) to verify whether the signature is correct and whether the content of the certificate has been tampered with. Simply put, through CA and Certificate, we can obtain a verifiable identity and trust chain.

As shown in the picture above, Fabric Zhongtong uses Wallet as the carrier of EOA. A Wallet can contain multiple Identities (x.509 certificate). Identity verifies correctness through the chain of trust provided by the CA.

After verifying the identity, Fabric uses MSP to resolve in the blockchain network whether the identity represents a member of the organization and what role it has within the organization. For example, the channel will first verify whether the current user Identity is a valid identity, then check the enterprise and role it has through MSP, and finally determine whether the user has the right to perform operations.

It can be said that Fabric access control is completed through MSP. An MSP needs to be defined every time access control is required. For example, each channel defines an MSP, which specifies the access rights to resources within the channel range. MSP is an obscure concept in Fabric, and it is also the basis for providing secure access between enterprises.

As mentioned earlier, Fabric divides business processing and Internet access into three parts: endorsement, sorting, and adding to the ledger after verification.

Endorsement is the stage in which Fabric executes smart contracts. In Ethereum, smart contracts are executed in the EVM and are supported in multiple languages. In Fabric, smart contracts are called chaincode: A chaincode can be understood as a container for smart contracts, which can contain one or more smart contracts. It is not used for EVM. Chaincode is executed in JVM or NodeJS.

Client applications access the ledger through smart contracts. Each accessible smart contract is installed on a node accessible to the client and is defined in the channel. (Nodes with smart contracts are called endorsement nodes, nodes without smart contracts are called unsubmitted nodes, and submitting nodes only maintain ledgers)

The client application submits a transaction request, and the request reaches the endorsement node , the endorsement node will first verify the customer's signature to ensure that the customer's identity has the right to execute this transaction, then execute the smart contract (chaincode) mentioned in the transaction, and generate an endorsement response (or transaction proposal, trans-proposal). This endorsement response usually contains the world state's read set, write set, and the node's signature for this transaction. The main difference here from the Ethereum alliance chain is that the endorsement phase only simulates transactions and does not actually update the transaction results. The real update transaction is completed in the third phase.The endorsement node finally sends the generated endorsement response fanhui to the client, and the execution of the smart contract part ends.

Usually the execution of a transaction requires the signatures of multiple parties, so the client needs to send a transaction to multiple endorsement nodes, and the selection of these endorsement nodes needs to meet the requirements of the endorsement policy.

The following figure is a network diagram including customers, endorsement nodes, and submission nodes.

According to Fabric’s official reference document, the process of successful customer transactions can be described in the following figure.

As shown in the figure above, from 1 to 3, it is the endorsement stage, 4 is the sorting stage, and 4.1, 4, 2, 5 are the verification and submission stages. Refer to Frabic's node concept to learn more about the concept of transaction details.

Generally speaking, Fabric is more focused on inter-enterprise. Through the above, everyone can have a general understanding of the basic composition and concepts of Fabric. Fabric itself is not mysterious. It uses existing inter-enterprise technologies. For a better understanding, it is recommended to read Support for Distributed Messaging Systems and Enterprise Security Infrastructure (CA related). Compared with the Ethereum-based alliance chain implementation, Fabric's subnet concept is more adaptable to complex inter-enterprise applications, but its complex security considerations make operating costs very high. In addition, Fabric uses Certificate as user identity, which has great The limitations of Fabric will be changed in the new 2.0.

In the next article, we will take a look at Sawtooth, a blockchain framework provided by Inter.

Blockchain Alliance Chain (1) Understanding Ethereum

Blockchain Alliance Chain (2) Understanding Quotum

Blockchain Consortium Chain (3) Understanding Fabric

Consortium Chain of Blockchain (4) Understanding Sawtooth

『淒』 What exactly is blockchain and which blockchains have physical applications?

What is blockchain?

Official definition: Blockchain is a new application model of computer technology such as distributed data storage, point-to-point transmission consensus mechanism encryption algorithm, etc. The so-called consensus mechanism is a mathematical algorithm that establishes trust and obtains rights and interests between different nodes in the blockchain system.

Vernacular understanding: A block is to package all the data generated within a time period in chronological order. Generally, the length of a block is 10 minutes, which means that within 10Within minutes, all Internet data on the network is packed into a complete package. This complete data package is called a block. The blockchain links these data packages in order to form a structure and cryptographically It is guaranteed not to be tampered with or forged to form a distributed ledger, which is the blockchain.

It seems that everyone has a preliminary knowledge and understanding of the blockchain. So whether the blockchain has any practical application in daily life, the answer is yes, the current practical application There are mainly the following aspects. Of course, I may not know some of them. Friends are welcome to leave messages to add.

Financial Industry

Blockchain should be used the most in the financial industry.

For example, in May 2017, OMG (Omise Coin) announced that it would cooperate with Alipay to launch an electronic wallet, integrating the "Alipay" payment solution into its own payment service suite to help local electronics in Thailand. Business merchants accept online payment transactions from Chinese tourists.

Another example is PPT, which is a financial transaction system for bills based on blockchain.

Gaming

The gambling industry entered the blockchain probably last year. Why does gambling favor blockchain? Because blockchain provides a relatively fair betting system. Why? It is relatively fair. As can be seen from the previous introduction, the blockchain cannot be tampered with or forged.

For example, WICC (WikiChain) can realize rich application scenarios such as asset issuance, betting applications, copyright traceability, mutual insurance, decentralized exchanges, and cross-border settlement.

For example, the STX (King of Fighters Token) stox application is designed to provide the full functionality of a prediction market application without the need for any central server. Prediction markets require functions such as event planning, market production, providing information and analysis to traders, reporting event results, and of course collection and payment.

I believe that if the current lottery industry is built on the blockchain, people will become more and more enthusiastic about buying, because there are too many insider tips that make people give up.

Internet of Things

The Internet of Things still has many applications on the blockchain, because the traceability and immediacy of blocks are very suitable for this industry.

For example, DATA is the concept of the Internet of Things. It is a decentralized p2p network. Data sources can connect to any node in the entire network, then publish data, and the network will immediately send it to subscribers. Horizontal scalability is achieved through sharding pattern. This timeliness and accuracy are very important in IoT applications.

Game industry

For example, GTC (G coin) is a decentralized digital asset based on Ethereum erc20 issued by Game Global. G coin is committed to becoming a universal number in the global game industry. Monetary standards.

For example, MANA is a distributed shared virtual platform. On this platform, users can browse and discover content and connect with othersInteract with entities. Users can also claim ownership of virtual territories through a blockchain-based land ledger. The territory is demarcated by rectangular coordinates (x, y), and its owner can decide the content published on the territory, including static 3D scenes to interactive systems such as games.

There are many other industries. The emperor did not list them one by one, but listed a few representative ones. What is the purpose? It shows that the blockchain is definitely not just a currency transaction, it is a real implementation project, and it is a product of the changes of the times with real practical uses.

The development of human society is actually like the blockchain, it is irreversible and unstoppable. As far as I feel, the blockchain will enter thousands of households sooner or later. Regardless of whether it is bull or bear, hold it in your hands. Value coins and Flush have started quoting digital currencies, which shows that society is accepting it step by step. The power of social development cannot be blocked by any country or person.

『8』What is blockchain and how do ordinary people make money in blockchain?

The popularity of blockchain has caught the masses off guard. Nowadays, no one knows about blockchain, but many people do not have a clear understanding of the definition of blockchain.

So, what exactly is blockchain?

Regarding blockchain and Bitcoin, most people have this misunderstanding: Bitcoin is blockchain.

In fact, Bitcoin and blockchain are not the same thing. Blockchain is the underlying technology of Bitcoin, but the first usage scenario after the birth of blockchain is Bitcoin.

I will explain to you what Bitcoin is and what blockchain is. Please move your bench quickly!

What is Bitcoin?

Bitcoin is a digital currency, a peer-to-peer encrypted digital currency. It is not a tangible paper currency such as RMB or US dollars. It is generated by computers through specific mathematical calculations. Also stored in the computer.

Because Bitcoin is just a string of data in a computer, it is also called a "virtual currency" compared to paper currency. To put it simply, you can understand that Bitcoin is just a string of numbers with cash value, similar to Q coins. In other words, Bitcoin has no actual value. Its current value is supported by the faith of currency speculators. If the faith is gone, the value of Bitcoin will collapse.

Bitcoin is magical, what is its magic?

If you want to get Bitcoin, in addition to buying it, you can also mine it. The original Bitcoin is mined!

1) Mining

The first thing that comes to mind for many people is the image of a coal mine:

Mine, absenteeism, dust , black coal, large trucks.

Bitcoin mines are not like this. They only need electricity, network cables, and computers. However, mining this mine is a technical job, and it tests the performance of the computer's CPU and GPU.

2) Transaction

How does a Bitcoin transaction proceed?

Each user has a unique address, which is the Bitcoin "wallet". For every transaction, for example: A pays B a Bitcoin, a Weibo post will be posted publicly in the system saying: "I gave B a Bitcoin @B". These records will be kept as evidence at every terminal of the system. on the chain.

If A wants to go back on his word and tamper with Bitcoin’s transaction history, then every terminal record on the network must be modified. However, this is not easy, because only A whose computing power exceeds the sum of the computing power of all nodes in the system can tamper with transaction records. Obviously, this is unrealistic.

In the transaction process, Bitcoin uses a decentralized accounting method, which is also blockchain technology. Simply put, blockchain is a decentralized distributed ledger database.

What is blockchain?

The blockchain was created along with Bitcoin. During the formation of Bitcoin, blocks were storage units one by one, recording the communication information of each block node. Blocks are very similar to For database records, every time data is written, a block is created. With the expansion of information exchange, one block continues with another, and the result is called a blockchain.

Blockchain is a distributed ledger technology. Everyone participates in accounting, and everyone has a copy of the ledger information. This account book is not easy to forge and is traceable.

For example:

On a certain day of a certain year, Lao Wang lent Xiao Wang 10,000 yuan. Lao Wang told everyone around him the news , the transfer records were posted on WeChat Moments, and everyone helped them testify to the existence of this transaction.

Lao Wang and Xiao Wang are two nodes. These two nodes generate transaction time, location, person and other information, and they are packaged to form a "block". Lao Wang’s friends are also nodes. These nodes jointly record the transaction status and details (blocks) of the two nodes Lao Wang and Xiao Wang. These blocks are connected to form a chain, forming a decentralized database.

In the past, only both parties knew when Lao Wang and Xiao Wang borrowed money. This was the centralized accounting model. But now everyone knows it and records it in their own ledgers. This is the decentralized accounting model. model.

When one day, Xiao Wang regrets that he did not borrow the money, everyone around him will know their transaction information, so Xiao Wang will not be able to deny it. This is the blockchain Information sharing cannot be tampered withFeatures.

How do ordinary people make money by participating in the blockchain?

I have summarized several methods suitable for ordinary people to make money during the blockchain bonus period.

1. Direct investment in blockchain: buy coins or buy some blockchain stocks, but the currency circle is risky, so you must be cautious when buying, and there are many blockchain stocks now. However, there are risks in the stock market, so investment needs to be cautious.

2. Make blockchain self-media: run a WeChat public account or Toutiao account, write articles about blockchain and publish them on it. If you are good, you can also get some good profits.

3. Participate in technology development: In fact, it is very simple, it is to participate in the process of blockchain development. However, this method requires high technical threshold.

4. Blockchain training: Companies that can provide blockchain technology training or knowledge training.

That’s all the relevant knowledge about what blockchain is, I hope it can bring you some help.

『玖』 Blockchain - What is Blockchain? Jindian Bixin can understand Blockchain

Blockchain - What is Blockchain? Can Jindian Coin News understand the blockchain?

Block Pioneer animation video helps you understand what is blockchain, easy to understand

What is blockchain, does Maobei belong to blockchain?

Answer: Maobei does not belong to the blockchain, but only uses blockchain technology. The characteristic of the blockchain is that everything that happens will be recorded and cannot be deleted or changed.

Blockchain, what is a block

Comprehensive interpretation of blockchain

When talking about blockchain, people always compare it with Bitcoin. On October 31, 2008, a person named "Satoshi Nakamoto" sent an email to a cryptography email group, claiming, "I have been working on a new electronic cash system, which is completely peer-to-peer and does not require Any trusted third party.” He launched a new system using Bitcoin as the transaction currency.

What is blockchain technology? What is blockchain?

Blockchain is a distributed shared accounting technology. What it wants to do is to allow all parties involved to establish a trust relationship at the technical level.

Blockchain can be roughly divided into two levels. One is the underlying technology of the blockchain; the other is the upper-layer application of the blockchain, that is, transformation based on the blockchain, Optimize or innovate applications.

What is the core meaning of blockchain? Our understanding is that the core meaning of blockchain is to establish data credit among participants, and to create a single transaction under clear regulations through unilateral confrontation. The ecology of all aspects jointly guarantees complete opportunities. This is a system. This establishment can end the problems before the blockchain. Before the blockchain, it was impossible to achieve new sharing when data was shared, even if it was targeted. Just give you an interface, after the blockchain is created, the participants can realize the sharing of credit.

What are the underlying platforms of blockchain?

Answer: There are mainly the following categories:

1. Bitcoin. The earliest blockchain development was based on the Bitcoin blockchain network. Since Bitcoin is the most widely used and truly decentralized in the world, in terms of blockchain applications, Bitcoin is the most widely used blockchain in the world. A strong anchor with the greatest authority.

2. Ethereum. It can be said that apart from Bitcoin, Ethereum is currently the most eye-catching blockchain platform. Ethereum is a Turing-complete blockchain one-stop development platform that uses multiple programming languages ​​to implement protocols. It uses a client written in Go language as the default client (i.e., the method of interacting with the Ethereum network, and supports many other language client).

3. IBM HyperLedger. Also called fabric, its goal is to build a super ledger that is jointly maintained by the whole society. Fabric originated from IBM. Its original intention was to serve industrial production. IBM open sourced 44,000 lines of code, which is a great contribution and allows us to have The opportunity is so close to explore the principles of blockchain that are different from Bitcoin.

4. LISK. It is a new generation of blockchain platform that allows the development of JavaScript (Javascript technology again, engineers, take note) and distribution-based decentralized applications using an easy-to-use, full-featured ecological blockchain system.

5. Online recording blockchain platform. It is the research and development result of the underlying technology of the Wanglu blockchain and a basic platform capable of commercial delivery. In addition to serving the Wanglu public chain, the Wanglu blockchain platform is also the basic platform for Wanglu to create private chains and alliance chains for customers.

What is blockchain? What is blockchain for digital currencies?

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. Ledger. Broadly speaking, blockchain technology uses block chain data structures to verify and store data, uses distributed node consensus algorithms to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses automated scripts to A new distributed infrastructure and computing paradigm that uses smart contracts composed of code to program and manipulate data.
Nowadays, mainstream digital currencies are basically developed based on blockchain technology. Blockchain is the underlying technology of digital currency. The domestic tea-based digital currency Puyin was developed based on blockchain technology.

What is blockchain

The essence of blockchain is a decentralized accounting system, and Bitcoin is the currency that "exists in digital form" carried on this system. Blockchain is a system behind Bitcoin that consists of credit records and the settlement of credit records.

Blockchain is a new application model of computer technologies such as distributed data storage, point-to-point transmission, consensus mechanism, and encryption algorithm. The so-called consensus mechanism is a mathematical algorithm that establishes trust and obtains rights and interests between different nodes in the blockchain system [1].
Blockchain is an important concept of Bitcoin. The "2014-2016 Global Bitcoin Development Research Report" released by Huobi.com, Tsinghua University PBC School of Finance Internet Finance Laboratory and Sina Technology mentioned the area. Blockchain is the underlying technology and infrastructure of Bitcoin [2]. It is essentially a decentralized database and serves as the underlying technology of Bitcoin. Blockchain is a series of data blocks generated using cryptographic methods. Each data block contains information about a Bitcoin network transaction, which is used to verify the validity of its information (anti-counterfeiting) and generate the next block< br /> The evolution of blockchain is:
▪ Blockchain 1.0 - digital currency
▪ Blockchain 2.0 - digital assets and smart contracts
▪ Blockchain 3.0— —IFMChain, blockchain officially links mobile terminals