区块链关键技术怎么写论文,区块链关键技术包括哪些

近年来，区块链技术已经成为了一个热门话题，它不仅可以改变传统金融行业，还可以改变其他行业，如政府、法律、物流和医疗等。本文将讨论区块链技术的关键技术，以及它们如何影响我们的日常生活。

区块链技术的关键技术包括分布式账本，数字签名，智能合约，共识机制，隐私保护等。分布式账本是区块链的基础，它是一种分布式的、可验证的、可信任的账本，它可以存储数字资产的信息，以及它们之间的交易记录。数字签名是一种用于确认交易的技术，它可以帮助用户确认交易的发起者的身份，从而保护交易的安全性。智能合约是一种可以自动执行的计算机程序，它可以用来执行复杂的交易，而不需要人为干预。共识机制是一种用于确认交易的技术，它可以帮助网络中的节点（节点）确认交易的正确性，从而确保网络的安全性。隐私保护是一种用于保护数据的技术，它可以帮助用户保护其隐私，从而保证数据的安全性。

区块链技术的关键技术不仅可以改变传统金融行业，还可以改变其他行业，如政府、法律、物流和医疗等。例如，政府可以利用区块链技术来实现更加透明和安全的数据管理，从而提高公共服务的效率。此外，法律行业可以利用区块链技术来实现更加安全和可靠的数据存储，从而提高司法效率。物流行业可以利用区块链技术来实现更加有效的物流管理，从而提高物流效率。最后，医疗行业可以利用区块链技术来实现更加安全和可靠的数据存储，从而提高医疗效率。

总之，区块链技术的关键技术可以帮助我们改变传统金融行业，也可以改变其他行业，如政府、法律、物流和医疗等。它们可以帮助我们提高数据的安全性和可靠性，从而提高各行业的效率。因此，区块链技术的关键技术可以为我们的日常生活带来很大的方便。

① What is the core technology of blockchain

To put it simply, blockchain is a distributed database that provides Byzantine fault tolerance and ensures ultimate consistency; From the data structure point of view, it is a chained data block structure based on time series; from the node topology point of view, all its nodes are redundant backups of each other; from the operation point of view, it provides a public and private key management system based on cryptography to manage the account.
Perhaps the above concept is too abstract, let me give you an example so that you can understand it easier.
You can imagine that there are 100 computers distributed around the world. The network between these 100 machines is a wide area network, and the owners of these 100 machines do not trust each other.
So, what kind of algorithm (consensus mechanism) do we use to provide it with a trustworthy environment and make:
The data exchange process between nodes cannot be tampered with, and the generated historical records It cannot be tampered with;
The data of each node will be synchronized to the latest data, and the validity of the latest data will be verified;
Based on the principle of the minority obeying the majority, the data maintained by the overall node can objectively reflect the exchange history.
Blockchain is a technical solution created to solve the above problems.
2. The core technology components of blockchain
Whether it is a public chain or a consortium chain, it requires at least four modules: P2P network protocol, distributed consistency algorithm (consensus mechanism), encryption signature algorithm, Account and storage model.
1. P2P network protocol
P2P network protocol is the lowest module of all blockchains and is responsible for network transmission and broadcast of transaction data, node discovery and maintenance.
Usually what we use is the Bitcoin P2P network protocol module, which follows certain interaction principles. For example: when connecting to other nodes for the first time, you will be required to confirm the status according to the handshake protocol. After the handshake, you will start to request the address data and block data of the Peer node.
This P2P interactive protocol also has its own set of instructions, which are reflected in the command field of the Message Header. These commands provide the upper layer with node discovery, node acquisition, block header acquisition, Block acquisition and other functions, these functions are very low-level and very basic functions. If you want to learn more, you can refer to the Peer Discovery chapter in the Bitcoin Developer Guide.
2. Distributed consensus algorithm
In the field of classic distributed computing, we have non-Byzantine fault-tolerant algorithms represented by the Raft and Paxos algorithm families, as well as the PBFT consensus algorithm with Byzantine fault-tolerant characteristics.
If we look at it from the perspective of technological evolution, we can draw a picture in which blockchain technology has expanded the original distributed algorithm economically.
In the pictureWe can see that computer applications were mostly single-point applications at the beginning, and cold disaster recovery was used for high availability and convenience. Later, they developed into multi-active in different places. These multi-active in different places may use load balancing and routing technologies. With the distribution With the development of traditional system technology, we have transitioned to distributed systems based on Paxos and Raft.
In the field of blockchain, PoW workload proof algorithm, PoS equity proof algorithm, and DPoS proxy equity proof algorithm are mostly used. The above three are the mainstream consensus algorithms in the industry. These algorithms are similar to the classic distributed consensus algorithm. The difference is that they incorporate the concept of economic games. Below I will briefly introduce these three consensus algorithms respectively.
PoW: Usually refers to solving a mathematical problem of specific difficulty under given constraints. Whoever solves it faster can obtain the right to bookkeeping (block production). This solution process is often converted into a calculation problem, so when competing for speed, it becomes who has a better calculation method and whose equipment has better performance.
PoS: This is a proof-of-stake mechanism. Its basic concept is that the difficulty of generating a block should be proportional to your stake (ownership ratio) in the network. The core idea of ​​its implementation is: Use the coin age (CoinAge) of your locked tokens and a small proof of work to calculate a target value. When the target value is met, you will be able to obtain accounting rights.
DPoS: A simple understanding is to convert the bookkeepers in the PoS consensus algorithm into a small circle composed of a specified number of nodes, instead of everyone can participate in bookkeeping. This circle may have 21 nodes or 101 nodes, depending on the design. Only nodes in this circle can obtain accounting rights. This will greatly improve the throughput of the system, because fewer nodes means that the network and nodes are controllable.
3. Encrypted signature algorithm
In the field of blockchain, the most commonly used hash algorithm is the hash algorithm. The hash algorithm has the characteristics of collision resistance, irreversibility of the original image, and problem friendliness.
Among them, problem friendliness is the basis for the existence of many PoW currencies. In Bitcoin, the SHA256 algorithm is used as the calculation method for proof of work, which is what we call the mining algorithm.
In Litecoin, we will also see the Scrypt algorithm, which is different from SHA256 in that it requires large memory support. In some other currencies, we can also see mining algorithms based on the SHA3 algorithm. Ethereum uses an improved version of the Dagger-Hashimoto algorithm, named Ethash, which is an IO-intractable algorithm.
Of course, in addition to the mining algorithm, we will also use the RIPEMD160 algorithm, which is mainly used to generate addresses. Most of the numerous Bitcoin derivative codes adopt the Bitcoin address design.
In addition to addresses, we will also use the core and the cornerstone of the blockchain Token system: public and private key cryptographic algorithms.
In the Bitcoin code, ECDSA is basically used. ECDSA is a combination of ECC and DSA. The entire signature process is similar to DSA. The difference is that the algorithm used in the signature is ECC (Elliptic Curve Function).
Technically, we start by generating a private key, then generate a public key from the private key, and finally generate an address from the public key. Each of the above steps is an irreversible process, which means that the public key cannot be derived from the address. , derived from the public key to the private key.
4. Account and transaction model
From the initial definition, we know that blockchain can be considered a distributed database from a technical perspective only. So, what type of database do most blockchains use? What about the database?
When I designed the Metaverse blockchain, I referred to a variety of databases, including NoSQL’s BerkeleyDB and LevelDB, and some currencies use SQL-based SQLite. As the underlying storage facilities, most of them are lightweight embedded databases. Since they do not involve the ledger characteristics of the blockchain, these storage technologies are no different from those used in other situations.
The ledger characteristics of blockchain are usually divided into UTXO structure and ledger structure based on Accout-Balance structure, which we also call the ledger model. UTXO is the abbreviation of "unspent transaction input/output", which translated means "unspent transaction input/output".
This is an accounting mode for Token transfer in the blockchain. Each transfer appears in the form of input and output; in the Balance structure, there is no such mode.

② What technology development is needed for blockchain

What technology development is needed for blockchain:
1. Blockchain theory: Blockchain developers must understand the blockchain Theoretical knowledge and familiarity with it are the most basic requirements for a blockchain developer. The content includes blockchain network architecture, decentralization and other related application technologies. Expanding technical theory is mastery of Ethereum development.
2. Smart contract: Smart contract is a string of codes that blockchain developers need to write in blockchain programming language. It is a trust mechanism developed after imagining logic according to different scenarios, aiming to eliminate the intervention of third parties. Create an efficient and high-trust blockchain network. Blockchain developers need to realize automatic execution of this string of code, and the operation effect is irreversible.
3. Cryptography: Many blockchain application scenarios have high encryption, and point-to-point encryption mode is a characteristic of cryptography. By studying cryptography, blockchain developers understand cryptographic concepts such as wallets, keys, and a wide range of encryption and decryption technologies
4. Distributed Architecture: Blockchain DevelopersMust understand distributed architecture and network functionality. Decentralized network is the foundation of the blockchain architecture. The transmission of information in the blockchain network must follow a decentralized approach so that everyone can enjoy the same network rights.

③ Key technologies of blockchain

Peer-to-peer distributed technology.

Rely on the computing power and bandwidth of participants in the network, rather than aggregating dependencies on a smaller number of servers. The advantages of P2P technology are obvious. The point-to-point network distribution feature also increases the reliability of failure prevention by replicating data on multiple nodes, and in a pure P2P network, nodes do not need to rely on a central index server to discover data. In the latter case, there is no single point of collapse for the system.

(3) How to write the key technologies of blockchain Extended reading:

Notes:

For blockchain information provision Anyone (project party) who develops and launches new products, new applications, or new functions must report to the national and provincial, autonomous region, or municipality Internet Information Offices for security assessment in accordance with relevant regulations.

Old blockchain application projects must first be registered with the provincial Cyberspace Administration of China in accordance with the new regulations. The registration will be obtained after 20 working days, and the registration number will be obtained or the registration will not be filed after 20 working days. , explain the reasons for not filing.

④ What are the core blockchain technologies of blockchain technology?

What is the hottest Internet topic at the moment? You don’t need to explain it to the editor to know that it is the blockchain. 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.
CoreTechnology 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 function is very simple. 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 and 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, and 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 requires nodes to provide proof of a certain number of tokens to obtain a distributed consensus mechanism for competing for blockchain accounting rights. 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 use in public chains. If you build a private chain, there is no verification node.For trust issues, it is more appropriate to use POS; and due to the existence of untrustworthy local nodes in the alliance chain, it is more appropriate 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 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 for that 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.

⑤ What are the blockchain technologies?

The concept of blockchain can be said to be very popular. At the Internet Finance Summit, no one said that blockchain technology is out. What is chain technology?

Blockchain technology can be either a public classification (anyone can see it) or a permissioned network (only permissioned people can see it), solving supply chain challenges. Because it is An immutable record, so it is shared among network participants and updated in real time.

Blockchain technology - data layer: Designing the data structure of the account book

Core technology 1. Block_ _;Chain:

Technically, a block is a data structure that records transactions, reflecting the capital flow of the transaction. The transaction blocks that have been reached in the system are connected to form the main chain, and all nodes participating in the calculation are Recorded 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 includes the current version number, previous block address, and timestamp ( Record the time when the block was generated (accurate to the second), random number (record the answer value to the mathematical question related to decrypting the block), the target hash value of the current block, the root value of the Merkle number source 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 The principle of converting from Hash algorithm to fixed-length code is a one-way hash function based on cryptography. This function is easy to verify, but difficult to interpret. The industry usually expresses this hash function in the form of y=hash(x). Realizes the hash value y of computing x.

Commonly used hash algorithms include MD5, SHA-1, SHA-256, SHA-384, SHA-512, etc. Taking the SHA256 algorithm as an example, any When data is input into SHA256, a 256-bit Hash value (hash value) will be obtained. Its characteristics: the same data input will get the same result. A slight change in the input data (for example, 1 becomes 0) will get a completely different result. The result measurement .Forward calculation (the Hash value corresponding to data calculation) is very simple. Reverse calculation is extremely difficult and is considered impossible under current scientific and technological conditions.

Core technology 3. Merkle tree:

Merkle tree is a hash binary tree that can quickly verify the integrity of large-scale data. In the blockchain network, Merkle Gray boy's side ⒌ Nai Cheng still V bear oars fishy Wei said that Hui boy's side ⒌ seek Xi Ji Cong's plan_erkle trees.

Core technology 4. Asymmetric encryption algorithm:

Non- The symmetric encryption algorithm is a key confidentiality method that requires a key and a key. The public key and the private key are a pair. If the public key is used to encrypt data, it can only be decrypted with the corresponding private key to obtain the corresponding data value. If the private key is used to sign, Data, the signature can only be verified with the corresponding public key, and the sender of the verification information is the owner of the private key.

Since encryption and decryption use two different keys, the algorithm is called asymmetric encryption algorithm, while symmetric encryption uses the same key in the encryption and decryption process.

Blockchain mitigation technology - network layer: achieving centralization of charging nodes

Core technology 5, P2P network:

P2P network (peer-to-peer network), also known as peer-to-peer technology, is an Internet system without a central server and user groups exchanging information. Unlike a central network system with a central server, a peer-to-peer network Each client is a node and also has the function of a server. Domestic Xunlei software uses P2P technology. The P2P network has the characteristics of centralization and reinforcement.

Blockchain technology-consensus layer: allocate charging nodesTask load

⑥ Introduction to blockchain technology What is blockchain technology

1. Blockchain technology is one of the top ten typical judicial technology applications on the Internet.

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

3. Generally speaking, the blockchain system consists of data layer, network layer, consensus layer, incentive layer, contract layer and application layer.

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

5. The consensus mechanism of the blockchain has the characteristics of "the minority obeys the majority" and "everyone is equal". Among them, "the minority obeys the majority" does not entirely refer to the number of nodes, but also to computing power. , number of shares, or other characteristic quantity that a computer can compare. "Everyone is equal" means that when a node meets the conditions, all nodes have the right to give priority to the consensus result, which will be directly recognized by other nodes and may eventually become the final consensus result. Taking Bitcoin as an example, Caizihe uses proof of work. Only if he controls more than 51% of the accounting nodes in the entire network, is it possible to forge a non-existent record. When there are enough nodes joining the blockchain, this is basically impossible, thus eliminating the possibility of fraud.

⑦ Characteristics of blockchain technology

The five basic characteristics of blockchain technology are as follows:
1. Characteristics of blockchain technology 1: distributed database
Every party on the blockchain has access to the entire database and its complete history. No single party controls the data or information. Each party can directly verify the records of its trading partners without the need for a middleman.
2. Blockchain technology feature 2: Peer-to-peer transmission
Communication occurs directly between peers, rather than through a central node. Each node stores and forwards information to all other nodes.
3. Characteristics of blockchain technology three: Transparent anonymity
Any user with access to the system can see each transaction and its associated values. Each node or user on the blockchain has a unique address consisting of more than 30 letters and numbers, which is used to identify itself. Users can choose to remain anonymous or provide proof of their identity to others. The addition of the blockchain occurs at one of these addresses.
4. Blockchain technology feature four: Irreversibility of records
Once a transaction is entered in the database and an account is updated, the records cannot be changed because they are linked to every transaction record before them (hence the name "chain"). Various algorithms are employed to ensure that records in the database are permanent, chronologically ordered, and accessible to all other nodes on the network.
5. Features of Blockchain Technology Five: Computational Logic
The digital nature of the ledger means that blockchain transactions can be associated with computational logic and are essentially programmable. Therefore, users can set algorithms and rules that automatically trigger transactions between nodes.
Extended information:
Blockchain is a chain composed of blocks one after another. Each block stores a certain amount of information, and they are connected into a chain in the order in which they were generated. This chain is saved in all servers. As long as one server in the entire system can work, the entire blockchain is safe. These servers are called nodes in the blockchain system, and they provide storage space and computing power support for the entire blockchain system. If you want to modify the information in the blockchain, you must obtain the consent of more than half of the nodes and modify the information in all nodes. These nodes are usually in the hands of different subjects, so it is extremely difficult to tamper with the information in the blockchain. thing. Compared with traditional networks, blockchain has two core characteristics: data is difficult to tamper with and decentralized. Based on these two characteristics, the information recorded in the blockchain is more authentic and reliable, and can help solve the problem of people's mutual distrust.

⑧ What is the core technology of blockchain

Introduction to the 7 core technologies of blockchain operation
2018-01-15
1. Blockchain Chain links
As the name suggests, blockchain is a chain composed of blocks. Each block is divided into two parts: block header and block body (including transaction data). The block header includes the hash (PrevHash) value (also called hash value) of the previous block used to implement block linking and the random number (nonce) used to calculate the mining difficulty. The hash value of the previous block is actually the hash value of the header of the previous block, and the rules for calculating random numbers determine which miner can obtain the power to record the block.
2. Consensus Mechanism
Blockchain was born with Bitcoin and is the basic technical architecture of Bitcoin. Blockchain can be understood as a decentralized accounting system based on the Internet. A decentralized digital currency system like Bitcoin requires blockchain to ensure the consistency of accounting by each honest node without a central node. So the core of blockchain technologyThe heart is a consensus mechanism that reaches a consensus on the legality of transactions among individuals who have no basis for trust in each other without central control.
There are currently four main categories of blockchain consensus mechanisms: PoW, PoS, DPoS, and distributed consensus algorithms.
3. Unlocking script
Script is an important technology for automatic verification and automatic execution of contracts on the blockchain. Each output of each transaction does not strictly point to an address, but to a script. A script is like a set of rules that govern how the recipient can spend the assets locked on this output.
The legality verification of transactions also relies on scripts. Currently it relies on two types of scripts: locking scripts and unlocking scripts. The locking script is a condition added to the output transaction, implemented through a script language, and is located at the output of the transaction. The unlocking script corresponds to the locking script. Only if the conditions required by the locking script are met, the corresponding assets on this script can be spent, which is located at the input of the transaction. Many flexible conditions can be expressed through scripting languages. The interpretation script is similar to a "virtual machine" in our programming field, which is distributed and runs on every node in the blockchain network.
4. Transaction Rules
Blockchain transactions are the basic units that constitute blocks, and are also the actual effective content that the blockchain is responsible for recording. A blockchain transaction can be a transfer or other transactions such as the deployment of smart contracts.
In the case of Bitcoin, a transaction refers to a payment transfer. The transaction rules are as follows:
1) The input and output of the transaction cannot be empty.
2) For each input of the transaction, if its corresponding UTXO output can be found in the current transaction pool, the transaction will be rejected. Because the current transaction pool is a transaction that has not been recorded in the blockchain, and each input of the transaction should come from a confirmed UTXO. If found in the current transaction pool, it is a double spend transaction.
3) For each input in the transaction, its corresponding output must be UTXO.
4) Each input unlocking script (unlocking
) must work with the corresponding output locking script (locking
) to verify the compliance of the transaction.
5. Transaction priority
The priority of blockchain transactions is determined by the blockchain protocol rules. For Bitcoin, the priority of a transaction being included in a block is determined by the time it takes for the transaction to be broadcast to the network and the size of the transaction. As the time it takes for a transaction to be broadcast to the network increases and the chain age of the transaction increases, the priority of the transaction is increased and will eventually be included in the block. For Ethereum, the priority of a transaction is also related to the transaction fee that the publisher of the transaction is willing to pay. The higher the transaction fee that the publisher is willing to pay, the higher the priority of the transaction being included in the block.
6.Merkle proof
The original application of Merkle proof is the Bitcoin system (Bitcoin), which was developed by Satoshi
Nakamoto) described and created in 2009. The Bitcoin blockchain uses Merkle proofs in order to store transactions in every block. This makes the transaction unable to be tampered with and makes it easy to verify whether the transaction is included in a specific block.
7.RLP
RLP (Recursive
Length
Prefix, recursive length prefix encoding) is a main encoding method for object serialization in Ethereum. Its purpose is to encode any nested A sequence of binary data is encoded.