How to verify the authenticity of data in decentralization

1. Decentralized exchange refers to the virtual currency exchange. Investors are expected to choose carefully. First of all, there is no formal virtual digital currency exchange or formal trading platform in China, so the state does not recognize virtual digital currency. If investors are involved, they may lose everything.

2.

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:

3. According to Hou Jietai: the so-called centralization refers to subtracting the mean value of a variable from its expected value. For sample data, each observation value of a variable is subtracted from the sample average value of the variable, and the transformed variable is centralized
for your question, subtract the mean from each measurement.

4. What's gongxinbao? I don't know once about decentralized data trading. Go ahead. Good luck.

5. The core advantage of blockchain technology is decentralization. It can realize point-to-point transaction, coordination and cooperation based on decentralized credit in a distributed system without mutual trust by means of data encryption, time stamp, distributed consensus and economic incentive, so as to solve the common high cost, low cost and low cost of centralized institutions Low efficiency and data storage insecurity provide solutions
blockchain technology has three obvious characteristics: openness, security and uniqueness
openness mainly refers to that the stored information in the blockchain is completely open to all participants. This is mainly determined by the point-to-point network storage mode of the blockchain. In the blockchain network, each node can store a of the blockchain, and the uniqueness of the blockchain can ensure that the is exactly the same between different nodes
security mainly refers to that the information stored in the blockchain block is saved after being processed by digital encryption technology, and only the private key holder can decrypt the information to obtain the real information. Other members can only see and verify the integrity and uniqueness of information, but cannot see the real information
uniqueness is mainly e to the fact that the information on the blockchain cannot be tampered with once it is on the chain, so it is unique. Of course, the uniqueness here also includes the uniqueness in space, that is, all nodes have only one version of information, and also includes the uniqueness in time, that is, the historical data cannot be changed. This uniqueness also means that the blockchain maintains the characteristics of a unique main chain in the process of operation, and once other chains appear, it is a bifurcation. The emergence of bifurcation will lead to the plication of blockchain in two different spatial dimensions. Of course, to solve this problem, we need to set reasonable consensus rules to avoid
the application fields of blockchain include digital currency, token, finance, anti-counterfeiting traceability, privacy protection, supply chain, entertainment, etc. with the popularity of blockchain and bitcoin, many related top domain names have been registered, which has a great impact on the domain name instry.

6. Blockchain is not broken. Blockchain itself is a kind of decentralized database, which can be accessed but not tampered with. Therefore, it is a very secure data chain

7. Q: What is blockchain technology? A: Blockchain technology can be understood as a public accounting mechanism. It is a technical solution rather than a specific proct. The basic idea is to establish a set of public account books on the Internet, in which all users in the network keep accounts and check accounts together, so as to ensure the authenticity and non tamperability of information. The reason why it is called "blockchain" is that the structure of blockchain storage data is composed of a chain of "storage blocks" on the network. Each block contains all the information exchange data in the network within a certain period of time, and the chain continues to grow over time. Q: What is the relationship between blockchain and bitcoin? A: Bitcoin used to be one of the most successful applications of blockchain technology. Specifically, the blockchain is a series of data blocks generated by the use of cryptography Association, and each data block contains the information of effective confirmation of multiple bitcoin network transactions. It can be said that bitcoin is a "killer application" of blockchain idea. Blockchain is the underlying technology of bitcoin, but its role is not limited to bitcoin. Q: What are the technical features of blockchain? A: Based on open source software and peer-to-peer network, blockchain can bring more advantages than traditional network in currency related fields such as transaction payment. These advantages include: decentralization, no need to trust the system, disintermediation, tamper proof, encryption security. Q: How does blockchain technology improve the authenticity and non tamperability of data? A: The newly added data blocks are linearly added to the end of the original block in chronological order, which constitutes the blockchain. In this process, the data is distributed in each computer. This decentralized storage method improves the authenticity and non tamperability of the data. When a transaction occurs, users all over the world can act as regulators. If we do not recognize the legitimacy of the transaction, the transaction cannot be concluded, and the data on the blockchain is maintained by us collectively. Q: Is there any potential defect in such a brain burning "blockchain"? A: Blockchain also has some defects to be solved, such as security risks, work efficiency and resource consumption. Since the supervision of blockchain depends on all nodes in the network, theoretically speaking, if you master more than 50% of the computing power of the whole network, you will be able to successfully tamper with and forge blockchain data. Secondly, e to the distributed storage, each node in the blockchain needs to keep a database, and any transaction in the network needs to be authenticated and recorded by other nodes, so the efficiency of the system is low. Finally, because the operation of the blockchain relies on the computing power contributed by the network nodes, these computing power do not proce actual social value, so it is generally considered that these computing power resources are "wasted". Application of blockchain in various fields when blockchain technology is published, many people think it is possible to realize DAC. DAC (full name) can be translated into distributed autonomous system, which refers to an organization system that runs autonomously without intervention and management through a series of open and fair rules. DAC has many forms. It may be a digital currency, a system or an entity, or even a driverless car. This kind of organization system can provide valuable services for customers in the form of currency transfer (such as bitcoin), asset transaction, domain name service, or any other business model. Therefore, through the idea of information sharing, blockchain technology is likely to bring profound changes in cost rection and security improvement to various instries. Application scenarios that existing blockchain technology can achieve: proof of existence can be used to confirm rights in the field of Internet finance, that is, blockchain can really realize "proving your mother is your mother". The smart contract guarantees the validity of the contract, such as the generation required by the electronic signature law; Reliability of methods for storing or transmitting data messages; The reliability of the method of maintaining content integrity; The reliability of the method used to identify the sender. The blockchain of the Internet of things can solve the problem of the coding standard interaction interface of the Internet of things. When an e-signature is signed by identity verification, the signature data is only under the exclusive control of the signer. Any changes to the e-signature after signing can be found, and any changes to the content and form of the data message after signing can also be found. The market forecasting community, August, is an example. Anyone can access and use August anywhere in the world, which may bring unprecedented liquidity and trading volume to the market. Asset trading NASDAQ OMX Group Inc is testing blockchain technology, which NASDAQ believes has the opportunity to transform traditional financial trading methods into bitcoin like ones. The bitcoin mode of e-commerce can be applied directly. Is it possible for e-commerce to become a "harmonious" market without supervision? Social news magmavc has invested $400000 in getgems (formerly known as gems), a start-up project for decentralized social communications applications. File storage directly impacts and even subverts the traditional cloud computing architecture. Chain, a data API blockchain API service provider, has received a $9.5 million investment led by Khosla ventures. Wall Street's financial companies are investing in blockchain and seizing the beach. Visa, NASDAQ and Citigroup also invested in chain, an old Jinshan blockchain start-up, with a financing amount of US $30 million. In the financial field, what can blockchain do? Specifically, in the financial field, in addition to providing a trading platform for bitcoin, Jiuding investment believes that blockchain technology can also greatly improve various asset trading systems other than the existing digital currency. For example, it plays an important role in the post transaction market proceres such as the liquidation and settlement of financial derivatives, foreign exchange, private equity, energy credit linked investment procts and other assets. In terms of speed, the time required for settlement audit in the U.S. securities market is 2 to 3 days. The application of blockchain technology is expected to rece the settlement audit time from hour level to minute level or even second level, thus recing the settlement risk by 99%, and recing the capital cost and system risk. In the blockchain, transaction confirmation and settlement are carried out at the same time. After the node transaction is confirmed by the system, it is automatically written into the distributed ledger, and the corresponding distributed ledgers of all other nodes are updated at the same time. The automatic operation mechanism can greatly shorten the settlement cycle. In terms of expenses, under the current settlement mechanism, in order to achieve a shorter settlement cycle, it is necessary to increase the settlement cost and initial investment expenses significantly. The emergence of blockchain technology makes it possible to rece the settlement cycle more efficiently and quickly, and rece the transaction intermediate proceres, so as to save a lot of money, which is the market space of the related blockchain instry. In terms of security, the integration of blockchain technology into smart contract technology can process complex derivatives transactions programmatically, making clearing more standardized and automated. The time linear stacking feature of the block itself can help the regulators identify and discover illegal operations. At the same time, the smart contract can change the compliance inspection into automation and minimize the possibility of violation from the beginning of liquidation. The 24-hour uninterrupted operation of blockchain technology can also make the data exchange processing of Pan state exchange more stable and reliable. In addition to securities transaction settlement, blockchain can also be used to register and issue digital asset ownership. Blockchain technology can greatly enhance program automation, while smart contract can write many complex derivatives trading terms into the registration and issuance program supported by blockchain technology. When a transaction occurs, blockchain network can quickly and correctly execute. In November 2015, LINQ, a new blockchain technology project cooperated by Nasdaq and chain, has completed the first private equity transaction using the blockchain based issuance and trading platform. The application prospect of blockchain in the field of accounting has also attracted the attention of a large number of people in the instry. Accounting, auditing and compilation cost a lot for global enterprises and the four accounting firms. Automatic accounting based on blockchain technology can greatly rece the relevant costs. The company does not need to recruit special auditors to audit the account book, and all transactions can be stored in the internal blockchain. Due to the irreversibility and time stamp function of the blockchain, the external auditors and regulators of the four major accounting firms can monitor the company's account books in real time by tracking these blockchains. At the same time, the institutions can greatly rece the dependence on the auditors to audit financial transactions and make the audit business more efficient. With the increasing maturity and application expansion of blockchain technology, blockchain start-ups in developed countries have sprung up. At present, the world's leading blockchain companies generally focus on transaction, payment, clearing, Internet of things and other pain point businesses. Some companies have achieved a certain scale, and have developed a relatively clear business model. At the same time, many companies have extended their business in the blockchain instrial chain, covering payment, transaction, risk control, etc., making full use of the multi-point coordination effect. At present, Jiuding investment is also focusing on the projects and applications of various blockchain technologies.

8. First, the goal of refined operation. For example, if your proct is just a tool, I'm afraid it can't be said that there are too many refined operations. Generally, it's enough to do a good job in routine user behavior analysis, and then cooperate with user qualitative research to guide proct design; If it is a content-based proct, or a proct with both function and content, it really needs to be considered. 2. Design statistical framework suppose that users will frequently interact and use functions on your app, and browse or generate content at the same time, so you need to design your statistical framework well while designing procts. 2、 Data collection first lists the data items you need, then evaluates which parts need to be reported by app and which parts can be counted in the background, and then adds them on the front and back platforms. Generally speaking, the collected data reported by app must be carefully checked and tested before release, because once the version is released and the data collection goes wrong, not only the previous efforts are wasted, but also a lot of dirty data will be brought. At the same time, the running efficiency of the client may be reced, and the gain is not worth the loss. 2. After data collation and data collection, all kinds of original data need to be processed into intuitive and visible data needed by proct managers. Here, we need to do some basic data logical association and display, so we won't repeat it. 3. Data analysis according to the statistical framework designed at the beginning, you can clearly see the data you need. Of course, the above is just a more basic analysis. If you get these data, you can analyze that users who use a function also like B function. The two are closely related. Can you consider more integration or interface adjustment in front-end design; For example, by analyzing the click stream, what are the paths for most users to visit or use the app, and do they hide the core functions too deeply? For another example, we can analyze different user attributes, such as male users and female users. Do they have significant differences in user behavior? wait. There is a big gap between the data analysis methods and models of different procts, which cannot be explained at once. So the above are more examples. 3、 Some principles need to be noted: 1. The data itself is objective, but the data interpreted must be subjective. The same data analyzed by different people is likely to draw completely opposite conclusions, so we must not analyze it with opinions in advance (for example, if we have hypotheses, we can use the data to demonstrate them); 2. Data collection by app must be of low priority. It can't affect proct performance and user experience because of data collection, and it can't collect user's privacy data (although many domestic apps don't do this); 3. Data is not omnipotent. You should trust your own judgment.

9. US $1 = RMB 6.516
1 RMB ≈ US $0.1535
US $40599 = RMB 264543.084
the data is for reference only, and the transaction price at the bank counter shall prevail. Update time: 2021-03-24 08:47

10. Chongqing jinwowo analyzes and solves problems in the following ways:
first of all, by using all data chains in the blockchain for prediction and analysis, the regulatory authorities can timely discover and prevent possible systemic risks. The decentralized characteristics of the blockchain can eliminate the information island in big data risk control, and improve risk control through information sharing

secondly, the distributed database of blockchain can improve the poor quality of big data risk control data, and solve the problems of data format diversification, data form fragmentation, lack of effective data and incomplete data content

finally, blockchain can prevent data leakage. Because the blockchain database is a decentralized database, any node's operation on data will be found by other nodes, thus strengthening the monitoring of data leakage.