How to understand Wang Xin's blockchain

1.

If you want to understand the application of blockchain, you can refer to many books and opinions, such as illustrated blockchain, blockchain: reshaping the economy and the world, blueprint and guide of new economy, and articles of coin'an community, including a detailed understanding of the platform of coin'an community, with great strength

As the name suggests, blockchain is composed of block and chain. It is a new application mode of computer technology such as distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and so on. It is a kind of chain data structure that combines data blocks in order according to the time sequence, and it is a secure and reliable distributed account book that can not be tampered with and forged by means of cryptography

in 2008, in his paper bitcoin: a peer-to-peer e-cash system published by Nakamoto, he first proposed the idea of blockchain and encrypted digital currency. Starting from bitcoin, blockchain has become the underlying technology of various digital currencies

Second, the working principle of blockchain:

1. The basic concepts include: (1) transaction: one operation will change the account status once, such as adding a record 2) Block: records the transaction and status data within a specified time, which is a consensus and preservation of the current account status 3) Chain: it is composed of a series of blocks in chronological order, which is the log record of the whole state change. If you understand the working concept of blockchain, it is not difficult to understand its working principle. Suppose there is a distributed data logbook, which can only be added, not deleted or changed. Its structure is a linear chain formed by a series of "blocks" (which is also the source of the name of "blockchain"), and new data must be put into a new block to be added, The maintenance node can propose a new block, but it must go through a certain consensus mechanism to reach an agreement on the final selected block

2. Take bitcoin as an example to see the working principle of blockchain

the block of bitcoin is divided into block head and block body

Core advantages and characteristics of blockchain

1. The verification, accounting, storage, maintenance and transmission of decentralized blockchain data are all based on distributed system structure. There is no centralized hardware or management organization, and the rights and obligations of any node are equal, The data blocks in the system are jointly maintained by the nodes with maintenance function in the whole system. 2. The open and transparent system is open. In addition to the private information of all parties to the transaction is encrypted, the data of the blockchain is open to all. Anyone can query the blockchain data and develop related applications through the open interface, so the information of the whole system is highly transparent. 3. Security blockchain uses consensus based specifications and Protocols (such as a set of open and transparent algorithms) to enable all nodes in the whole system to exchange data freely and safely in a de trusted environment, so that the trust in "people" is changed into the trust in machines, and any human intervention does not work. 4. Information cannot be tampered with. Once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% (almost impossible) nodes in the system can be controlled at the same time, the modification of the database on a single node is invalid. Therefore, the data stability and reliability of the blockchain are extremely high. 5. Anonymity because the exchange between nodes follows a fixed algorithm, and its data interaction does not need trust (the program rules in the blockchain will judge whether the activity is effective or not). Therefore, the counterparties do not need to let the counterparties generate their own trust by disclosing their identities, which is very helpful for credit accumulation

At present, the most popular classification of blockchain is to divide blockchain into public blockchain, private blockchain and consortium blockchain according to different participants

1. Public chain: anyone can participate in the use and maintenance, and can obtain the effective confirmation of the blockchain. Public chain is the earliest blockchain and the most widely used blockchain at present, such as bitcoin blockchain. The information is completely public

if the licensing mechanism is introced, it includes private chain and alliance chain. 2. Private chain: a company or indivial only uses the blockchain technology, enjoys the exclusive write permission of the blockchain, and does not disclose the information. At present, conservative giants (traditional finance) want to experiment with private blockchain, and the application procts of private blockchain are still groping. 3. Alliance chain: it is a blockchain between the public chain and the existing chain, which is jointly controlled by multiple organizations. The use of the chain is managed with authority, which can be controlled by the manager, and also open to others according to the manager's wishes. In addition, according to the different use scenarios and purposes of blockchain, it can be divided into currency chain for the purpose of digital currency, property chain for the purpose of recording property rights, and crowdfunding chain for the purpose of crowdfunding

On May 28, Ma Huateng, CEO of Tencent, proposed the anti-counterfeiting method based on cloud integrated blockchain technology, which is far more efficient than traditional anti-counterfeiting methods. The future anti-counterfeiting verification scenario may only require users to use their mobile phones for simple scanning, and a large number of complete information based on different dimensions can be obtained

take Maotai liquor as an example:

distillery address, proction workshop, operation staff, inspector, delivery time, transportation vehicle information and driver information,

liquor year, raw material source, raw material supplier, storage warehouse number, raw material transportation vehicle and driver information,

all information can be accurately traced, permanently recorded and tampered with

the above information can be easily verified

2. Food safety issues as early as last November, Wal Mart has cooperated with IBM to track the source of food by using blockchain technology, so as to ensure the safety of food and increase the circulation of food to rece costs. For Wal Mart and other large supermarkets, it took a few days to investigate the source of problem food, After using this technology, only one item of proct information is needed to achieve accurate traceability, and important information such as food origin, inspector, supplier, logistics and transportation can quickly find problems in a few minutes. Currently, procts tracked by blockchain include packaging procts from the United States and pork from China

3. Information security

blockchain technology is promoting an information security technology revolution. (1) identity protection PKI is a common public key encryption technology in e-mail, message application, website and other communication applications. However, since the implementation of most PKI, the centralized trusted third party certification authority (CA) is used to issue, activate and store user certificates. Hackers can attack PKI to fake user identity or crack encrypted information

certcoin is the first PKI implementation of blockchain, which comes from MIT, removes the centralized authentication center, and uses blockchain as a distributed ledger for domain name and public key

pomcor company: blockchain PKI implementation path: keep the authentication center, and use blockchain to store the hash value of issued and activated certificates. Users can verify the authenticity of certificates through decentralized and transparent sources, and can also improve the network access performance through local authentication of secret key and signature based on blockchain

(2) data integrity protection

guardtime developed a secret key free signature architecture (Ksi) based on blockchain technology to replace the secret key based data authentication technology. Ksi stores the hash table of the original data and files on the blockchain, runs the hash algorithm to verify other copies, and compares the results with the data stored in the blockchain. Any data tampering will be found quickly because the original hash table is stored in millions of nodes

(3) key infrastructure protection

the "Achilles heel" of the Internet, DDoS has entered the TB era, DDoS is still the simplest weapon for hackers to bring down the big target with low cost, DNS service is the primary target for hackers to carry out large-scale destruction, but blockchain technology is expected to fundamentally solve the problem

The distributed storage of

blockchain makes hacker attacks lose focus. Nebulis is developing a distributed DNS system, which uses Ethereum blockchain and interstellar Internet file system (IPFs, the distributed substitute of HTTP) to register and resolve domain names. The biggest weakness of DNS is caching, which makes DDoS attacks possible. It is also the bane of the centralized government's censorship of social networks and manipulation of DNS registration. A highly transparent and distributed DNS system can effectively prevent any entity, including the government, from arbitrarily manipulating records

(1) digital currency: improve the convenience of currency issuance and use, such as bitcoin and Ethernet in foreign countries, and guorenbao in China

from the use of physical transactions, to physical currency and credit currency, and then to the rise of bitcoin network, more and more people are aware of the distributed ledger blockchain technology behind it, and graally apply it in many scenarios other than digital currency

(2) cross border payment and settlement: realize point-to-point transaction, rece intermediate fees

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 accelerate the settlement speed; virtual currency can rece transaction costs without the intervention of clearing house. Different countries have different clearing proceres. It takes two or three days for a single remittance to arrive, which is inefficient and accounts for a large proportion of funds in transit. No longer through the third party, through the blockchain technology to form point-to-point payment. By eliminating the link of the third-party institutions, we can make full day payment, real-time payment, withdraw cash quickly and rece the hidden cost, which helps to avoid the capital risk. It is timely and convenient

(3) bills and supply chain financial business: rece human intervention, rece costs and operational risks

value transfer between point-to-point, control and verify physical bills or central system; Intermediaries will be eliminated and human intervention reced. With the improvement of efficiency, financing channels are more unblocked, risks are lower, and multiple parties benefit

(4) securities issuance and Trading: realize quasi real-time asset transfer, accelerate the speed of transaction clearing

the application of blockchain technology can make the process of securities trading more concise, transparent and fast, rece the plication of IT system, and improve the efficiency of market operation. For stocks, blockchain can eliminate paper and pen or electronic form records, rece human errors in trading, and improve the transparency and traceability of trading platform. Citigroup and Nasdaq cooperate to promote blockchain applications

(5) customer credit investigation and anti fraud: rece the cost of legal compliance, prevent financial crimes

the 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 reference system, and store the data of customers with bad records in the blockchain when the bank concts "know your customer" (KYC)

equity crowdfunding:

2. Blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. The so-called consensus mechanism is a mathematical algorithm to establish trust and obtain interests between different nodes in the blockchain system
blockchain is an important concept of bitcoin, which is essentially a decentralized database and the underlying technology of bitcoin. Blockchain is a series of data blocks generated by cryptography. Each data block contains the information of a bitcoin network transaction, which is used to verify the validity of the information (anti-counterfeiting) and generate the next block
let's talk about the social or economic significance of blockchain. In fact, many of the previous technologies were devoted to "proctivity". For example, artificial intelligence is a kind of progress in proctivity. The blockchain, which has greatly improved the proction relations, is committed to the proction relations. So why do you say that
because the so-called proction relationship is actually how to do business between people and business partners. And these things, originally, are in the cognitive process between people, and there is no special program to program or quantify it
for example, if you and I are good friends now, we can do business. If someone stirs up our relationship and we are not good friends, we will not do business. Even if we can make money in business, we will not do business because there is no trust between us
as for blockchain, it is actually because the data is authenticated by all nodes and backed up at the same time, so my data is as real as possible and can't be tampered with. In this case, if you believe my data, you can make a program on this basis, and then use the data to make what kind of business contract, what kind of service, what kind of service, and what kind of service, what kind of service, what kind of service, what kind of service, what kind of service, what kind of service, what kind of service, etc This "proction relationship" of commercial cooperation is programmed. In this way, we believe in the data and the program compiled by the algorithm. Because you believe in the data and the program, you can develop all kinds of apps in the program. These apps are the proction relations and what business to do. This is: blockchain is actually a reconstruction of "proction relationship".

3.

Blockchain is a term in the field of information technology. In essence, it is a shared database. The data or information stored in it is characterized by "unforgeability", "trace in the whole process", "traceability", "openness and transparency" and "collective maintenance". Based on these characteristics, blockchain technology has laid a solid "trust" foundation, created a reliable "cooperation" mechanism, and has broad application prospects

on January 10, 2019, the state Internet Information Office issued the regulations on the management of blockchain information services. In October 24, 2019, ring the eighteenth collective learning of the Central Political Bureau, general secretary Xi Jinping stressed that "block chain as an important breakthrough in core technology and independent innovation", "accelerating the development of block chain technology and instrial innovation". "Blockchain" has entered the public field of vision and become the focus of social attention

on December 2, 2019, the word was selected into the top ten catchwords of "biting words" in 2019

extended data:

Application of blockchain Finance:

since 2016, the major financial giants have also carried out blockchain innovation projects to explore the possibility of applying blockchain Technology in various financial scenarios. In particular, Puyin group took the lead in creating a "blockchain +" standard digital currency

standard digital currency refers to the process of assets identification, evaluation, right confirmation and insurance completed by a third party organization, which is written into the blockchain through careful digital algorithm to form the standard corresponding relationship between assets and digital currency, which is called standard digital currency

in order to realize the great leap forward development of blockchain finance, promote the new development of China's economy, accelerate the circulation of global assets, and realize the dream of rejuvenation that has been struggling for generations, Puyin group will hold the Guiyang strategic development ceremony of Puyin blockchain finance in Guizhou on December 9, 2016

the meeting will discuss the realization of digital circulation of assets by blockchain, the financial transaction mode of blockchain, and the application of blockchain services and social public instry. This conference will mark the beginning of the application of blockchain finance and the change and development of the new financial ecology

4. Let's talk about the social or economic significance of blockchain. In fact, many of the previous technologies were devoted to "proctivity". For example, artificial intelligence is a kind of progress in proctivity. The blockchain, which has greatly improved the proction relations, is committed to the proction relations. So why do you say that
because the so-called proction relationship is actually how to do business between people and business partners. And these things, originally, are in the cognitive process between people, and there is no special program to program or quantify it
for example, if you and I are good friends now, we can do business. If someone stirs up our relationship and we are not good friends, we will not do business. Even if we can make money in business, we will not do business because there is no trust between us
as for blockchain, it is actually because the data is authenticated by all nodes and backed up at the same time, so my data is as real as possible and can't be tampered with. In this case, if you believe my data, you can make a program on this basis, and then use the data to make what kind of business contract, what kind of service, what kind of service, and what kind of service, what kind of service, what kind of service, what kind of service, what kind of service, what kind of service, what kind of service, etc This "proction relationship" of commercial cooperation is programmed. In this way, we believe in the data and the program compiled by the algorithm. Because you believe in the data and the program, you can develop all kinds of apps in the program. These apps are the proction relations and what business to do. This is: blockchain is actually a reconstruction of "proction relationship".

5. Let me tell you this. Those who say no pumping are hooligans! There's no pie in the sky. Development of a mining software needs a lot of time, energy, financial and material resources, and then said free to you, and do not have any benefits, do you believe it? A lot of software with the slogan of free pumping, in fact, pumping than no one is low! For example, Changsha miners! Some tests do not require pumping, but the power of stealing calculation is higher than that of pumping! So, it is said that the mining software without pumping, give up decisively!

6. Blockchain is a term in the field of information technology. In essence, it is a shared database. The data or information stored in it is a series of data blocks associated with cryptography. Each data block contains the information of effective confirmation of multiple bitcoin network transactions. After the launch of virtual currency contract trading mode, ordinary talents can invest in bitcoin and other virtual currencies with the advantage of low threshold. Optionmr investors can trade nearly 200 kinds of mainstream virtual currency contracts such as bitcoin, lightcoin, Ethereum and bitcoin cash at a minimum of US $20, making profits through two-way trading.

7. EM is a relative measure

EM is a measure based on typesetting conversion, which defines 1em as the height of capital letters of reference font. For consistency with other metrics, CSS defines 1em as the height of the character box. The size in EM is a decimal or multiple of the reference font size. Therefore, 2em and 200% are the same, and. 75em and 75% represent the same size

you write 2em, which is 200%. Of course, you can't see the effect. If you use 0.2em, you can see the effect.

8.

Blockchain is not just a fire. It's a fire in China, but we don't know much about it. But it caused a certain sensation in the world. The historical background is that in 2008, the creator of bitcoin, Tsung Nakamoto, proposed the concept of "blockchain" in the white paper on bitcoin, and founded the bitcoin social network in 2009

several main features:

1. blockchain is essentially a decentralized database. The information in our life is centralized. For example, if you transfer money to bank a, bank a will transfer it to bank B, or more intermediaries, so as to transfer it to foreign countries or other places. Any information is transferred to a central station and redistributed. In the blockchain, all data are scattered, and the data interaction is direct, from the starting point of data to the place where it needs to be received. So data transmission is faster, more direct, and will not be manipulated

2. why is it called blockchain? Take bitcoin blockchain as an example. Every 10 minutes of bitcoin transaction information in the world will be recorded in a block, and the 10 minutes of data storage is monitored by all users. The information is transparent and cannot be tampered with. After ten minutes, the next block is generated, and the new block is linked with the previous block. If someone wants to tamper with the information of a block, he must tamper with the information of all blocks before that, which is impossible with the current technology

   What is the use of
< / OL >

1. Think about using blockchain in enterprise applications to provide more flexible, secure and efficient business processes and distributed, independent markets. Blockchain allows asset owners to track and trade valuable things, such as outstanding invoices, on a transaction "chain" that is more secure, transparent, private and self-coordinating. This capability improves the speed and flexibility of cash and asset management. For example, you are afraid to buy fake things, because a manufacturer transfers proction to several middlemen, and then you buy through middlemen, not manufacturers. If all the data is distributed, point-to-point and transparent, you can buy and pay directly from the manufacturer

The automation market of other assets will be diversified. In essence, because the software itself is controlled and open architecture, and visible to all transaction participants, the transaction based on blockchain can rece the demand for third-party supervision. If the enterprise can publish the value information to multiple potential buyers, and for all buyers, the content can be trusted and visible, and the seller can't sell again, then an open and transparent competitive environment will be formed when purchasing, and the seller can get better prices

3. Rece business transaction friction. Managing spending is a challenge for most organizations. However, blockchain enables enterprises to create self-management networks for suppliers and partners, realize contract automation, real-time payment, tracking of goods transportation, and visibility of the whole supply chain. For example, if a company uses refrigerated containers to transport perishable goods, when the container temperature exceeds a certain threshold, the IOT sensor on the truck may call the smart contract on the blockchain. This will cause the corresponding order to be cancelled, and it will also be able to automatically create a new order, so that a second batch of goods can be sent immediately. Trucks with faulty refrigeration equipment can also go to the repair Office for repair

This kind of network can rece transaction errors and information omission by recing or eliminating human-computer interaction. Moreover, by connecting buyers and sellers directly, transactions can become faster. Manage and secure decentralized private records. Its traditional instry practice is to rely on a third party, using firewalls and restricted access to protect their shared information database. And frequent data leakage events show that this approach is not very ideal. A fundamental advantage of blockchain is that each indivial data record or element is encrypted by the key of a blockchain member. Cybercrime may need to obtain each key of each member in order to access all the blockchain data. This is not to say that blockchain can guarantee 100% security of all data, which helps to rece the possibility of exposure of a large number of private records

5. A reasonable application is the record of employees or students. Employers, ecational institutions and even instry certification bodies can add new qualifications, grades or work places when necessary. Imagine giving employees a key to access all their employee records as part of a secure blockchain containing human resources. Indivials can safely share their university transcripts or employment history with other companies or ecational institutions without relying on unreliable and easily falsified faxes. Trace the origin of procts and raw materials. Blockchain can help ensure proct quality and safety by simplifying the tracking and positioning of procts and raw materials in use. For example, if an automobile manufacturer forms a quality centered blockchain including parts suppliers, parts assemblers, quality control suppliers and public management organizations (such as the National Highway Traffic Safety Administration). Then the recall process of defective parts will be faster. It makes sense to think that thousands of people die every year because of defective car parts

to sum up, blockchain is a kind of chained data structure that combines data blocks in chronological order in a sequential way, and it can not be tampered with and forged by cryptography. In a broad sense, blockchain technology uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, and uses cryptography to ensure the security of data transmission and access A new distributed infrastructure and computing method (reference network) for programming and operating data by using intelligent contract composed of automated script code. Hope to help you

webpage links

9. From the perspective of development, the biggest problem we are facing in the proction and life of the whole Chinese economy is credit. The slogan of integrity has been chanted for so many years, but the integrity of the whole society is getting worse and worse. Now not only private enterprises, but also some state-owned enterprises have begun to breach the contract. How to prove that "your mother is your mother", China claims to be the first country in the world in terms of GDP by PPP, but e to the lack of integrity, it has added huge proction and living costs. As a new technology paradigm, blockchain will bring more proctivity than everyone imagined. We regard blockchain as three layers. The first layer is technology, ledger, cryptography and authentication mechanism. The second layer is the business model, which is based on the business ecosystem reconstructed by blockchain. The third is philosophy, philosophy. The revolution of any kind of proctivity will inevitably be abstracted and sublimated into a metaphysical proction relationship, and so will blockchain. Blockchain technology and its application have the following characteristics: distributed, flat, mandatory trust, collective maintenance, reliable database, open source, privacy protection and so on. Together, these technologies will have a certain impact on many concepts and business models that we are used to. The underlying framework of laikelib blockchain is similar to Ethereum, with the idea of decentralization as the core, and is committed to building an open credit value circulation network to make credit value widely distributed.