区块链与dns的关联性,区块链与dns的关联是什么

近年来，区块链技术在金融、物联网、资产管理等领域取得了巨大的成功，并且在这些领域中发挥着重要的作用。另一方面，DNS（域名系统）也是一项重要的技术，它被广泛应用于互联网中，用于解析域名和IP地址之间的关系。最近，区块链和DNS技术开始结合在一起，并取得了不错的成果。

首先，区块链技术可以提高DNS的安全性。由于区块链的分布式特性，它可以有效地防止DNS的攻击，例如拒绝服务攻击（DDoS）。此外，区块链技术还可以改善DNS的可靠性，使得DNS的服务更加可靠，可以更好地支持客户端的访问。

其次，区块链技术可以改善DNS的隐私性。传统的DNS技术存在一定的安全和隐私风险，因为它可以被第三方追踪和攻击。而区块链技术可以通过加密技术和分布式技术来改善DNS的隐私性，使得DNS的信息更加安全。

此外，区块链技术还可以改善DNS的可扩展性。由于区块链的分布式特性，它可以更有效地管理DNS的数据，从而更容易地支持DNS的扩展。

总之，区块链技术与DNS技术的结合可以极大地改善DNS的安全性、可靠性、隐私性和可扩展性，为互联网提供更安全、可靠、可扩展的服务。因此，区块链技术与DNS技术的结合对于改善互联网的安全性和可靠性具有重要的意义。

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Ⅰ 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 platform for the blockchain. The network structure is 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), and another auxiliary function, such as Ethereum messages 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 to ensure storage and search.Use the same algorithm when saving, otherwise you will not find it after saving it; 2. It is distributed evenly, and you cannot store more data in some places and less data in others.

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 order. 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, 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, the modulus must be taken, 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. 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.

II Blockchain technology empowers Web3.0

Web3.0 will be a valueThe Internet, its openness, trust establishment and identity management are very different from Web2.0. The development of blockchain has just established the basic technical foundation for Web3.0 and will play a key role in Web3.0. In Web3.0, blockchain-related technologies include: peer-to-peer network technology, data storage and exchange systems, digital identities, blockchain-based financial networks, blockchain-based trust systems and smart contracts, etc.

Web 3.0 was originally called the Semantic Web by Tim Berners-Lee, the inventor of the World Wide Web (WWW), and its goal is to become a more autonomous, intelligent and open Internet. The definition of Web 3.0 can be expanded as follows: Data will be interconnected in a decentralized manner, which will be a huge leap from our current Internet. In Web 2.0, data was mainly stored in centralized repositories. Additionally, users and machines will be able to interact with the data. To do this, the program needs to understand the information conceptually and contextually. With this in mind, two cornerstones of Web 3.0 are the Semantic Web and artificial intelligence (AI).

From the perspective of users (users), Web3.0 and Web2.0 will be improved in many aspects in terms of presentation and experience. The following features are some of the aspects recognized by the industry: < br />
At the same time, with the development of network capabilities, artificial intelligence, and the explosive growth of data, the construction of Web3.0 networks will be a disruptive development for Web2.0, which reflects Web 3.0 will inevitably be an open, trustless, permissionless network, thereby realizing the true vision of the Internet.

Web3.0 will be a value Internet, and its openness, trust establishment and identity management are very different from Web2.0. The development of blockchain has just established the basic technical foundation for Web3.0 and will play a key role in Web3.0. In Web3.0, blockchain-related technologies include: peer-to-peer network technology, data storage and exchange systems, digital identities, blockchain-based financial networks, blockchain-based trust systems and smart contracts, etc.

Peer-to-peer network system: P2P Networking

The network architecture adopted by Web1.0 and 2.0 revolves around the architecture of the core network, access network and local area network. Such a network is basically a star structure, with data exchanged from the end up through the access network to the core network, and then routed down to its destination address. Internet applications rely on relatively centralized computing and storage. Once the network fails or is overwhelmed, service failure will occur immediately. Service failures of Internet giants are common and have huge impacts.

The Web3.0 network will be more flexibleData communication is more based on point-to-point networks. Point-to-point networks rely on the existing architecture of Web2.0 as infrastructure, and build a virtual P2P network layer on top of it. Each user node/terminal is connected to multiple terminal nodes at the same time, and network communication occurs through direct connections between terminals or through third-party relays. Such a connection has many benefits, such as: nodes can obtain information from multiple paths at the same time, so the data access speed can be more efficient; when there are multiple copies of data, information can be obtained from the nearest node, and network resource utilization is high ; The tolerance for network failures is greatly improved, and partial network failures will not affect the communication effect; the network links are abundant and the data transmission speed is very fast.

Peer-to-peer networking is also the basis for ensuring other features of Web3.0, which we will describe in the following sections. LibP2P is currently a relatively mature peer-to-peer network technology. Networks including IPFS, Filecoin, Ethereum2.0 and other platforms that provide services for Web3.0 are all built on LibP2P.

Terminals using point-to-point networks need to continuously maintain and maintain a large number of network links, and can intelligently perceive network problems and resist malicious links and attacks. This brings challenges to the development of P2P networks. At the same time, the P2P network is built on the basis of the existing network and requires comprehensive support for existing network protocols. Affected by the network scale effect, the development of the P2P network will first start with the technical facilities related to the blockchain and gradually Expand to a wider area.

Data storage and exchange system - The Underlying File System

Web1.0 and Web2.0 are built on the HTTP protocol. The HTTP protocol provides a simple file access method through path (URL), and users can access files and web content through URL.

HTTP is a client/server communication protocol, which forms the basis for almost all data exchanges on the current Internet. The term client-server means that there is a requesting party (the client - usually a web browser) that requests information from the server (the computer that provides the information - usually a web page or part of a web page). This protocol relies on Domain Name Server (DNS) servers to locate file paths. The DNS server itself is a large network that includes thirteen root servers, as well as numerous zone servers linked down. The DNS service network itself is a centralized network, and some attacks are directly targeted at the DNS network.

With Web 3.0, this mechanism is changing. The technology most likely to replace the current DNS system is called interplanetaryInterPlanetary File System, referred to as IPFS. When HTTP is gradually replaced by IPFS, indeed, we may be inclined to call it Internet 3.0.

The IPFS network also needs to address files (content), but completely different from the HTTP protocol in that the addressing service of IPFS no longer relies on centralized services like the DNS network, but It is completely carried out through the decentralized distributed hash table (DHT: Decentralized Hash Table). The network layer of IPFS is LibP2P, so it can provide greater flexibility and fault tolerance. At the same time, IPFS draws on many technologies from peer-to-peer file systems to form a complete set of protocols, including: BitTorrent, Git, SFS, etc.

The implementation principle of IPFS's content addressing method is very simple, which is to perform a hash operation on the content to generate a unique content identification (CID: Content Identity) related to the content. The anti-collision feature of the Hash algorithm ensures the uniqueness of the identification, so this identification is also called a content fingerprint; the certainty of the Hash algorithm ensures that the same content will generate the same identification, so in the same storage network, it can Content is deduplicated to achieve higher storage efficiency.

The goal of IPFS is to build a unified, decentralized storage platform that does not rely on a single entity, which is in line with the idea of ​​​​blockchain. Compared with HTTP, IPFS has many advantages:

These characteristics of IPFS form the basis of Web3.0 data storage. Therefore, these characteristics of IPFS also become the characteristics of Web3.0. The IPFS network has been successfully operating for several years. As a public welfare, open, and open source network, its operation is very successful. However, for commercial operations, due to the lack of incentive layer and the difficulty in coordinating the service guarantee system of distributed nodes, there are still problems. There are many challenges, and these challenges are also what storage-related projects such as Filecoin hope to solve.

Digital identity based on cryptography - Digital Identities

Digital identity is another important technology brought about by the development of blockchain. It may become one of the most important features of Web 3.0. In today's internet, everything from identity theft to click fraud is rife, and it happens because the connection between two computers is not authenticated properly. In a Web 2.0 network, a server can never be sure that the client software accessing it is pretending to be a browser under the control of an identifiable human being. On the other side of the equation, the browser doesn't know about it eitherWhether the server and file being accessed are the files it was intended to access.

However, it is much more difficult to commit fraud and deceit if everything involved in this interaction has a verifiable identity. With digital IDs, each person has a verifiable identity because each identity must be linked to a unique credential. Likewise, organizations have a verifiable identity. As for everything else involved in the interaction between client and server (hardware and software), these things can be tied directly to a unique ID belonging to a person or organization. And, thanks to technologies like zero-knowledge proofs, it’s possible for any party to prove they are authentic without even revealing their identity.

Digital ID enables two important functions of Web 3.0:

The very important reason for this is that user identity authentication and behavior verification are unified, and encryption technology is applied to each user. One message greatly improves security. Of course, these also increase the cost of terminal use, and the truth is always higher than the magic. As computing technology advances, the strength and algorithms of encryption will evolve, and security also relies on users protecting their private keys.

Based on blockchain financial network - Decetralized Finance

So far, we have mentioned two technical foundations: distributed file system and digital identity, both related to blockchain Chain technology related. The importance of blockchain to Web3.0 is self-evident, but its most important contribution lies in its ability to create tokens and maintain the network through carefully designed economic models, including the use of such tokens for governance. The ability to make small payments.

In a blockchain-based Web3.0 network, the way finance operates is very different from traditional finance. Finance is more programmed and changes more quickly and quickly. There is no need for banks and institutions to endorse it. The financial market is also an algorithmic market. Here, there are not only tokens with value storage that can store and transfer high amounts of value, but also small payment capabilities for fast transactions similar to the Lightning Network. Different tokens provide different functions. What is even more exciting is that the entire financial market is completely an algorithmic market and is not controlled by institutions. Therefore, algorithm-based equity trading, lending markets, non-stop real-time trading, insurance, futures, etc. can all be constructed. And continue to innovate.

Regarding the value of information, Web3.0 is completely different from Web2.0. Due to tokenization, the value of information can be directly reflected in transactions, realizing the unification of value flow and information flow. Unlike the free services in Web 2.0, which are full of illusions, service providers actually make profits through advertising and mining the value of users' data in a roundabout way.

NetworkBuilding Trust - Trustless

One might argue that the most important contribution of blockchain is automated trust. This goes beyond the security that blockchain can provide through digital IDs by building a network of trust.

Some blockchains can create "smart contracts," programs that are attached to the blockchain and executed when specific blockchain events are triggered. The important thing about smart contracts is that the program code is the contract.

This makes smart contracts more deterministic than legal contracts. Legal contracts are enforced through legal systems, whose reliability varies from place to place but is never perfect. The outcome of challenging a legal contract is uncertain.

However, smart contracts can be 100% trusted. A simple example of a smart contract is given by the movement of goods in a supply chain. Items are shipped with an RFID tag that reports the location of the item when it is read. Smart contracts can automatically execute payments when goods arrive at a specific location - shipping, warehousing or import duties. Therefore, payments are predictable and can be happened with 100% confidence.

Naturally, smart contracts can be much more complex than this example. They can cover many situations that legal contracts currently cover, reducing the possibility of fraud.

Ⅲ Is blockchain technology really a post-Internet era? What is its manifestation?

Yes, blockchain must be a necessary technology in the post-Internet era.

Specifically reflected in its non-tamperability and the ability to achieve decentralization:

1. On the Internet, value and rights can be transferred.

2. A decentralized system can be built so that multiple parties can trust each other.

The first point is that value and rights can be conveyed on the Internet.

We all know that it is easiest to copy and paste on the Internet, and we can easily transfer information. However, if value is transferred on the Internet, the information may be stolen and tampered with. With blockchain technology, the information we put on the Internet can not be tampered with, and we are not afraid of being stolen. As a result, proof of value and equity can be transmitted on the Internet.

There are too many examples of value transfer. For example, Bitcoin is a digital asset that can be transferred at will through the Internet, and does not require a centralized organization to manage it.

But how to understand the transfer of proof of equity? For example, when we go to handle government affairs, we often encounter that I go through a procedure at a window of a department, and then take the paper procedure and go to the window of the next department. Although we have experienced the Internet for so many years, we still have to go through so many processes and handle various paper documents. Why is this?

This is because technology is now very developed, and it is actually very easy to tamper with some electronic documents. Without the combination of blockchain, it is more difficult to trust the electronic information you submit. Therefore, in order for the window department to know that you are yourself and that you are willing to apply for the application, you often need to bring your ID card and then fill in the information in person on site to ensure that you are applying for it out of your own will. This way nothing goes wrong.

Combining blockchain and face recognition, it can be done. The procedures I completed in one department are put on the blockchain, and the other department only needs to complete the procedures on the blockchain. If you check it online, you will know that I have gone through the relevant preparatory procedures myself, and then I can proceed.

In fact, Chancheng District, Foshan, Guangdong is already exploring the use of blockchain technology to achieve "zero errands" in government affairs. It can handle government affairs without leaving home, which has greatly improved Processing benefits.

Let’s talk about the second point: a decentralized system can be built so that multiple parties can trust each other. Before the emergence of blockchain, it was difficult for multiple entities to collaborate, especially online collaboration. This is why cross-border transfers generally take several days and are expensive, with fees of several percent. Because for cross-border transfers, different banks have different account books and use different systems. Therefore, it is often necessary for the personnel responsible for external clearing and settlement of the two banks to synchronize the account books with each other before the transfer can be successful.

Some people say that if everyone uses one system, then the question becomes, whose system should we use? Other companies don't trust whoever uses it, because whose system often has the authority to modify it, and the operating rights are in the hands of the other party, not to mention issues such as privacy.

But if the system is developed using blockchain, this problem can be solved very well, because everyone uses the same system, and the permissions between each node are consistent, and no one The subject can be changed at will.

In fact, in June 2018, Ant Financial had already used blockchain technology to achieve rapid cross-border remittances. It takes three seconds and the fee is extremely low and can be ignored.

This decentralized solution brought by blockchain establishes a collaborative relationship that is different from previous centralization, solves some insurmountable problems of centralization, and greatly improves efficiency.

If we extend from this direction, think about any company we are in, it will always be upstream or downstream of another company, and it will definitely exchange materials, funds, information, etc. with the other company. A series of interactions etc. Then you will find that many processes are often created for trust. For example, the information sent by the other party needs to be confirmed, and the materials sent by the other party need to be confirmed and checked. Every time you make a new action with the other party, there will be constant questions. Confirmation, feedback. And these are the costs of trust.

But if the blockchain is used, the data generatedAfter that, it is put on the blockchain, and all enterprises upstream and downstream of this supply chain obtain the data. Then a lot of data does not need to be repeatedly confirmed, which can greatly reduce the cost of trust. At the same time, because the data transmitted is credible. Once the data is trusted, the interaction between machines will reduce a lot of trouble in the future. (This is another big topic)

Blockchain technology is widely regarded as an important starting point for achieving a more secure Internet - its advantages mainly come from its technical principles and the current Internet structure. different. In this article we will introduce to you how blockchain can promote network security.

What is blockchain technology?

Blockchain technology is a decentralized distributed ledger system. You can put any digital assets into the blockchain, regardless of any industry. It uses a series of time-stamped immutable records to save information, managed by a cluster of computers. Different transactions can be tracked through these records, which are separated by blocks and connected by cryptographic chains. At the same time, the data does not belong to a certain computer or an individual, but is jointly owned by multiple users within the entire system.

Once the information is confirmed, the encoded data cannot be changed and will become a permanent block that is added to the chain formed by other blocks that have been verified. Initially this technology was designed for cryptocurrencies, but now we can see that blockchain technology has great potential in many areas, especially cybersecurity, as it can be used to prevent cyber attacks, data leaks, identity theft or Malicious transactions, keeping data private and secure.

As a lower-level technology, blockchain can provide beneficial solutions for different industries. Its main features are:

Blockchain has a democratized network with no central authority. It is public domain, so no single organization can enter the blockchain system to manipulate any information.

Blockchain is a decentralized system that does not belong to any one entity. Data in the blockchain system can be stored encrypted.

Anything stored in the blockchain is immutable, preventing human tampering or manipulation of the information. For example, with blockchain, it is possible to hold a completely transparent election with immediate results. People can vote at home, and the results can be counted immediately.

Blockchain is transparent - anything built and stored in the blockchain is publicly accessible. The data stored inside can also be tracked, creating a higher standard of accountability for those who use the system.

How does blockchain technology promote network security?

Internet of Things and Edge Computing

With the development of Internet of Things and edge computing, more and more data Distributed across edge computing and storage devices for real-time, on-demandAccess is required, that is, data is processed and stored closer to the data source. Blockchain provides a secure solution for IoT and Industrial IoT through tighter authentication, improved data attributes and flows, and more advanced record management systems.

In terms of IoT devices, blockchain technology, based on its decentralized architecture, can provide security for remote IoT devices and protect them from hacker attacks. Smart contracts can provide secure verification for transactions in a blockchain environment, and blockchain can be used to manage IoT activities.

Data access control

Because one of the original goals of blockchain was to enable public access, it has no access controls or restrictions. However, various industries now use private blockchain systems to ensure data confidentiality and secure access control. The blockchain’s full encryption ensures that data – whether part or all of it – cannot be accessed by outsiders, especially when it is being transferred.

DDoS Attack

The target of a Distributed Denial of Service (DDoS) attack is usually a server that is attacked by multiple infected computer systems, causing the system to fail through denial of service. slow down, eventually causing the system to overload or crash. If blockchain is integrated into a security system, the target computer, server, or network becomes part of a decentralized system that protects these machines from attacks.

Personal communication

By using a platform based on blockchain technology for communication, enterprises can obtain higher security, and this technology can resist malicious attacks. Whether in personal, business or highly confidential communications, consumers can gain the confidentiality of communications without fear of cyber attacks. Blockchain can handle public key infrastructure (PKI) better than ordinary encryption applications, so many companies now want to develop blockchain private communication applications.

Public Key Infrastructure

There is an increased focus on securing computers and online credentials, and blockchain technology can help in this regard. PKI relies on third-party certification authorities to secure communications applications, emails, and websites. These issuing authorities, which issue, revoke or store key pairs, are often targeted by hackers, who often use fake identities to try to access encrypted communications. When these keys are encoded on the blockchain, it minimizes the possibility of generating false keys or identity theft because the identity of the legitimate account holder is already verified on the application, making any intrusion, spoofing, or identity theft Thefts are instantly identifiable.

Domain Name System

Using the blockchain method to store the Domain Name System (DNS) can comprehensively improve security. Because it is no longer a single, risky target, it can prevent malicious activities by hackers from bringing down DNS service providers.

Blockchain, the future of network security

As we continue to deepen our understanding of blockchain, more and more people are investing in the application and research and development of blockchain technology, and this technology is slowly maturing. In the past two years, the application of blockchain in different industry scenarios has increased, as well as the country’s policy guidance on blockchain technology. Blockchain has changed dramatically and is no longer synonymous with cryptocurrency.

Blockchain technology may be born of cryptocurrency, but its value is by no means limited to cryptocurrency. Blockchain is a safe and reliable technology that, once integrated into mainstream security measures, can bring many practical benefits to advancing cybersecurity.

As hackers continue to create new and more sophisticated ways to steal and attack data, the threat to network security is intensifying, and blockchain technology is likely to become the forefront of network security in the next few years. To a certain extent, today’s blockchain is the future of network security.

My understanding is that blockchain is a technology, and the Internet is just a carrier or a communication channel for information integration. It should not be a post-Internet era.

Blockchain can be truly fair and open, and what has happened will not be tampered with when recorded.

Blockchain is decentralized, cannot be cracked, and uniqueness is irreplaceable

IV There are many blockchain applications now. What kind of blockchain is considered a good one? Where can I clearly understand the application?

If you want to understand the application of blockchain, you can refer to many books and opinions, including "Blockchain in Pictures" and "Blockchain: Reshaping the Economy and the World" "New Economic Blueprint and Introduction", as well as articles on Binance Community, including a detailed understanding of the Binance Community platform, which is extremely powerful.

1. What is blockchain

Blockchain, as the name suggests, is composed of blocks and chains. It is a distributed data storage , point-to-point transmission, consensus mechanism, encryption algorithm and other new application models of computer technology. It is a chained data structure that combines data blocks in a sequential manner in chronological order, and is cryptographically guaranteed to be an untamperable, unforgeable, safe and trustworthy distributed ledger.

In 2008, Satoshi Nakamoto first proposed the concept of blockchain and encrypted digital currency in his paper "Bitcoin: A Peer-to-Peer Electronic Cash System". Starting from Bitcoin, blockchain has become the underlying technology of various digital currencies.

2. The working principle of blockchain:

1. Basic concepts include:
(1) Transaction: one operation will change the ledger status once , such as adding a record;
(2) Block: records transactions and status data that occurred within a specified time, which is a consensus and preservation of the current ledger status;
(3) Chain ( Chain): It is composed of blocks connected in chronological order.Log records of status changes.
Understanding the working concept of blockchain, it is not difficult to understand its working principle. Suppose there is a distributed data record book. This record book only allows additions, deletions and changes. Its structure is composed of individual data records. A linear chain formed by "blocks" connected in series (this is also the origin of the name "blockchain"). To add new data, it must be placed in a new block. The maintenance node can propose a new block. However, a certain consensus mechanism must be used to reach agreement on the final selected block.

2. Take Bitcoin as an example to see how the blockchain works.

Bitcoin blocks are divided into two parts: block header and block body.

3. Core advantages and characteristics of blockchain

1. Decentralization
Block The processes of verification, accounting, storage, maintenance and transmission of chain data are all based on the distributed system structure. There is no centralized hardware or management organization. The rights and obligations of any node are equal. The data blocks in the system are composed of Nodes with maintenance functions in the entire system are jointly maintained.
2. Open and transparent
The system is open. In addition to the private information of the transaction parties being encrypted, the blockchain data is open to everyone, and anyone can query the blockchain through the public interface. Data and development related applications, so the entire system information is highly transparent.
3. Security
The blockchain adopts consensus-based specifications and protocols (such as a set of open and transparent algorithms) to enable all nodes in the entire system to exchange data freely and securely in a trustless environment. , so that trust in "people" is changed to trust in machines, and any human intervention has no effect.
4. Information cannot be tampered
Once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% of the nodes in the system (almost impossible) can be controlled at the same time, otherwise Modifications to the database on a single node are invalid, so the data stability and reliability of the blockchain are extremely high.
5. Anonymity
Since the exchange between nodes follows a fixed algorithm, the data interaction does not require trust (the program rules in the blockchain will judge whether the activity is valid by itself), so the counterparty does not need to Making the other party trust you by disclosing your identity is very helpful for the accumulation of credit.

4. Classification of Blockchains

Currently, the most mainstream classification of Blockchains is to divide Blockchains into Public Blockchains based on different participants. ), Private Blockchain and Consortium Blockchain.

1. Public chain: Anyone can participate in the use and maintenance, and can obtain effective confirmation of the blockchain. The public chain is the earliest blockchain and the most widely used blockchain at present. , a typical example isIn the Bitcoin blockchain, information is completely public.

If a permission mechanism is introduced, it will include private chain and alliance chain.
2. Private chain: A company or individual only uses blockchain technology and has exclusive write permission to the blockchain, and the information is not made public. At present, conservative giants (traditional finance) all want to experiment with private blockchains, and the application products of private blockchains are still being explored.
3. Consortium chain: It is a blockchain between the public chain and the virtual chain, jointly controlled by multiple organizations. The use of this chain is managed with authority and can be controlled by managers and also based on The manager's wishes are open to others.
In addition, according to the different usage scenarios and purposes of blockchain, it is divided into currency chains for the purpose of digital currency, property rights chains for the purpose of recording property rights, crowdfunding chains for the purpose of crowdfunding, etc. .

5. Analysis of specific application scenarios of blockchain

1. Information anti-counterfeiting

On May 28, Tencent CEO Ma Huateng spoke at the Guiyang Digital Expo The problem of Moutai anti-counterfeiting has been raised: the anti-counterfeiting method based on cloud-based comprehensive blockchain technology will be much more efficient than traditional anti-counterfeiting methods. In future anti-counterfeiting verification scenarios, users may only need to perform a simple scan with their mobile phone to obtain a large amount of complete information based on different dimensions.

Take Moutai as an example:

Distillery address, production workshop, operating employees, inspectors, factory time, transportation vehicle information and driver information,

The vintage source of raw materials for wine, raw material suppliers, storage warehouse numbers, raw material transportation vehicles and driver information,

All information can be accurately traced, permanently recorded and cannot be tampered with.

The authenticity can be easily verified based on the above information.

2. Food safety issues

As early as November last year, Walmart had cooperated with IBM to ensure food safety by using blockchain technology to track food sources. safety and increase the circulation of food to reduce costs. For large supermarkets such as Wal-Mart, when food safety problems occurred in the past, it took several days to investigate the source of the problematic food. After using this technology, only one piece of information about the product is required. It can accurately trace the source of important information such as food origin, inspectors, suppliers, logistics and transportation, and quickly detect problems within a few minutes. Currently, products tracked using blockchain include packaging products in the United States and pork in China.

3. Information Security

Blockchain technology is promoting a revolution in information security technology. Three major security threats: man-in-the-middle attack, data tampering, and DDoS

(1) Identity protection

PKI is a common public key encryption used in various communication applications such as email, messaging applications, and websites. technology. However, since most PKI implementations rely on a centralized trusted third-party certification authority (CA) to issue, activate and store user certificates, hackers can attack PKI to fake user identities or crack encrypted information.

CertCoin is the first blockchain PKI implementation, coming from MIT, which removes the centralized certification center and uses the blockchain as a distributed ledger of domain names and public keys.

Pomcor Company: Blockchain PKI implementation path: retain the certification center and use the blockchain to store hash values ​​of issued and activated certificates. Users can verify the authenticity of certificates through decentralized and transparent sources, while also improving network access performance through local authentication of keys and signatures based on blockchain copies.

(2) Data integrity protection

GuardTime has developed a keyless signature architecture (KSI) based on blockchain technology to replace key-based data authentication technology. KSI stores hashes of the original data and files on the blockchain, runs hashing algorithms to verify other copies, and compares the results with the data stored on the blockchain. Any tampering with the data will be quickly detected because the original hash table is stored on millions of nodes.

(3) Protection of critical infrastructure

The "Achilles' heel" of the Internet, DDoS has entered the TB era, and DDoS is still the easiest way for hackers to defeat large targets at low cost. As a weapon, DNS services are the primary target for hackers to carry out large-scale damage, but blockchain technology is expected to fundamentally solve it.

The distributed storage of blockchain makes hacker attacks lose focus. Nebulis is developing a distributed DNS system using the Ethereum blockchain and the InterPlanetary Internet File System (IPFS, a distributed alternative to HTTP product) to register and resolve domain names. The biggest weakness of DNS is caching. Caching makes DDoS attacks possible and is also the bane of centralized governments censoring social networks and manipulating DNS registrations. A highly transparent, distributed DNS system can effectively prevent any entity, including the government, from manipulating records.

IV. Financial Industry

(1) Digital Currency: Improving the convenience of currency issuance and use

For example, foreign Bitcoin and Ethereum, our country currently There are Nuo Compao and so on.

From the use of physical transactions, to physical currency and credit currency, to the rise of the Bitcoin network, more people are aware of the distributed ledger blockchain technology behind it, and gradually outside of digital currency applied in many scenarios.

(2) Cross-border payment and settlement: realize point-to-point transactions and reduce intermediate costs

Transfer and payment. At present, the most mature application of blockchain technology is payment and transfer. Blockchain technology can avoid complicated systems, save the process of inter-bank reconciliation and review, and speed up settlement; using virtual currency does not require the intervention of a clearing house, reducing transaction fee. The clearing procedures of each country are different. It takes 2 or 3 days for a single remittance to arrive, which is inefficient and accounts for a large proportion of funds in transit. No longer going through a third party, point-to-point payment is formed through blockchain technology. Eliminating the need for third-party institutions, you can make payments throughout the day, receive money in real time, quickly withdraw cash, and reduce hidden costs, helping to avoid financial risks.. It is timely and convenient.

(3) Bills and supply chain financial business: reduce human intervention, reduce costs and operational risks

Point-to-point value transfer, physical bills or central system for control and verification; intermediary will be eliminated and human intervention reduced. Improved efficiency, smoother financing channels, lower risks, and benefits for all parties.

(4) Securities issuance and trading: realize quasi-real-time asset transfer and accelerate transaction clearing speed

The application of blockchain technology can make the securities trading process simpler, more transparent and faster , Reduce IT systems with repetitive functions and improve the efficiency of market operations. For stocks, blockchain can eliminate paper and pen or spreadsheet records, reduce human errors in transactions, and improve the transparency and traceability of trading platforms. Citi and Nasdaq collaborate to advance blockchain applications.

(5) Customer credit reporting and anti-fraud: reduce legal compliance costs and prevent financial crimes

Customer information and transaction records recorded in the blockchain help banks identify Abnormal transactions and effectively prevent fraud. The technical characteristics of blockchain can change the existing credit reporting system. When banks perform "know your customer" (KYC), the data of customers with bad records will be stored in the blockchain.

Equity crowdfunding: Equity crowdfunding based on blockchain technology can achieve decentralized trust and investors’ returns are guaranteed.

5. Supply chain management

Distributed ledger system, participants track the ownership of assets throughout the process, and can be used to track auto parts when moving between countries and factories.

Toyota is developing blockchain technology solutions for its core parts supply chain operations. Using a large amount of data helps Toyota more efficiently ensure the accuracy of recorded data and can also help manage the supply chain. At the same time, the blockchain supply chain can control warranty, repair goods-related costs and specifications through smart contracts, and transactions throughout the product life cycle are irrevocable.

The shipping industry’s first public solution, deployed by Maritime Transport International (MTI), uses blockchain supply chain technology to share Verified Gross Mass (VGM) information for shipping containers. Information about container VGM is important to ensure ships are properly stowed and to prevent accidents at sea and in ports. VGM data is stored on the blockchain supply chain, providing a permanent record for port officials, shipping companies, shippers and cargo owners. This replaces cumbersome logs, spreadsheets, data brokers and private databases.

Logistics Integrity System Wagonbang Wagonbang launched a blockchain-based financial solution for logistics enterprises, aiming to provide enterprises with reliable financial services. It can not only help drivers solve the problem of loan difficulty, but also change the current situation of lack of integrity in the industry and help build a logistics integrity system. Help build the identity chain of logistics companies and create a trusted data ecosystem for logistics companies. Using a transparent, supervisory, and traceable algorithm model, we screen reliable companies that need financial support and provide them with financial services. On the other hand, at the technical level, various law enforcement agenciesLink up and jointly punish dishonest companies.

6. Government management

(1) Election

Based on the characteristics of blockchain technology and considering the shortcomings of current election technology, we will build an open source , Blockchain applications for elections, voting and lottery, we call it ElectionChain. We hope to optimize election and voting technology to make voting more open and transparent, reduce human manipulation, and allow voters to verify their election results.

Including identity authentication, multi-chain system, flash investment protocol, consensus algorithm EDPOS, privacy protection, voting mechanism design, decentralized ELC rental market, storage solutions, smart contracts, etc.

(2) Government services

Aiming to realize an e-government digital ecosystem based on blockchain technology and provide citizens with government services and an automated mechanism for the business of various government departments, it must be All areas of national government affairs are combined to form a common information space, including government agencies, economic data, financial transactions and social fields. This ecosystem should also include registries and corresponding software for building smart contract-based applications and platforms for government agencies, businesses and public users.

IV Application aspects of blockchain

The main application scope of blockchain includes: digital currency, transaction settlement of financial assets, digital government affairs, certificate deposit and anti-counterfeiting data services and other fields. Blockchain is a database technology that links data blocks in an orderly manner. Each block is responsible for recording a file data and encrypting it to ensure that the data cannot be modified or forged.

Blockchain is essentially a distributed database system that uses cryptography technology for multi-party participation, joint maintenance, and continuous growth. It is also called a distributed shared ledger. Each page in the shared ledger is a block, and each block is filled with transaction records. The anonymity, decentralization, openness, transparency, and non-tamperability of blockchain technology make it highly favored by enterprises and has gained More extensive application attempts.

Blockchain application scope 1. Financial field

Blockchain can provide a trust mechanism and has the potential to change the financial infrastructure. Various financial assets such as equity, bonds, bills, warehouse receipts, fund shares, etc. It can be integrated into the blockchain technology system and become a digital asset on the chain, which can be stored, transferred and traded on the blockchain.

The decentralization of blockchain technology can reduce transaction costs and make financial transactions more convenient, intuitive and secure. The combination of blockchain technology and the financial industry will inevitably create more and more business models, service scenarios, business processes and financial products, thereby bringing more impact to the development of financial markets, financial institutions, financial services and financial formats. . With the improvement of blockchain technology and the combination of blockchain technology with other financial technologies, blockchain technology will gradually adapt to the application of large-scale financial scenarios.

2. Public service field

Traditional public services rely on limited data dimensions, and the information obtained may not be comprehensive and have certain limitations.Certain hysteresis. The non-tamperable nature of the blockchain makes the digital certification on the chain highly credible. It can be used to establish new authentication mechanisms in the fields of property rights, notarization and public welfare, and improve the management level of public services.

Relevant information in the public welfare process, such as donation projects, fundraising details, fund flows, recipient feedback, etc., can be stored on the blockchain to meet the privacy protection of project participants and other relevant laws and regulations. Under the premise of requirements, public disclosure will be made conditionally to facilitate public and social supervision.

3. Information security field

Using the traceability and non-tampering characteristics of blockchain, we can ensure the authenticity of data sources and ensure the non-forgery of data. Blockchain technology will fundamentally change information Security issues of the propagation path.

Blockchain is reflected in the following three points in the field of information security:

User identity authentication protects data integrity and effectively prevents DDoS attacks

The distributed storage architecture of blockchain will make Hackers are at a loss as to what to do. Some companies have begun to develop a distributed Internet domain name system based on blockchain to eliminate the root cause of the current DNS registration shortcomings and make the network system cleaner and more transparent.

4. Internet of Things field

Blockchain + Internet of Things can allow each device on the Internet of Things to operate independently, and the information generated by the entire network can be protected through smart contracts in the blockchain.

Security: Traditional IoT devices are highly vulnerable to attacks, data loss and maintenance costs are high. Typical information security risk issues for IoT devices include low firmware versions, lack of security patches, permission loopholes, too many device network ports, and unencrypted information transmission. The blockchain's consensus mechanism for network-wide node verification, asymmetric encryption technology and distributed data storage will significantly reduce the risk of hacker attacks.

Trustability: The traditional Internet of Things is managed and controlled by a centralized cloud server. Due to the security of the device and the opacity of the centralized server, it is difficult to effectively protect user privacy data. The blockchain is a distributed account book. Each block is interconnected and has its own independent working ability, ensuring that the information on the chain will not be tampered with at will. Distributed ledgers can therefore provide trust, ownership records, transparency and communication support for the Internet of Things.

Effectiveness: Limited by cloud services and maintenance costs, the Internet of Things is difficult to achieve large-scale commercial use. The traditional Internet of Things realizes communication between things through centralized cloud servers. The disadvantage of this model is that as the number of access devices increases, the server faces more load, requiring enterprises to invest a lot of money to maintain the normal operation of the IoT system.

Blockchain technology can directly realize point-to-point transactions, omitting the labor expenditure of other intermediaries or personnel, which can effectively reduce the costs incurred by third-party services and maximize benefits.

5. Supply chain field

The supply chain consists of many participating entities, with a large amount of interaction and collaboration. Information is discretely stored in their own systems, lacking transparency. The lack of smooth information makes it difficult for all participants to accuratelyAccurately understand the real-time status and existing problems of related matters, which affects the collaborative efficiency of the supply chain. When disputes arise between parties, it is time-consuming and laborious to provide evidence and pursue accountability.

Blockchain can make data open and transparent among various entities, thereby forming a complete, smooth, and non-tamperable information flow throughout the entire supply chain. This can ensure that all entities promptly discover problems arising during the operation of the supply chain system and find targeted solutions, thus improving the overall efficiency of supply chain management.

6. Automotive Industry

Last year announced a partnership using blockchain to build a proof of concept to streamline the car rental process and build it into a “click, sign up, and drive” process. Future customers choose what they want The rented car enters the public ledger of the blockchain; then, sitting in the driver's seat, the customer signs the rental agreement and insurance policy, and the blockchain updates the information simultaneously. This is not an imagination, for car sales and car registration Said, this type of process may also develop into reality.

7. Stock Trading

For many years, many companies have worked to make the process of buying, selling, and trading stocks easy. Emerging Blockchain Chain startups believe that blockchain technology can make this process more secure and automated than any previous solution. At the same time, blockchain startup Chain is working with Nasdaq to enable private companies through blockchain. Equity transfer

8. Government management

Government information, project bidding and other information are open and transparent. Government work is usually subject to public attention and supervision. Since blockchain technology can ensure the transparency and immutability of information, it is very important to the government. The implementation of transparent management plays a great role. There is a certain degree of information opacity in government project bidding, and enterprises also have the risk of information leakage during the sealed bidding process. Blockchain can ensure that bidding information cannot be tampered with and can ensure the transparency of information nature, forming a common trust among competitors who do not trust each other. It can also arrange subsequent smart contracts through the blockchain to ensure the construction progress of the project and prevent the growth of corruption to a certain extent.

There are many more applications of blockchain technology, and this is just a fulcrum of blockchain applications. In the future, blockchain technology will be applied everywhere

VI Domain Name System and Blockchain

In this centralized domain name registration management method, there is a risk of abuse of power by the domain name management agency. The registration management operating agency only controls the registered domain name information database under its jurisdiction. Once the registration management agency functions The availability of some domain names will be threatened if they are destroyed or misoperated by domain name management agency personnel. For example, domain name data is tampered with or deleted, causing the domain name to fail to resolve normally. In addition, the registrar controls the platform for domain name registration and management. If registered Intentional or unintentional modification of domain name data submitted by registrants by service agencies will also lead to domain name security issues. The opaqueness of domain name registration management provides room for abuse of power. Even if the management agency's management methods are not standardized, others will not be able to learn about its irregularities. Standardize behavior.

Therefore, in the current domain name registration management system, the domain name data associated with the domain name is completely controlled and maintained by the domain name registration management operation agency and registrar service agency to which the domain name belongs. There is a single point of attack caused by the registration management operation agency. Risk of data being altered or deleted due to malfunction or staff misoperation. In addition, the opaqueness of the domain name registration management process brings uncontrollable factors to the standardized registration management of domain names.

The emergence of blockchain technology provides a solution for decentralized domain name registration management. Blockchain is a distributed ledger technology that does not rely on trusted central nodes. It uses cryptographically strict transaction verification rules and rigorous chained data structures to ensure that the data in the ledger cannot be easily tampered with. At the same time, it uses consensus algorithms to Account book data sharing is realized in a peer-to-peer network environment. Combining blockchain technology to design decentralized solutions to security issues existing in the domain name registration and management process, using blockchain's distributed account books to store domain name data, replacing the domain name database maintained by the registration management operating agency; developing domain names based on consensus among all parties The rules of registration management are written into smart contracts, and the non-tamperable and traceable characteristics of the blockchain are used to ensure the transparency of the domain name registration management process, thereby preventing the risk of power abuse contained in the centralized domain name registration management scheme.

Since this invention mainly studies the use of blockchain to reconstruct the domain name registration management system, the background technology summarizes the research status of distributed domain name registration management services combined with blockchain technology.

Namecoin[1] is the first project to combine domain name services with blockchain, using blockchain to build a decentralized domain name system. Namecoin supports operations such as registering a name under a specific namespace, updating data bound to the name, transferring the name, and resetting the name expiration time. The registered name in Namecoin adopts a two-stage submission method. First, the hash value of the name is submitted to reserve the name, and then the real registered name is submitted. This method can prevent the name registration operation from being registered before it is confirmed. Namecoin contains a ".bit" namespace, which is similar to a top-level domain. The names registered by users are all under this namespace. However, ".bit" is excluded from the ICANN domain name system, and its registered domain name can only be resolved through a special browser provided by Namecoin. Muneeb et al. [2] proposed Blockstack based on Namecoin development and operation and maintenance experience, using technologies such as layering and virtual chains to migrate domain name services to the Bitcoin system. On Blockstack, users adopt the two-step process of "booking and registering" to obtain name ownership. Unlike Namecoin, the cost of registering different names is not fixed. Blockstack uses a price function to price based on the length and characters of the name to prevent short domain names and meaningful domain names from being registered in large numbers. Ethereum Name Service (Ethereum Name Service (ENS) [3] is a distributed, open and extensible naming system based on the Ethereum blockchain. Its main function is to map human-readable names to machine-readable identifiers. ENS consists of two parts: registration and parsing. Registration is completed by a smart contract that maintains a list of all domain names and subdomains and stores three key pieces of information: the domain name owner, the domain name resolver, and the cache time of the domain name record. The domain owner can be an external user or a smart contract, and the owner can set the name resolver and cache lifetime, transfer domain ownership to another address, and change ownership of subdomains. Handshake[4] is an open source blockchain domain name project established by Joseph Poon, the founder of the Bitcoin Lightning Network, in 2018. It focuses on top-level domain name registration, transactions, resolution and domain name ownership certification, aiming to change the current centralized governance of domain names. pattern. The goal of Handshake is to maintain root zone files in a distributed manner and replace the root server. Handshake is compatible with existing DNS. The system initially includes all domain names in the ICANN root zone and the top 100,000 domain names ranked by Alexa. These domain names are called reserved domain names. Handshake uses DNSSEC certification to migrate reserved domain name owners into the system, thus bypassing domain name auctions. BlockDNS[5] is also a blockchain-based name system designed to solve the centralization problem of DNS and the authenticity of data. BlockDNS allows users to apply for a second-level domain name. The domain name is bound to the public key of the domain name owner. The domain name owner can transfer, renew the domain name and update the domain name data.

It can be seen from the above that no one in the existing technology has proposed to realize the decentralization of domain name registration data and the transparency and standardization of domain name registration management through the domain name registration management chain.