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Editor to share with you what is the core technology of blockchain, I believe that most people do not know much about it, so share this article for your reference, I hope you can learn a lot after reading this article, let's learn about it!

The four core technologies of the block chain: 1, the distributed account book, which plays the role of data storage in the block chain; 2, the consensus mechanism, which plays the role of co-ordinating the behavior of nodes in the block chain and clarifying the role of data processing; 3) cryptography, it can ensure data security and verify data ownership; 4. Intelligent contract plays the function of data execution and application in the block chain.

The operating environment of this tutorial: windows10 system, Dell G3 computer.

In fact, the blockchain has made great changes and progress on the original basis in the past ten years. Up to now, the four core technologies of the blockchain-- distributed ledger, consensus mechanism, cryptography and intelligent contract-- play an important role in data storage, data processing, data security, and data application. Generally speaking, each of the four core technologies has its own role in the block chain, and they work together to build the basis of the block chain.

First, distributed ledger-storage function

First of all, the distributed ledger constructs the framework of the blockchain, which is essentially a distributed database. When a piece of data is generated and processed by everyone, it will be stored in this database, so the distributed ledger plays the role of data storage in the blockchain.

Block chain consists of many nodes to form an end-to-end network, there is no centralized equipment and management organization, data exchange between nodes is verified by digital signature technology, there is no need for artificial mutual trust, as long as it is carried out in accordance with established rules. It is also impossible to deceive other nodes between nodes. Because the whole network is decentralized, everyone is a participant, and everyone has a say.

Second, consensus mechanism-- overall planning node, data processing

Secondly, because of the decentralized characteristics of the distributed ledger, the block chain network is a distributed structure, and everyone is free to join it and participate in the recording of the data, but at the same time, this gives rise to the headache of the "Byzantine General" problem, that is, the greater the number of participants in the network, the more difficult it is for the whole network to be unified, so another mechanism is needed to coordinate all-node accounts. The consensus mechanism formulates a set of rules to clarify the way in which everyone processes the data, and completes the unity of opinions between nodes by competing for the right to keep accounts. Finally, whoever gets the right to keep accounts will be used to process the data in the whole network. Therefore, the consensus mechanism plays the role of coordinating the behavior of nodes in the block chain and clarifying the role of data processing.

Anyone can participate in the blockchain network, each device can be used as a node, each node is allowed to obtain a complete database, and there is a set of consensus mechanism between nodes to jointly maintain the whole blockchain through competition, calculation and joint maintenance. If any node fails, the rest of the nodes can still work normally. It is equivalent to recognizing the rules of your game. Bitcoin has a Bitcoin consensus mechanism, and global recognition can participate in bitcoin mining, because you recognize its consensus mechanism and can also be understood as recognizing its rules of the game. The rule of Bitcoin is to do huge calculations, and whoever comes up with it first will reward POW.

Note: what are the advantages and disadvantages of consensus mechanism compared with PoW, PoS and DPoS?

PoW is workload proof, which is a very ingenious method, and its advantages are:

The algorithm is simple and easy to implement.

Nodes can reach a consensus without exchanging additional information.

It takes a great cost to destroy the system.

Its disadvantages are also obvious:

Waste of energy

It is difficult to shorten the confirmation time of blocks.

The new chunk chain must find a different hashing algorithm, otherwise it will face the arithmetic attack of bitcoin.

It is easy to bifurcate and need to wait for multiple confirmations.

There is never finality, and checkpointing mechanisms are needed to make up for finality.

PoS is the proof of rights and interests, which changes the computing power in PoW into system rights and interests. The greater the rights and interests, the greater the probability of becoming the next bookkeeper. The advantage of this mechanism is that it is not as power-consuming as Pow, but it also has many disadvantages:

Without specialization, participants with interests may not want to participate in bookkeeping.

It is easy to bifurcate and need to wait for multiple confirmations.

There is never finality, and checkpointing mechanisms are needed to make up for finality.

On the basis of PoS, DPoS specializes the role of bookkeeper, first selects bookkeeper through rights and interests, and then takes turns to keep accounts among bookkeepers. This approach still does not solve the ultimate problem.

DBFT (delegated BFT) is a general consensus mechanism module. An improved Byzantine fault-tolerant algorithm is proposed to make it suitable for block chain systems.

DBFT is a protocol based on block chain technology. Users can digitize the assets and rights and interests of the physical world and carry out decentralized network protocols for financial services such as registration and issuance, transfer transactions, clearing and delivery through peer-to-peer networks. Xiao Yi can issue shares in companies recognized by China's contract Law and Company Law, not only in the digital currency circle, but also in mainstream Internet finance. Ant can be used for equity crowdfunding, P2P network lending, digital asset management, intelligent contracts and so on.

This consensus mechanism is based on the practical Byzantine fault-tolerant algorithm (Practical Byzantine Fault Tolerance) proposed by Castro and Liskov. After improvement, it can be applied to block chain systems. Byzantine fault-tolerant technology is widely used in distributed systems, such as distributed file system, distributed collaboration system, cloud computing and so on. DBFT has mainly made the following improvements:

Improve the request response mode of Cpact S architecture to a peer-to-peer model suitable for P2P networks.

The static consensus participant node is improved to a dynamic consensus participant node that can enter and exit dynamically.

A voting mechanism based on the proportion of equity held is designed for the generation of consensus participating nodes, and the consensus participating nodes (accounting nodes) are decided by voting.

The digital certificate is introduced into the block chain to solve the problem of authenticating the real identity of the accounting node in the voting.

Why did you end up with such a scheme?

A: blockchain is a distributed ledger system, and its internal economic model determines that each participant does not have to trust other participants, that is, the so-called de-trust. The Byzantine General problem describes how participants reach a consensus without trust, and Byzantine fault-tolerant technology is the way to solve this kind of problem. In addition, the network environment of blockchain is very complex, which will face network delays, transmission errors, software errors, security vulnerabilities, hackers and other problems, as well as a variety of malicious nodes. Byzantine fault-tolerant technology is a solution that can tolerate these errors.

In the dBFT mechanism, the bookkeeper is selected by rights and interests, and then the bookkeepers reach a consensus through the Byzantine fault-tolerant algorithm. The advantages of this approach are:

A professional bookkeeper

Can tolerate any type of error

Bookkeeping is done by multiple people, each block has finality and will not bifurcate.

The reliability of the algorithm is strictly proved by mathematics.

Disadvantages:

When the bookkeeper stops working, the system will not be able to provide service.

When one or more bookkeepers join forces to do evil, and all other bookkeepers happen to be divided into two network islands, malicious bookkeepers can bifurcate the system, but leave cryptographic evidence.

To sum up, the core point of the dBFT mechanism is to maximize the finality of the system, so that the blockchain can be applied to the real financial application scenarios. For example, the consensus mechanism of Columbus, the consensus mechanism of DPOS+DBFT. If one of our entire nodes or one of the devices is turned off, then the other nodes are still working normally and will not affect the entire network system. But if Tencent's server is shut down, everyone's Wechat won't open, because you have no place to access data, which is the difference between a centralized network server and a blockchain network server.

Third, cryptography-- data security, verifies the attribution of the data, can not be tampered with and can be traced back.

In addition, the data is not simply packaged into the distributed database, but the underlying data architecture is determined by block chain cryptography. the packaged data blocks will be processed into a chained structure through the hash function in cryptography, and the latter block contains the hash value of the previous block, because the hash algorithm is unidirectional and tamper-resistant, so it is only in the block chain network. Once the data is linked, it cannot be tampered with and can be traced back. In addition, your account will also be encrypted by asymmetric encryption, thus ensuring the security of the data and verifying the ownership of the data.

Modifications to single or multiple databases cannot affect other databases. This is almost impossible except that more than 51% of the data for the entire network is modified at the same time. Each transaction in the blockchain is connected to two adjacent blocks in a cryptographic way, so it can be traced back to the past life of any transaction. Here is the data structure of the block chain, block head and block. Cryptographic hash value, timestamp, through the timestamp to determine its order, will not be disturbed.

This principle applies to our business system, including the commodity system, and what we call traceability can find out where the goods are produced and what the raw materials are, step by step from back to forward. because we write the information data into the block chain system at the same time, through this system, I can find out whether the raw material is used. Whether it is produced by this process. Through the structural storage of such a data to achieve our common belief in it, this product is indeed produced in this way, I believe it is true.

In addition, the data can not be modified, if you want to change to reach 51% of the talent can, from the equity understanding, own 51% of the company will have a say in the company. It's just a possibility. Why is it more harmful and safer to use blockchain technology than Internet technology? because it is distributed, if you want to modify the data inside, as a hacker wants to find all the computers that keep this account, every computer has to be modified. maybe you can find one of them quickly to change it, but it's hard to change it all.

All the transaction information in the block chain is public, so every transaction is visible to all nodes. Because the nodes are decentralized, there is no need to disclose the identity between the nodes, and each node is anonymous. For example, after each computer starts, we don't know who starts or doesn't start each other. You can turn it on in your home. There is a problem of more work, more pay.

Fourth, intelligent contract-execution application

Finally, intelligent contracts at the application level can be built on the basis of distributed account books. When we want to solve some trust problems, we can use the intelligent contract to list the conditions clearly in the form of code, and execute the conditions through the program, while the data in the block chain can be called through the intelligent contract. So Zhitong contract plays the function of data execution and application in the block chain.

Smart contracts can help you exchange money, property, shares or anything of value in a transparent and conflict-free manner, while avoiding the services of middlemen and even saying that smart contracts will replace lawyers in the future. Through a smart contract, the asset or currency is transferred to the program, and the program runs the code and automatically validates a condition at some point in time, which automatically determines whether the asset should go to one person or go back to another. or it should be returned immediately to the person who sent it or its combination. At the same time, decentralized books also store and copy files, making them secure and immutable.

Features of smart contracts

Autonomy-abolish middlemen and third parties, you are the one who reached the agreement; there is no need to rely on brokers, lawyers, or other middlemen to confirm. By the way, this also eliminates the danger of third-party manipulation, as execution is automatically managed by the network, not by one or more potentially biased individuals who may make mistakes.

Trust-your files are encrypted on shared books. Some people can't say they lost it.

Backup-imagine if your bank loses your savings account. On the blockchain, each of your friends has your back. Your document has been repeated many times.

Security-cryptography, website encryption, to ensure the security of your files. There was no hacker attack. In fact, it takes a very clever hacker to crack the code and infiltrate it.

Speed-you usually have to spend a lot of time and paperwork processing documents manually. Smart contracts use software code to automate tasks, thus reducing the time of a series of business processes.

Save money-smart contracts can save you money because they eliminate middlemen. For example, you must pay a notary to witness your transaction.

Accuracy-Automation contracts are not only faster and cheaper, but also avoid errors caused by filling out forms by hand.

The best way to describe smart contracts is to compare the technology with vending machines. Usually, you go to a lawyer or notary, pay them, and wait for you to get the documents. With a smart contract, you simply put a bitcoin in a vending machine (such as a ledger) and put your escrow, driver's license or anything in your account. More importantly, smart contracts not only define the rules and penalties of the agreement in the same way as traditional contracts, but also automatically implement these obligations.

Intelligent contract and Block chain

The best thing about blockchain is that because it is a decentralized system that exists between all allowed parties, there is no need to pay a middleman (middleman), which can save you time and conflict. Blockchains are problematic, but their ratings are undeniably faster, cheaper and safer than traditional systems, which is why banks and governments turn to them. Using the characteristics of blockchain technology to apply to intelligent contracts, it will be more convenient to improve a variety of contracts in work and life.

These are all the contents of the article "what is the Core Technology of blockchain". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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