p2p 区块链,区块链 p2p网络协议

⑴ What are the development solutions for blockchain P2P systems

Blockchain technology can effectively solve the current difficulties in the bill market and the P2P field (data in-depth mining and application, data security ), provide reliable technical support for effective supervision and low-cost supervision, and build a new trading platform for bill market innovation

In terms of system development plans, blockchain technology can currently be used to build There are not many companies, and the specific solutions that Yuzhan can currently find are those developed by Yingtang Zhongchuang. Its P2P system solution developed using blockchain technology can solve some problems encountered in big data credit investigation

⑵ Is the blockchain a friend or enemy of the sharing economy?

It depends on how you look at this issue.
The essence of the sharing economy is the seamless, direct and efficient sharing of information and resources between strangers, thereby creating value that benefits both parties. To achieve this goal, the prerequisite is to trust the other party and know the basics. But since they are strangers, where does mutual trust come from? As a result, platforms have emerged that provide a sense of trust and guarantee that promises will be fulfilled—Airbnb, Uber, and Didi Dache are among the best. By building and maintaining technology platforms, they aggregate, reorganize and allocate scattered resources and demands, verify the true identities, professional qualifications and background information of suppliers and demanders, provide transaction information, payment tools and review records, and finally facilitate transactions between both parties.
The future version of the sharing economy must open channels of mutual trust at the personal level, and blockchain is the key to opening channels. The sharing economy model is an emerging business model centered on P2P, and blockchain is an innovative digital technology that drives comprehensive P2P transactions. Both have exposed their respective vulnerabilities and risks, and there is huge room for improvement and a very long improvement period. . Blockchain and the sharing economy can be mutual partners or competing competitors. Whether it is an enemy or a friend depends on the attitude and perspective of the authorities - take the initiative, make arrangements, actively embrace the other party to consolidate and strengthen their own advantages, or wait for the day of marginalization? Airbnb, a leading company in the sharing economy, chose the former.
DECENT can also be regarded as one of the sharing economy projects, or as a blockchain project.

⑶ The more nodes in the blockchain, the safer it is. What are the characteristics of p2p?

The more nodes in the blockchain, the safer it will be, and p2p has the characteristics of high risk and high return. , so investors need to evaluate market risks and invest prudently.

⑷ What is the relationship between blockchain and P2P

1. It helps to supervise P2P companies

Regulatory departments (central bank, banking regulatory, securities regulatory) as regional As part of the blockchain, the public ledger of P2P transactions can be obtained in real time, and the financial management projects and fund transfer information of each P2P company can be obtained by analyzing the public ledger, providing low-cost, high-efficiency, and reliable regulatory data for P2P industry supervision in real time.

2. BorrowerTransparency of credit reporting

The main thing blockchain solves is the credit problem, so the most promising application of blockchain is in credit reporting. However, there is actually a lot of controversy in the area of ​​credit reporting. After all, credit reporting-related data is very sensitive. Neither credit reporting agencies nor users actually want it to be made public. Data is the lifeblood of credit reporting agencies, and everyone wants others to Make it public and keep it to yourself. Users also don’t want their data to be made public. Of course, if credit information can be made transparent in the future, it will still be very beneficial to P2P investors.

3. Low-cost transaction structure

For a P2P platform, the monthly cash withdrawal fees for users are also a large expense, but ordinary P2P platforms will Pay for this out of your own pocket. Applying the powerful online transaction function of blockchain to third-party payment or bank fund custody to complete fast, prepared and transparent transactions is a good thing for P2P platforms.

4. Industry Infrastructure Facilities

The rapid development of most things is largely due to the improvement of infrastructure. From the current point of view, blockchain technology can be regarded as a very important new infrastructure construction for P2P and even the entire Internet financial system, similar to the huge changes that highways have had on the automobile transportation industry and containers have changed the ocean transportation industry.

⑸ Is the p2p network a blockchain?

P2p means point-to-point, and the P2P network is a point-to-point network scenario, characterized by decentralization. Blockchain is a technical means for the development of P2P networks. It can be simply understood that a block is an account book that records all the information generated by the entire network in a certain period of time. In a p2p network, the exchange and synchronization of data between nodes requires huge computing power. Block technology was born to solve this problem.

⑹ Are p2p and blockchain worthy of attention and investment?

No. There has also been a trend in the past two years. I had the opportunity to participate, but I did not. One is p2p and one is blockchain.

When p2p was on the rise, many companies came to recruit me to do marketing, and some asked me to be a partner. There were also many cooperations in advertising and websites, but I refused them all.

I think most people are still suitable for steady and steady work, not for making quick money. It's nothing special to earn a lot, but it's a skill to earn it for a long time. Things that come quickly go away quickly because there is no threshold. In the end, it is very tiring to find projects all over again. It is better to choose a promising direction, do it in a down-to-earth manner for a long time, and rely on experience and resources to establish a threshold.

⑺ Blockchain core technology-P2P network

Peer-to-peer network is one of the core technologies in the blockchain. The main focus is to provide a stable network for the blockchain Structure, used to broadcast unpackaged transactions (transactions in the transaction pool) and consensus blocks. Some consensus algorithms also require point-to-point network support (such as PBFT), another auxiliary function, such as Ethereum’s message network, also requires the support of point-to-point networks.

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 for establishing a 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 occurs when new nodes join or nodes exit, or even when some nodes have poor network and cannot be connected, they come back alive after a while, etc. 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 isInteger, if the key is of other types, it needs to be hashed 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 too many keys are placed 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, which 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.

This mapping algorithm has two typical structures, 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 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.

BySo 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 and find nodes?
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. The 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.

⑻ Some people say that Bitcoin uses P2P technology, and some people say that it is a blockchain. What is going on?

The virtual encrypted digital currency of Bitcoin P2P technology is correct. This is a more essential statement. The term blockchain only came into being after the birth of Bitcoin, because it was Bitcoin that opened the door to the blockchain field. The popularity of Bitcoin has made more and more people pay attention to the blockchain. Chain technology, before the birth of blockchain, many veterans used to call it P2P, which is probably what it is. Including many of the world’s leadingExchanges such as OKEx have also developed some functions based on blockchain technology. You can learn more about it on the OKEx platform.

⑼ How to understand P2P in blockchain

Everyone must be familiar with the concept of P2P. The first reaction is online lending. In fact, in the world of blockchain, P2P refers to Wait for the network.

The concept of peer-to-peer network was proposed after the 2008 financial crisis. One or several people named Satoshi Nakamoto published an article on the Internet called "Bitcoin White Paper: A "Peer-to-Peer Electronic Cash System" paper, so a large number of technology geeks were attracted together. They continued to improve the Bitcoin system and eventually discovered the blockchain.

Satoshi Nakamoto said in the paper: In a peer-to-peer electronic cash payment system, third parties are of no value.

Here is what I understand as decentralization.

We are not sure of their ultimate goal, maybe to change the world and change the future? However, such technological inventions do stand on the opposite side of traditional centralized control.

How to understand this peer-to-peer network?

What impact will they have on traditional industries?

Take the previous p2p thunderstorm as an example.

In 2018, starting from June, the p2p market may be the most severe period. There are an average of about 5 platforms experiencing thunderstorms every day. Many investors of thunderstorm platforms may be in panic all day long. Or on the road to safeguarding rights. A search online revealed a tragic picture.

Let’s now think back to what we need to do when we are optimistic about a platform and ready to invest. Assume it is not a fund plate.

Register, bind your bank card, verify your identity, and recharge. At this time, your money is deposited on the platform, and then the platform will lend the funds to the borrowers who have connected and verified their identity in advance. If you After investing for one month, you can choose to withdraw the principal and collect the interest for the month at the end of each month, or you can continue bidding in it without withdrawing it.

Let’s give another closely related example

When we usually shop online on Taobao, we first need to bind the card to recharge the shopping payment and send it to Alipay. After confirming receipt of the goods, Alipay will send you The money is sent to the merchant. The deal is done.

You will find out by analyzing the above two examples. Before we invest or trade, our personal private information must be disclosed to a third party first. The platform and Alibaba you chose after you were optimistic about it act as a credit endorsement.

At the moment of transaction, subconsciously, we have already identified the platform and AlibabaThink of it as a platform that absolutely guarantees that our personal information will not be leaked and that our funds are safe.

At this time, the basis of our transactions is based on trust.

Given Alibaba’s strong public influence, it is believed that its possibility of running away and violating credibility is lower than that of p2p. But suppose, and I mean suppose, that our data and huge amounts of assets stored by these giants are attacked by hackers. If such a huge amount of data is leaked, we will definitely be at risk of losses, and it is completely out of our control.

Not to mention p2p, the information released by the company is untrue, or the company does not verify the borrower's information strictly, which distorts the information that should be honestly disclosed to investors. Needless to say, there are layers of shackles and risks.

Therefore, let’s understand what Satoshi Nakamoto said in the paper: In a peer-to-peer electronic cash payment system, the third party is worthless.

Peer-to-peer (p2p) in the blockchain is decentralization or weak centralization. It weakens the concept of intermediate nodes that control most of the data in traditional industries, making a blockchain network All nodes are functionally equal. Each node can provide services to other nodes, and can also use other nodes to provide services for itself.

And when such a behavior occurs, the entire network will automatically broadcast the backup, that is, it will be recorded in the ledger. Everyone will know that there is such a thing. If a person wants to default on the debt, he must change it. More than half of the ledgers in the network have huge costs and cannot be repudiated, ensuring the security of blockchain system data.

The characteristics of blockchain such as decentralization, security, transparent sharing, high efficiency, and low cost make its application scope very wide. However, the underlying technology of blockchain is not yet mature and the infrastructure is not yet mature. Perfect, the domestic blockchain industry is now in the early stages of development, and there are many traps. Therefore, our attention should not only be on currency prices and market conditions, but also on the real blockchain technology

When your own abilities are not enough, you must stay away from instigative investment behaviors. You would rather miss it than take risks with money in a hot-headed manner.

Original link: https://www.kg.com/article/490959733117816832