区块链是什么点对点传输共识机制,区块链点对点交易是什么意思

区块链是一种分布式的数据库，它是一种使用密码学原理，通过点对点传输共识机制，以技术手段保护数据安全性的新型数据库技术。它可以用来存储各种数据，例如货币、金融资产、智能合约、身份信息等，构建一个安全、可信赖、可审计的网络环境。

区块链点对点交易是指，在区块链网络中，用户之间可以直接进行资产交易，而不需要第三方的参与。通过点对点交易，可以极大的提高交易的安全性，确保交易双方的资产安全，以及交易的透明度。

关键词1：密码学密码学是一门研究密码系统，以及使用密码系统实现信息安全的学科。它的主要目的是保护信息的安全，确保信息传输的安全性和可靠性，以及保护信息的隐私性。主要的技术包括加密技术、数字签名技术、身份验证技术等。区块链技术是基于密码学原理，通过点对点传输共识机制，以技术手段保护数据安全性的新型数据库技术。

关键词2：点对点传输点对点传输是指在网络中，两个节点之间进行数据传输，而不需要经过中间节点，也不需要经过中心服务器。它是一种去中心化的传输方式，可以极大的提高数据传输的安全性、可靠性和速度，并且能够有效的降低传输成本。点对点传输是区块链技术的基础，它是一种使用密码学原理，通过点对点传输共识机制，以技术手段保护数据安全性的新型数据库技术。

关键词3：共识机制共识机制是指在分布式系统中，各个节点之间通过共同的规则，达成一致的结论或者接受某种行为的机制。它是一种去中心化的技术，可以有效的解决分布式系统中的安全性、可靠性和可信赖性问题。共识机制是区块链技术的核心，它是一种使用密码学原理，通过点对点传输共识机制，以技术手段保护数据安全性的新型数据库技术。

以上就是关于区块链是什么点对点传输共识机制、区块链点对点交易是什么意思拓展的3个相关关键词：密码学、点对点传输、共识机制的介绍，希望能够对你有所帮助。

① What is blockchain and where can I learn it

Definition of blockchain

In a narrow sense, blockchain is a chronological A chained data structure that combines data blocks in a sequential manner, and is cryptographically guaranteed to be an untamperable and unforgeable distributed 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, and uses cryptography to ensure Security of data transmission and access, a new distributed infrastructure and computing method that uses smart contracts composed of automated script codes to program and operate data.

There are many channels to learn about blockchain

① You can buy some blockchain-related books and learn some blockchain-related knowledge in your spare time. I can also take notes and look up relevant information

②Watch some blockchain videos on the Internet. The content is easy to understand and comes with relevant examples, which is also very good. a way of learning.

③You can participate in some offline blockchain learning and exchange meetings, or participate in some training courses, and teachers will specifically answer your questions.

To sum up

All roads lead to Rome, and there are many channels to learn blockchain. The one that suits you is the best

② Blockchain Core Technology - P2P Network

Peer-to-peer network is one of the core technologies in the blockchain. Its main focus is to provide a stable network structure for the blockchain for broadcasting unpackaged transactions ( Transactions in the transaction pool) and consensus blocks. Some consensus algorithms also require peer-to-peer network support (such as PBFT). Another auxiliary function, such as the Ethereum message network, also requires peer-to-peer network support.

P2P networks are divided into two categories: structured and unstructured networks. The structured network uses a similar DHT algorithm to build the network structure; the unstructured network is a flat network, and each node has the addresses of some neighbor nodes.

The main responsibilities of a peer-to-peer network are maintaining the network structure and sending information. The network structure should focus on the two aspects of adding new nodes and network updates, while sending information includes broadcast and unicast aspects

How to establish and maintain an entire point-to-point network? How to join and exit nodes?
There are two core parameters in establishing the network structure. One is the number of nodes connected to each node, and the second is the maximum number of forwardings.

The new node knows nothing about the entire network. It either obtains some nodes in the network to connect to through a central service, or connects to "seed" nodes in the network.

Network update processing When new nodes join or nodes exit, or even some nodes have poor network and cannot connect, after a whileAfter a while, he was alive again, waiting for these situations. These routing table changes are generally broadcast through the node's existing connections. It should be noted that due to the particularity of point-to-point networks, the routing table of each node is different (also called partial view)

Broadcasts generally use flooding protocols, that is, received and forwarded, so that When messages spread in the network, some restrictions are generally applied. For example, a maximum number of forwardings must be set for a message to avoid excessive load on the network.

Unicast requires the support of a structured network structure, usually DHT, which is similar to the DNS resolution method. It searches for the target node address hop by hop, then transmits it, and updates the local routing table.

To quickly retrieve information, there are two data structures that can be used. One is tree type, such as AVL tree, red-black tree, B-tree, etc.; the other is hash table.
Hash tables are more efficient than trees, but require more memory.
Information is represented in the form of key-value pairs, that is, a key corresponds to a value. What we are looking for is the key, and the value is the attached information.
The problem that the hash table needs to solve is how to evenly allocate a storage location to each key.
There are two key points here: 1. Allocate a storage location for the key. This allocation algorithm is fixed. Ensure that the same algorithm is used during storage and search, otherwise it will not be found after it is stored; 2. It should be distributed evenly. There should not be more data stored in some places and less data in some places.

Structures such as hashtable and map in general languages ​​are implemented using this technology. The hash function can directly use the modulo function, key%n. In this way, n represents the number of places, and the key is an integer. , if the key is of other types, a hash needs to be performed first to convert the key into an integer. This method can solve the above two requirements, but when n is not large enough (less than the data to be stored), conflicts will occur. There must be two keys to be stored in one place. At this time, one needs to be placed in this place. The linked list will be assigned to the same location, different keys, and placed in sequence. When there are too many keys in one location, the search speed of the linked list is too slow, and it needs to be converted into a tree type structure (red-black tree or AVL tree).

As mentioned above, hash tables are very efficient, but occupy content. This limitation can be solved by using multiple machines. In a distributed environment, the above locations can be understood as computers (later called nodes), that is, how to map a key to a node. Each node has a node ID, that is, the mapping of key->node id. This mapping The algorithm must also be fixed.
This algorithm also has a very important requirement, namely scaleability. When new nodes join and exit, the number of keys that need to be migrated should be as small as possible.

ThisThere are two typical structures of mapping algorithms, one is ring-shaped and the other is tree-shaped; the ring-shaped one is called consistent hashing algorithm, and the tree-shaped one is called kademlia algorithm.

The point selection algorithm is a mapping algorithm that solves key->node id. To put it figuratively, it means selecting the node in its life for a key.

Assuming we use 32 hashes, the total amount of key data that can be accommodated is 2**32, which is called hash space. The node ID is mapped to an integer, and the key is also mapped to an integer. The difference between the key hash and the node hash value is called the distance (if it is a negative number, take the modulus, not the absolute value). For example, the hash of a key is 100 (represented by an integer), and the hash of a node is 105, then The distance between these two is 105-100=5. Of course, other distance representations can also be used, such as subtraction in reverse, but the algorithm must be fixed. We map (place) the key to the node closest to it. If the distance is taken modulo, it seems that the node and key are placed on a ring, and the key belongs to the node closest to it from a clockwise angle.

The distance of the kademlia algorithm is represented by the numerical value after the XOR calculation of the key hash and the node hash (integer). From left to right, the more "same prefixes" there are, the greater the distance. Closer, the position is different the further to the left, the further away.
The embodiment of the tree structure is to regard the nodes and keys as the nodes of the tree. The number of bits supported by this algorithm is 160 bits, that is, 20 8 bytes. The height of the tree is 160, and each edge represents one bit.
The point selection algorithm is the same as consistent hashing. From all nodes, the node with the smallest distance from the key is selected as the destination of the key.

Since it is in a distributed environment, in order to ensure high availability, we assume that there is no central routing table. Without this routing table that can see the whole picture, it brings some challenges, such as how to discover nodes, Find node?
In P2P networks, a common method is for each node to maintain a partial routing table, which only contains routing information for some nodes. In the flooding algorithm, these nodes are random; in the DHT algorithm, the routing table is structured, and the nodes maintained are also selective. So how to reasonably select nodes that need to maintain routing information?

A simple approach is for each node to store information about nodes larger than it, so that a ring can be formed. However, there is a big problem and a small problem in doing so. The big problem is that each node knows too little information (only the hash and address of the next node). When a key is given, it does not know if there is any node in the network that is shorter than the distance to the key. So it first determines whether the key belongs to itself and the next node. If so, then the key belongs to the next node. If not, it calls the same method on the next node., this complexity is N (number of nodes). An optimization method is that the other nodes maintained by each node i are: i+2 1, i+2 2,...i+2**31. By observing this data, it is found that from near to far, the node is more Becoming more and more sparse. This can reduce the complexity to lgN

Each node saves the information of other nodes, including, from left to right, nodes that are different from this node in each bit, and selects at most k (algorithm hyperparameters). For example, on node 00110 (for demonstration purposes, select 5 digits), the node routing information to be saved is:
1****: xxx,....,xxx(k)
01: xxx,....,xxx(k items)
000: xxx,....,xxx(k items)
0010: xxx,....,xxx(k items)
00111: xxx,....,xxx(k)
The above line is called k-bucket. From a visual point of view, the closer you are to yourself, the denser the nodes are, and the further away you are, the sparser the nodes are. This route search and node search algorithm also has lgN complexity.

③ What are nodes in blockchain technology?

Nodes are where blocks are connected, and blocks need to be chained to be useful.
The core analysis:
1. Transparency, 2. Openness, 3. Information cannot be tampered with, 4. Decentralization,
5. Detailed analysis.
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. 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 irreversible. Tamper-proof and unforgeable distributed ledger.
2. Broadly speaking, blockchain technology uses block chain data structures to verify and store data, uses distributed node consensus algorithms to generate and update data, and uses cryptography to ensure data transmission and access. A new distributed infrastructure and computing method that securely uses smart contracts composed of automated script codes to program and manipulate data.

④ How to integrate blockchain and sharing economy

In general, grasping the essence of blockchain should be weak control, decentralization, autonomous mechanism, network architecture and coupling connect. The essence of blockchain should be a new social structure in the information society era that is completely different from industrial society. The five core points about blockchain have something in common with the sharing economy. The essence of the sharing economy is to abandon the old development mechanism and no longer imposeMobilize centralized resources and use decentralized social resources in a peer-to-peer manner to allow participants to participate, and each contribute and benefit in different ways.
Blockchain and sharing economy, two mutually relevant Internet hotspots, happen to have ample "space for cooperation." From theory to practice, there have been many bold explorations in the industry, and there have even been some phenomena that challenge traditional business models. In this way, the sharing economy tied to the blockchain will be a brand new business model and a new subversion of interpersonal relationships. I plan to invest in the blockchain industry. After all, in the Internet era, I searched for Guangzhou Xuanling Technology Co., Ltd. and looked at the web page. They are a company that develops software blockchain smart contracts. There are many cases developed and the team is strong.

⑤ Is the so-called blockchain real?

This seems unreliable. From an academic perspective, blockchain is a distributed data storage, point-to-point transmission, New application models of computer technologies such as consensus mechanisms and encryption algorithms. Blockchain is essentially a decentralized database.
For example, if you are a woman, every time your boyfriend says something disgusting to you or promises to buy you something, you immediately record it and send it to all your best friends, classmates, Colleagues, as well as various groups and circles of friends, make it impossible for him to deny it anymore. This is called blockchain.
The core advantage of blockchain technology is decentralization. It can achieve decentralized credit in a distributed system where nodes do not need to trust each other by using data encryption, timestamps, distributed consensus and economic incentives. Point-to-point transactions, coordination and collaboration, thereby providing solutions to the problems of high cost, low efficiency and insecure data storage common in centralized institutions.
The application fields of blockchain include digital currency, certificates, finance, anti-counterfeiting and traceability, privacy protection, supply chain, entertainment, etc. With the popularity of blockchain and Bitcoin, many related top domain names have been registered. , which has had a relatively large impact on the domain name industry.

⑥ What does blockchain mean?

Blockchain is a new application model of computer technology 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. As the underlying technology of Bitcoin, it is a series of data blocks generated using cryptographic methods. Each data block contains a batch of The information of Bitcoin network transactions is used to verify the validity of its information (anti-counterfeiting) and generate the next block.

Blockchain is closely related to people’s production and life in public management, energy, hotel management, transportation and other fields, but the centralized nature of these fields also brings some problems , can be transformed using blockchain.

The decentralized fully distributed DNS service can realize domain name query and transfer through point-to-point data transmission services between each other in the network.Analysis, the operating system and firmware that can be used for certain important infrastructures have not been tampered with, and the status and initialization of the software can be monitored to detect bad tampering and ensure that the data transmitted by the system using IoT technology has not been used. tamper.

⑦ What is peer-to-peer distributed technology in blockchain?

"A network-based computer processing technology, corresponding to centralized. Since the performance of personal computers has been greatly improved The improvement and popularization of its use make it possible to distribute processing power to all computers on the network. Distributed computing is a concept opposite to centralized computing, and the data of distributed computing can be distributed over a large area."

⑧ How are the blocks in the blockchain connected?

Experts said that the blockchain can be understood in a popular way as a distributed public ledger, which is connected by various blocks. into a chain. In traditional accounting systems, accounting rights are in the hands of the central server.

On the "ledger" of the blockchain, every point in the chain can record information on it, forming a point-to-point accounting system. Therefore, blockchain technology is considered a decentralized technology.

For example, in a village of 100 people, Zhang San bought a cow from Li Si and paid him 10,000 yuan. In the past, he had to rely on the middleman Zhao Liu to transfer his 10,000 yuan to Li Si.

With the blockchain system, Zhang San can directly record his 10,000 yuan into Li Si’s account book, and at the same time, the transaction information will be transmitted to the whole village, that is, the entire blockchain system. Make the information visible to 98 other people. The system records the entire transaction process, which has the advantage of traceability and prevents problems such as the loss of Zhao Liu's account book or Li Si's refusal to acknowledge the account.

(8) Point-to-point extended reading of Pulutong Blockchain

In 2008, Satoshi Nakamoto proposed the concept of blockchain for the first time. In the years that followed, blockchain became a core component of the electronic currency Bitcoin: serving as the public ledger of all transactions. By leveraging peer-to-peer networks and distributed timestamp servers, blockchain databases can be managed autonomously.

The blockchain invented for Bitcoin made it the first digital currency to solve the problem of repeated consumption. Bitcoin's design has become a source of inspiration for other applications.