区块链秒懂100问,区块链100问

随着区块链技术的不断发展，越来越多的人开始关注这一新兴技术，而有关区块链的问题也变得越来越多。下面我们就来回答一些有关区块链的常见问题，帮助大家了解更多关于区块链的知识。

Q1：什么是区块链？A1：区块链是一种分布式账本技术，它使用密码学和分布式记账技术来确保数据的安全性和可靠性。它是一种分布式数据库，允许多个用户在网络中共享信息，并确保这些信息的安全性和可靠性。

Q2：区块链有什么用？A2：区块链技术的应用非常广泛，涵盖金融、政府、保险、医疗、智能合约、物联网等领域。它可以用于跨境支付、资产管理、智能合约、供应链管理、数字货币等。

Q3：区块链技术的优势是什么？A3：区块链技术的优势在于可靠性、安全性、去中心化、透明度、节约成本等。它可以提高数据的安全性，降低交易成本，提高交易效率，并且可以更好地保护用户的隐私。

Q4：区块链技术有哪些缺点？A4：尽管区块链技术具有许多优势，但它也存在一些缺点，如安全性和可靠性问题、技术成熟度问题、缺乏监管问题等。因此，在使用区块链技术之前，我们需要仔细考虑这些问题。

Q5：区块链技术的发展前景如何？A5：随着区块链技术的不断发展，它的应用前景也将变得更加广阔。它可以用于支付、资产管理、智能合约、供应链管理、数字货币等，并且可以有效地提高数据安全性和可靠性。因此，区块链技术有望在未来发挥重要作用。

请查看相关英文文档

『一』 What is blockchain? Blockchain is virtual currency

Let me tell you about blockchain in a layman’s terms. There is no need to use anything advanced. Professional terminology, because that is too difficult to understand. Let me give you an analogy to make sure you understand it at a glance.

Chinese mahjong can be understood as blockchain. If the four of you ABCD are going to play mahjong, who will say hello? If A greets, then A is the initiator of this block. A is responsible for finding the mahjong parlor. Organizer A can invite BCD, or B can invite C or C can invite D. It doesn't matter.

abcd gathered in a mahjong parlor and started playing mahjong. The process of shuffling the cards in the mahjong machine, drawing cards, and playing cards by abcd can be understood as a mining stage similar to Bitcoin in the blockchain.

Everyone has different cards, which is equivalent to the algorithm in the block, but there is a goal, and they are all for the purpose of cheating. Among them, A cheated, and bcd said nothing. , everyone knows at a glance that A has won. This is called the consensus mechanism in the blockchain.

A is messed up. After A knocked down the mahjong, bcd all know how A got confused and remember it in their hearts. If A wins 10 yuan, both AbCD and A will know that A wins 10 yuan. , this is called distributed accounting in the blockchain.

Everyone who plays mahjong knows what mahjong arrangement can be used, and everyone also knows what cards can be doubled, so this can be understood as a smart contract in the blockchain.

Everyone knows the final winning card of A after A is knocked down. No one can tamper with this result because everyone is watching it. This can be understood as the immutability of the blockchain. sex.

After A announced that he was cheating, everyone did not go to another person, such as E, F, G... to verify. The same was true after B won... no regulatory agency can control it They all manage themselves. This is the decentralization in the blockchain.

By analogy, the four buddies abcd played mahjong for a day, and abcd recorded the winning and losing of each game, no matter what method they used, whether it was brain memory, video recording, or notes. Well, the more they fight, the more they can reflect the immutability, decentralization, distributed accounting, and consensus of the blockchain...

At this point, you Now you basically understand what blockchain is, isn’t it very simple?

The second question is that blockchain is not a virtual currency. Virtual currency is just a part of blockchain technology.

Many people think that virtual currency is the blockchain and Bitcoin is the blockchain. This is actually wrong. It’s just that the fame of Bitcoin has brought blockchain into the public eye.

Satoshi Nakamoto invented Bitcoin using blockchain technology, and he defined Bitcoin as a peer-to-peer electronic cash system, "electronic cash"The term indicates that what Satoshi Nakamoto wanted to invent was not just a payment system, but a currency system with an independent currency philosophy.

Today’s hotly-hyped virtual currencies, as well as mining, are resisted by many departments and countries. The fundamental purpose is not to waste resources, electricity, etc., but because people with blockchain technology Virtual currency has subverted traditional finance and can easily cause the collapse of traditional finance. I have talked about this in my previous Q&A, so I won’t go into details here.

It can be said that Satoshi Nakamoto and the Bitcoin he invented are the pioneers of the blockchain. It was Satoshi Nakamoto who brought blockchain technology into everyone’s field of vision. Blockchain technology is still widely used in finance, medical care, service industry, big data security...

Let’s talk about this big data. As we all know, the recent Didi incident due to big data security The impact is still quite large. If decentralization in blockchain technology is used, personal data can be obtained and saved through the blockchain. How can there be data leakage? In today's society, with the advancement of science and technology, as long as you use your mobile phone to connect to the Internet, you have no data security. Your personal information has already been leaked completely, so blockchain technology is inevitable for social progress. trend.

Let’s talk about blockchain. I hope you can learn something from it. You can also pay more attention to blockchain technology and improve your cognitive level. (Personally coded by hand)

Blockchain is a distributed storage solution.

Virtual currency is a supporting reward mechanism to promote this plan.

The blockchain is decentralized, so there will be no IDC computer room or centralized data center. The storage of all data is theoretically fragmented. This requires a reward to attract others to join the project, and this reward is virtual currency.

In theory, blockchain can form a dynamically stable and decentralized cloud-like computing resource provision channel.

Bitcoin is the earliest blockchain application, while Ethereum is a second-generation blockchain that can support on-chain applications. The hardware resources required for these applications are provided by miners, so they must be paid Miners pay a certain fee, and the common currency used for this fee is Ethereum.

The biggest attraction of blockchain is decentralization. In theory, applications on the chain will not disappear. No cloud containers will be lost, no data centers will be blown away by typhoons, and there will be no An organization can decide whether it stays or goes.

However, the reality is that there are still a lot of problems in on-chain applications, such as high latency, imperfect infrastructure, the reward-based miner attraction mechanism has not accelerated the on-chain speed as expected, and the virtual currency has prospered alone. Centralization returns to centralized exchanges, and other issues. There is also the inflow of black money, which is making this emerging industry full of uncertainty.

But from skillsFrom a technical perspective, blockchain technology is indeed the next generation of computer application technology.

Blockchain is a technology, a distributed and decentralized technology that can be applied to storage. Blockchain is not a virtual currency. Virtual currency is just a digital currency made using blockchain technology. Now, for example, the relationship between blockchain and digital currency is like, for example, if you build a dapp application mall on a certain chain, then you A token related to this mall can be issued.

The real connection between blockchain and virtual currency

What we are pursuing now is the application of blockchain technology. You develop a public chain and build many shopping malls, finance, defi, real estate, and tourism on this public chain. Such a dapp, this public chain has value, and then the tokens issued by this public chain have value, just like the current Ethereum, pi network

There are too many on the Internet now The so-called "blockchain digital currency", when we look at virtual currency, we look at what problems the public chain it is on can solve and what value it has, rather than blindly hype it. I think blockchain is the underlying technology. I think we only know The surface of blockchain.

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Author: Leng Leng's point of view

Block Chain is a technology, and virtual currencies like Bitcoin are products of applications on the blockchain. There are many video explanations on my homepage.

Blockchain is a technology, and virtual currency is a product produced by applying blockchain technology.

Bitcoin brought out blockchain technology, making people who don’t know why think that Bitcoin is equivalent to blockchain.

What is blockchain?

Every computer (mobile phone) is a block, which is connected through the Internet to form a blockchain.

Different from the traditional Internet, for example, when playing Douyin, each of us requests the Douyin server, and the Douyin server gives us the video. Everyone who plays Douyin cannot do without the Douyin server, and the Douyin server is our center. There is no center in the blockchain. Everyone (each block) is a server. When a block generates new content, everyone will be notified and everyone will save the new content to their own server. Each block saves The content is the same. If a new user (block) joins, it needs to synchronize the data on the blockchain and update the data to its own server first.

The advantage of blockchain is that it can ensure data security and cannot change the data. It is useless if you change one or two blocks of data. Once the blockchain data is synchronized, it will become the correct value. The traditional central server will not work. Hackers invaded the Douyin server, and all users suffered.

Disadvantages of blockchain are low efficiency. Blockchain requires synchronization of blockchain data in each block. New changes on the blockchain require synchronized updates of users on the entire blockchain network.New and inefficient.

Blockchain is a computer model of distributed data storage, point-to-point transmission, and consensus mechanism. In simple terms, blockchain is a decentralized database. How to use this technology? Is the value reflected? Under the consensus mechanism, a technology such as blockchain is formed to give a specific token, which is BTC

Blockchain is a new Internet application technology that uses distributed storage, passwords The application of emerging technologies such as science, smart contracts, and consensus algorithms can be said to be a new data transmission method that innovates existing Internet protocols. At present, blockchain technology is constantly iterating

1. Blockchain 1.0, symbolizing the birth of Bitcoin; only with Bitcoin can the development of blockchain technology officially occur

2 , Blockchain 2.0, Ethereum decentralized application platform, Ethereum introduces the application of smart contracts, which represents the beginning of a new era of blockchain technology; now everyone can create projects on Ethereum, and in recent years Many good projects have been launched

3. Blockchain 3.0, DeFi opens the era of decentralized finance. DeFi projects use smart contract technology to realize various functions of traditional financial institutions, such as derivatives, Lending, trading, financial management, asset management, and insurance, etc. There are currently mixed reviews for DEFI, which will take time to verify

Although the blockchain originated from Bitcoin, just like the first computer when the Internet first appeared, Bitcoin is mainly used by miners. Mining rewards

Blockchain is a decentralized accounting method. Virtual currency is the product of blockchain.

『二』Does blockchain change 10 cases of existing business

This article introduces the current 10 main usage scenarios of blockchain:

(1) Tracking Products in the global supply chain;

is a typical usage scenario of blockchain technology in security traceability. It can promote information tracking, query, verification and anti-counterfeiting of commodity circulation, and can significantly improve the efficiency of some links. However, the role of the blockchain can only be reflected in the chain, but it cannot cover the parts operated by people below the chain.

(2) Guarantee 3D printing quality and tracking;

(3) Create personalized and lifelong “one-stop” medical records;

Blockchain healthcare can track anyone’s complete medical history, such as medications , illnesses, injuries, and transactions across health systems, physicians, pharmacies, and health plans, and empowering patients to control their own data. Blockchain can also transfer insurance payments: smart contracts can automatically trigger insurance provisions when a clinic confirms a patient has received treatment, and prevent fraudulent or inaccurate claims. Some startups, such as the UK's Medicalchain, blockchain company Gem, MIT and other companies and universities are experimenting with this use.

(4) Simplify trade logistics;

Traditional trade involves complex import and export procedures that require all participants in the entire chain toA large number of paper documents are exchanged, resulting in high communication costs. Blockchain can optimize this system. Maersk and IBM have created a platform that integrates services such as liner, warehouse, freight forwarding, ports, customs, exporters, importers and trade finance banks into the trade ecosystem, on a data exchange platform running on the blockchain interoperate.

(5) Facilitate and secure customs trade;

Blockchain has been tested in many customs departments, including the United Kingdom, South Korea, Singapore, Costa Rica, Mexico, Peru and the 15-nation East African Group. In 2017, U.S. Customs developed 14 use cases for blockchain, which are currently being tested and evaluated. Blockchain will be particularly useful for the UK: when the UK leaves the EU customs union, its number of customs declarations will increase from 55 million to over 250 million (non-EU trade plus EU trade, which previously did not require customs documents), which is currently the case with UK software The program cannot fully handle it. Blockchain can help: It can trace the origins of products and help determine the origin and appropriate tariffs for goods, such as those destined to join the European Union’s tariff package. For the UK’s 28 border agencies, imported products such as food, safety and intellectual property compliance need to be analyzed, and blockchain projects can be shared securely and transparently in real time.

(6) Prevent voting fraud and protect voter identities;

Blockchain security and identity protection features can reduce fraud and encourage voters to believe their votes are anonymous,

increase turnout and make elections more immediate . Using the technology, voters can scan their thumbs with their smartphones and cast their ballots during their Election Day commute. If everyone votes via the blockchain, no one can vote twice. Voting records are inviolable, and the ID of each ballot is recorded instantly at every polling location.

(7) Launch crop insurance for farmers;

Crop insurance customized to specific farmer needs is often very expensive, and blockchain technology can reduce costs by determining trigger conditions and automating execution. For example, farmers can insure against extreme weather. If extreme weather affects a harvest, a blockchain-based insurance contract would immediately recognize this and pay the farmer’s claim.

Establishing a network of energy producers and users;

Decades ago, some companies introduced smart grids to provide intermediary services for energy producers and demanders. Now, blockchain can optimize smart grids and provide energy producers and consumers with a regional intermediary energy trading platform. TenneT and Brooklyn-based startup LO3 Energy are both trying this business.

(9) Create smart cities that can operate independently;

Blockchain can now amplify the impact of Douyou IoT on city operations. For example, Dubai has a pilot project to implement blockchain in city services. Dubai plans to use blockchain for more than 100 million annual government documents by 2020, including all visa applications, bill payments and license renewals.

(10) Automatically pay the exporter when the goods arrive at the foreign buyer;

Blockchain allows both parties to the transaction to access relevant informationDifferent data and real-time digital files have changed the existing information asymmetry problem in international trade. There is no need to store multiple copies of the same document across different databases for different entities. When goods arrive marked by sensors connected to the smart contract, a transfer of money from the buyer to the seller is automatically triggered.

2. Ten major problems currently faced by the blockchain industry and their analysis

2.1. Is the data on the blockchain really immutable?

Can one of the core features of blockchain, "anti-tampering", really be realized? And is "tamper-proof" really beneficial?

The report pointed out that the blockchain is not completely immutable, and gave three weaknesses of the blockchain:

(2) It may be hacked, and 51% of the chain is controlled by people who want to tamper with the results.

(3) The "garbage of garbage" problem has existed for centuries. The value of a blockchain depends on the data on the chain, and data entered into the blockchain may be inaccurate or fraudulent. One solution is to use sensors instead of manually entering data.

The so-called "51% attack" is to take advantage of computing power to cancel payment transactions that have already occurred. If someone has more than 50% of the computing power, he can find the random numbers needed to mine the block faster than others, so he actually has the absolute and effective right to decide which block. From a technical level, a 51% attack is achievable, but the cost is very high for the earliest cryptocurrencies such as BTC. They have built a huge network, which is why BTC’s network has remained stable for 10 years. reason. But with other counterfeit currencies, the risk is greater.

In addition, there is no direct benefit for the attacker to simply launch a 51% attack, and it must be linked to specific short selling and false recharge. Specifically, it is often a double spend on a certain transaction. The attacker stops attacking once. Continuous attacks are costly and will stop once successful; second, the community can issue an emergency pudding and add checkpoints to the blockchain. The community urgently agreed that the attacker’s blockchain was invalid. Therefore, there are many ways to deal with the 51% attack, and it will not be the end of the world for a blockchain.

2.2. Who owns and maintains the blockchain? And who asked about the appearance?

Responsible for problems and losses?

Since the blockchain is a decentralized user community, who will maintain it? Shouldn’t it require human adjustment and maintenance just like a website?

For permissioned chains, such as alliance chains and private chains, there is no need for incentives such as tokens to motivate people to manage, there is a manager who manages the entire network. Since there are fewer users in the network, coordination costs are relatively low. However, such networks are susceptible to security challenges, and as the number of network users increases, coordination costs will increase.

For consortium chains and private chains, since they are still very centralized organizations, the verification nodes are identified by the organization itself, so the management model is not very different from traditional centralized institutions. However, for public chains, there is no leader who coordinates the entire network system, and only relies on token incentives to coordinate different interest groups. This undoubtedly increases the inconsistency of the entire ecosystem.stability. At present, the development of the blockchain industry is in a very early stage. In addition to the relatively mature decentralized governance of BTC, in the governance of public chains such as ETH and EOS, the founder development team plays a very core role and is the "rules" of the public chain. "Maker", although the entire ecosystem has achieved partial decentralization, the founders still play a pivotal role in the direction of strategic development. Therefore, the author believes that the decentralization of blockchain can only be an ultimate goal that is constantly approaching. From the birth of the project to its maturity, its degree of decentralization should continue to increase, as shown in the figure below. In the early stages of project development, the founder and his development team play an absolute guiding role in the entire ecosystem. As the project ecosystem matures and the number of participants continues to increase, the original development team should gradually weaken its guiding role. The entire network maintenance needs to be decided jointly by all developers and users in the ecosystem. As for the final network problems, they can only be borne by all participants.

Figure: Schematic diagram of the relationship between the degree of centralization and development stages of blockchain projects

2.3. Are smart contracts really smart?

The second reason why smart contracts are not yet that smart is that their entries can be manipulated by evil actors, such as contracting parties or miners who add transaction records to the blockchain's ledger of past transactions. One study showed that 3.4% of ETH smart contracts are vulnerable to hackers.

Smart contracts can indeed optimize many intermediate programs, but judging from current industry practice, they are far from being called smart. A qualified smart contract should include all possible scenarios. Because the core essence of smart contracts is "to make the most just ruling even in the darkest environment."

The difference between Ethereum and Bitcoin is that Ethereum is Turing complete, and more types of contracts with more complex terms can be implemented through this platform. Of course, the cost of this is that the complex contract content makes it becomes more difficult to analyze. Typically, complexity is directly proportional to the probability of a vulnerability; the higher the complexity, the greater the probability of a vulnerability.

As for the concept "code is law" proposed by Ethereum, however, the code has attracted hacker attacks due to its own vulnerabilities, so it is not enough to form the authority of "law". Therefore, it needs the trust and endorsement of the government, lawyers, courts and other intermediary institutions. Compared with coordination, the current contract seems too rough.

2.4. Is there identity theft on the blockchain?

3% of social media accounts are fake, so can fake accounts be created on the blockchain? Can identities on the blockchain be stolen?

Blockchain can create a personal database for users whose data cannot be tampered with, but how to meet the user's "tampering" needs? This may be a paradox in the development of blockchain technology. Regarding user needs, we may need to start from the perspective of on-chain standards and authority management.

2.5. Can blockchains be connected to each other?

One blockchain records the data of an entity or user in one way, while another blockchain records the same data of the same entity or user in another way. a fragmentedIn a fragmented system, multiple account books are not connected to each other, which will form a world of "operational islands", or "data islands". Users need to register for multiple systems at the same time to conduct transactions with different people for different purposes.

In view of the value transfer needs of different chains, cross-chain technology is the key, which can effectively connect different alliance chains or private chains, and promote the outward expansion and connection of blockchains. The current mainstream cross-chain technologies include Notary schemes, Sidechains/relays, Hash-locking, Distributed private key control, etc.

2.6． How does the blockchain connect to off-chain databases?

If one party's data and documents are off-chain, and the other party's data and documents are on-chain, can the two parties interact? In the company's database, can half of the company's data on the blockchain interact with the other half of the data?

These challenges are well known and are being addressed. For example, the same queries and analysis can be run in on-chain and off-chain databases. The risk is that data brought from on-chain to off-chain is no longer immutable, and researchers recognize that data security and aggregating, transforming and optimizing on-chain and off-chain data sets are significant challenges.

2.7． Can blockchain facilitate money laundering?

Money laundering is a huge global problem, amounting to 1-2 trillion US dollars, accounting for approximately 2% - 5% of the total global GDP. Banks and authorities are fighting back, spending about $8 billion a year to combat corruption. Banks around the world require KYC verification.

Due to the anonymous nature of the blockchain, especially the emergence of anonymous coins, BTC has been criticized by many people as a tool for money laundering. However, the anonymity of BTC is only anonymity on the chain. The interaction between people and the chain, and the interaction between BTC and legal currency will leave traces, and it is not as "lawless" as many media have promoted. Each BTC transaction requires the transfer of a corresponding address, and the transaction records of the address can be queried. In addition, the exchange of BTC and legal currency is conducted off-chain and cannot escape supervision. If the actual identity of any party in the transaction is exposed, then all parties involved in the transaction will have difficulty escaping recourse.

2.8. Will the blockchain consume all the energy in the world?

BTC has an amazing energy demand. Operating Bitcoin for one year requires the energy consumption of Ireland for one year. Because BTC’s POW consensus mechanism requires miners to mine for transaction verification. There are concerns that as the network increases and the value of BTC rises, energy demand will grow rapidly. In fact, miners themselves have incentives to prevent this from happening, and the scalability of the blockchain is limited by availability, energy costs, and the miners' own financial resources. The current alternative is the POS consensus mechanism. The POS mechanism selects validators based on the number of currency holders.

In fact, we can see that in addition to the early batch of cryptocurrencies headed by BTCAt present, most blockchain projects have taken into account the disadvantages of POW and are constantly innovating consensus mechanisms to avoid excessive consumption of energy. Therefore, blockchain is not enough to cause such a huge consumption of energy.

2.9. Will blockchain take our jobs?

Regarding blockchain, if people can trade directly with each other, what impact will blockchain have on intermediaries such as banks and lawyers? Blockchain is unlikely to be a job killer; it will, like any technology, change the nature of work by changing companies’ business and revenue models.

When artificial intelligence becomes popular, people will continue to ask questions like this. On the one hand, we enjoy the convenience that technology brings to us, but on the other hand, we are worried that technology will replace us. The biggest challenge of blockchain is not the technology itself, but changing the traditional profit distribution model. Blockchain technology can remove certain intermediary links, break the monopoly of many resources by centralized institutions, and thus change the interest pattern. This is also the most revolutionary point of blockchain.

2.10. Is the United States lagging behind in the development of the blockchain industry?

Globally, the blockchain industry in the United States is still in its infancy. Deloitte surveyed 1,053 executives in financial services, healthcare, technology industries, telecommunications, manufacturing and other industries in 2018. According to the survey, only 14% of American respondents believe that blockchain is used in their production, compared with 49% in China, 48% in Mexico, 40% in the United Kingdom, and 36% in Canada. Plans are also lagging: 41% of U.S. companies plan to invest $1 million or more in blockchain, compared with 85% in China, 74% in Canada, 72% in the United Kingdom, and 65% in Mexico.

According to the "Blockchain China-U.S. Development White Paper" released by Silicon Valley Insight, North America is comparable to Asia in terms of the number of ICOs. In terms of financing amount, North America is far ahead with 7.85 billion. Therefore, the United States, as a major country in North America, is not lagging behind at all. On the contrary, it is still leading in many aspects.

《Harnessing Blockchain for American Business and Prosperity》

http://forex.hexun.com/2018-06-17/193222543.html

https://jiahao..com/s? id=1606478434369770769&wfr=spider&for=pc

Introduction to Tianjige: Tianjige (LD Research) was established on July 2, 2018. It is a company dedicated to exploring the unknown of science and technology, taking human development as the driving force, and taking "BASE Research for Solving Real" Problems" as the purpose of the research institute.

This article originates from Babbitt

Related questions and answers: What are the uses of blockchain technology in the business field?

The uses of blockchain technology in the business fieldWhat are its uses?

In recent years, due to the popularity of virtual digital currencies, blockchain, its underlying technology, has also begun to receive widespread attention. Blockchain has the characteristics of decentralization, trustlessness, collective maintenance, and reliable storage. It is currently widely used in the field of virtual currency.

Since the birth of Bitcoin, more than 1,600 virtual currencies have appeared in the world, and a huge industrial chain ecosystem has been formed around the generation, storage, and trading of virtual currencies. But overall, the industry is still in its infancy and is still far away from the real value use area. The core of the blockchain economy lies in the reconstruction of business logic and organizational forms, so it is necessary to obtain practical examples in multiple industries to demonstrate its value. This article will explore the business models used by blockchain in various industries from the perspective of combining blockchain with industry needs.

First of all, the core of blockchain is to solve the problem of credit:

Credit is the foundation of all commercial activities and finance. The United States has implemented trusted identification since 2011, while China has implemented a real-name system to achieve supervised information dissemination. The significance of blockchain is that it has established decentralized trust from a technical level for the first time and realized a completely distributed credit system.

Secondly, blockchain solves the problem of value exchange:

Traditional networks can achieve point-to-point transmission of information, but cannot achieve point-to-point transmission of value. Because information is allowed to be copied, and value must be authentic and unique, it is necessary to rely on a centralized organization to achieve value transfer. Blockchain perfectly solves this problem and provides a method to realize point-to-point transfer of value. During the value transfer process, accounting is realized by the network without relying on a centralized institution. Therefore, blockchain is expected to become the infrastructure for building new finance and the cornerstone of the future value Internet.

The use of blockchain

There are currently two main modes of blockchain use:

1) Native blockchain use: directly based on decentralized blockchain technology to realize value Transmission and transaction use, such as digital currency;

2) "Blockchain +" model: combine traditional scenarios with the underlying protocol of the blockchain to improve efficiency and reduce costs. It is expected that the use of blockchain in various industries will be dominated by the second model.

Blockchain has five core attributes, namely: transaction attributes (value attributes), certificate attributes, trust attributes, intelligence attributes, and traceability attributes. The above core attributes are combined with the needs of the industry to solve the industry's pain points and become the business model used by blockchain in various industries.

Blockchain + Bank

1. Cross-border payment

Cross-border payment is a pain point that has long plagued the banking industry. Traditional cross-border payment methods include two major categories: one is online payment, including electronic account payment and international credit card payment, which is suitable for retail small amounts; the other is the bank remittance model, which is suitable for large-amount transactions; both have payment cycles Long, high fees, low transaction transparency and other issues. Especially with the rise of cross-border e-commerce in recent years, convenient, fast, safe and low-cost cross-border payments have become an urgent need for the industry.beg.

The role of blockchain:

The characteristics of blockchain are deintermediation and open and transparent transactions. There is no third-party payment institution to join, which shortens the payment cycle, reduces fees, and increases transaction transparency. For example, in December 2017, China Merchants Bank teamed up with Wing Lung Bank and Wing Lung Shenzhen Branch to successfully implement cross-border RMB remittances between the three parties using blockchain technology. Its clearing process is safe, efficient and fast, greatly improving customer experience.

2. Supply chain finance

The pain points in this field are the long financing cycle and high costs. Centered on the core enterprise system of the supply chain, it is difficult for third-party credit enhancement institutions to authenticate the authenticity of various relevant vouchers in the supply chain, resulting in long manual review times and high financing costs.

The role of blockchain:

Blockchain introduces consensus mechanism, existence proof, non-tampering, traceability and other characteristics into supply chain finance, and does not require third-party credit enhancement agencies to authenticate various relevant credentials in the supply chain. authenticity, thereby reducing financing costs and shortening the financing cycle. For example, in April 2017, the listed company Yijian and IBM China Research jointly launched the blockchain supply chain financial service system "Yijian Block". The system focuses on pharmaceutical scenarios and currently has more than 30 pharmaceutical distribution companies. Successfully registered in the "Yijian Block", as of the end of July, the number of transactions had been close to 8,000, and the total investment amount exceeded 100 million yuan.

3. Digital Bills

The pain point of the digital bill industry lies in the long-term problems of "false bills" and "one vote selling many", which have brought risks to the bill financing business of the banking industry.

The role of blockchain:

The existence proof and non-tampering characteristics of blockchain effectively solve the problem of false digital bills; at the same time, blockchain solves the double-spend problem and avoids "one vote". Sell ​​more". For example, Shenzhen Blockchain Financial Services Co., Ltd. issues bill chain products to provide bill financing services based on blockchain to solve the bill financing needs of small, medium and micro enterprises. Cooperative banks include Ganzhou Bank, Guiyang Bank, Suzhou Bank, Shizuishan Bank, Langfang Bank, Wuhai Bank, Jilin Jiutai Rural Commercial Bank, Yaodu Rural Commercial Bank, Shenzhen Rural Industry Bank, Weifang Bank, Zhongyuan Bank, etc. In addition, Zheshang Bank, JD Finance, Hang Seng Electronics, HNA, etc. are also verifying blockchain digital bill services.

Blockchain + Securities

1. Asset Securitization

Asset securitization uses future income as a guarantee to obtain current financing. The pain points in this field are: there are many participating entities, many operating links, low transaction transparency, information asymmetry, and the authenticity of the underlying assets cannot be guaranteed.

The role of blockchain:

Blockchain introduces attributes such as existence proof, non-tamperability, and consensus mechanism for asset securitization. It can monitor the true situation of assets in real time and solve the problem of the underlying issues of institutions in the transaction chain. Asset trust issues. Various assets such as equity, bonds, bills, income certificates, warehouse receipts, etc. can be integrated into the blockchain and become digital assets on the chain, improving asset circulation efficiency and reducing costs. For example, in May 2017, Internet Finance, Baiqian Leasing, Huaneng Trust, etc.Partners including the Bank jointly issued an asset securitization ABS project supported by blockchain technology, with an issuance scale of 424 million yuan.

Blockchain + Insurance

1. Insurance Business

The insurance industry has problems such as information asymmetry and lack of trust between customers and insurance institutions: it is difficult for users to choose insurance products that suit them, while insurance institutions Face the risk of insurance fraud.

The role of blockchain:

The decentralized, open, transparent, and traceable characteristics of blockchain establish a good communication channel between insurance institutions and users; insurance subject information is managed uniformly on the blockchain , cannot be tampered with, helping insurance institutions avoid the risk of insurance fraud; at the same time, smart contracts can improve work efficiency and reduce costs. For example, French insurance giant AXA is using the Ethereum public blockchain to provide automated flight delay compensation for air travelers. If the flight is delayed for more than 2 hours, the "smart contract" insurance product will automatically pay claims to passengers.

2. Credit information management

The pain point in this field is that credit information agencies have limited data collection channels and a lack of data sharing, which makes it difficult to accurately characterize the credit status of individuals or institutions; in addition, there are also problems in how to guarantee the data collection process. User privacy issues.

The role of blockchain:

Blockchain has the characteristics of trustlessness, consensus, and non-tampering. At the technical level, it ensures that limited and controllable credit data sharing can be achieved on the basis of effectively protecting user privacy. And verification. For example, Ping An's blockchain credit reporting business is now online. In addition, domestic startups such as Shanghai Juzhen, LinkEye, Bubi Blockchain, etc. are also exploring joint credit reporting and safe certificate storage.

As a basic technology, blockchain has great use value in many industries with distributed processing, peer-to-peer transactions, and rapid establishment of trust relationships. Its core is to solve the problem of credit and realize Point-to-point delivery of value. Therefore, it is considered to be the cornerstone of the future value Internet.

The core of the blockchain business model is to use the innovative attributes introduced by the blockchain and combine it with traditional industry uses to realize the reconstruction of business logic in order to create new usage scenarios, or improve efficiency and reduce costs.

It is expected that the use of blockchain will first start in the pan-financial field that has high requirements for credit, efficiency, and security: the financial industry pays more attention to efficiency and security, and blockchain has a high degree of matching with its pain points, and can be used for Systematically solve trust issues, efficiency issues, default risks, etc. that exist in all aspects of financial services; blockchain’s attributes such as “transaction, certificate storage, and traceability” are more likely to generate value in the financial industry. At the same time, the market space in the financial industry is huge, and small progress can bring huge benefits.

Blockchain will also extend to all areas of social life: Blockchain solves problems such as the management, transaction, and transfer of digital assets, and therefore will play an important role in the wave of asset digitization, such as supply chain management, data Applications such as services, asset management, public services, and the Internet of Things are gradually being implemented in various fields, and "blockchain+" is becoming a reality.

『三』Explain the blockchain in vernacular

img src=' https://p26 . toutiaoimg.com/large/39b 70000088 e 51 B3 c 258 '/

Recently blocked in China various ICO financial scams, but it does not hinder the vigorous development of blockchain technology. After all, technology is innocent and can bring benefits to people. As for how to use it, it depends on people to operate it. If the operation is good, you can recommend development. If the operation is not good, it is like the major ICO projects. Find some knowledge for Internet celebrities to conduct so-called illegal fund-raising and financial fraud.

After talking for a long time, what is blockchain? When it comes to blockchain, the first thing that comes to mind for many people is Bitcoin. We need to solve a problem. Bitcoin is a blockchain, but blockchain is not Bitcoin. Simply put, blockchain is distributed ledger technology (DLT), not a token. It has many characteristics, such as decentralization, traceability, and difficulty in tampering.

(1) Blockchain is a distributed database

First of all, this is a decentralized distributed architecture system. Therefore, having only one central server or node is not called a blockchain. For example, if you go to Taobao to buy a mobile phone, you and the seller are strangers and have no basis for trust. If you give the money to the seller first, the seller may block you by not delivering the goods, and then your mobile phone money will be gone. If the seller ships first, do you pay? It is possible that you do not pay the seller after receiving the goods, and one party may lose money anyway. At this time, a third-party guarantee is needed to solve the trust problem. Just like Alipay now, you give money to Alipay and the seller will deliver the goods. When you receive the goods, the seller will receive the money.

The above example is a centralized system because all guarantee work is handled by Bora, a third-party payment company. Suppose one day Alipay wants to tamper with data, neither buyers nor sellers can do anything because all authority is in the hands of one company.

At this time, a distributed database is needed. This third party is no longer Alipay, but thousands of monitors. When you buy a mobile phone on Taobao, you will shout to everyone that I am going to XXX to buy a mobile phone, and I paid XXX yuan. The other person will yell like everyone else. I collected XXX’s mobile phone bill and sent it over. In this way, everyone knows about this transaction and everyone is recording this transaction, so it is useless if one or two nodes have problems or malicious behavior, because most nodes have recorded this matter.

(B) Blockchain uses encryption technology to ensure data security

There are two important points here: 1. Crypto-enabled hash function 2. Asymmetric encryption.

If you are interested in specific concepts, you can go online, but people without basic knowledge may not be able to understand it, because these two points are too professional. In fact, if you only know the use of blockchain, you don’t need to have an in-depth understanding of it. It is also a technical concept. All you need to know is that blockchain relies on these technical points to ensure data security and is not easily tampered with. Of course, many peopleIt is said that these two points can guarantee 100% non-tampering. I want to be a little conservative here. As an author who works in the security industry, I have always been skeptical about 100% security, so it may be more appropriate to call it difficult to be tampered with.

I will briefly introduce these two concepts and try to explain them clearly in plain English.

1. Cryptographic Hash Function

This is mainly used to verify the integrity of information. For example, I sent a message to the company leader saying that I was sick on Friday and needed to take a day off. At this time, a hash value will be generated based on the message I sent, such as: 123456. At this point, when the leader receives this message, a hash value is also generated. Because the content of the message I sent has not changed (it has not been tampered with), the hash value remains unchanged, still: 123456. This is if someone wants to tamper with this news and get sick on Friday and need to take a year off. At this time, the hash value will change, such as: 123489. That's when we learned our information had been tampered with.

2. Asymmetric encryption

It is mainly used for information encryption and authentication. It is actually two keys, one is called the public key and the other is called the private key. Public key encryption, private key decryption.

A public key is a key that everyone has. You own it, I own it. We can all encrypt with this key, but when decrypting it must be decrypted with my private key. If you don't have my private key, you can't decrypt it.

(C) The blockchain uses a consensus algorithm to reach consensus on new data.

The role of the consensus algorithm is to enable all nodes to reach a consensus on the new block. In other words, everyone must approve the new block.

For a centralized deployment system, this is simple, everything is controlled by the center, but in the distributed system of the blockchain, it is very complicated. For example, there are three nodes. A said he bought a mobile phone from XXX store and paid for it, B said he didn’t pay, and C said he didn’t pay enough. Then who do you listen to? What's more, blockchain technology is not as simple as three nodes, but a huge distributed system.

This is when a solution is needed. There is a corresponding problem in computer science called the "Byzantine Universal Problem" or "Byzantine Fault Tolerance" (BFT). This question was raised not because of Bitcoin, but because of a special background.

Early aircraft had three independent control systems. Why do we need three independent control systems? For example, in an emergency, there is a plane opposite. How to judge whether you should hide? If there is only one system, there is no choice, which is equivalent to centralized deployment. If the system breaks, you're dead. What if one of the two systems breaks? The good ones are said to hide, and the bad ones are said not to hide. The computer cannot judge the final result. Therefore, three independent systems are needed to support it, and the probability of two total failures is still very small. But this only takes into account injuries. What should I do if there is a malicious system? Is three enough? The answer is no, we need four systems to maintain consensus.

The use of blockchain is similar, because it is supported by a huge number of nodes, and each node is an independent system without interfering with each other. We can assume that the number of failed nodes and malicious nodes is limited,Therefore, it will not cause abnormal consistency of data.

Related questions and answers: What is blockchain? What is the use?

Blockchain is a new computing paradigm and distributed infrastructure that uses fast chain data structures, distributed node consensus algorithms, cryptography and smart contracts based on automated script code to produce, verify, store and transmit data. It can also be said that blockchain is a distributed ledger technology that can provide a decentralized trust mechanism in a non-trust environment, allowing multi-party participants to conduct secure and trust-based transactions without intermediaries.

The core advantage of blockchain technology is decentralization. It can realize decentralized credit-based transactions in a distributed system where nodes do not need to trust each other by using data encryption, timestamps, distributed consensus and economic incentives. Point-to-point transactions, coordination and collaboration provide solutions to the common problems of high cost, low efficiency and insecure data storage in centralized institutions.

The fields of use of blockchain include digital currency, certificates, finance, anti-counterfeiting and traceability, privacy protection, supply chain, entertainment, etc. With the popularity of blockchain and Bitcoin, many related top domain names have been registered. It has had a relatively large impact on the domain name industry.

Related Q&A: Can you explain to me what a blockchain is in an easy-to-understand way?

Er Gazi is my friend since we were young, and we were naked in Hegou together. Later, I came to the city to study and work, and lived a life as a drifter in the north; he farmed at home and did some small business, and now he has a son and a daughter, and his life is safe. He envied my so-called "seen the world", and I envied his simple life without the pressure of mortgage loans. We have completely different and mutually enviable lives??

That day, Ga Zi came to me on WeChat and asked "District" What is a blockchain?" I was stunned for a moment, how could this idiot care about such an avant-garde word? I pretended to be calm and prepared to talk about the technical principles bit by bit, but I could see the confused expression of that idiot through the screen of my mobile phone. How to explain "what is blockchain" to people who have a little bit of Internet concepts and technical foundation? This seems to be a very thorny problem??

The village commissary interprets the core of blockchain (picture quoted from the Internet)

The core essence of blockchain is "decentralization", and almost all operating modes of blockchain operate around the concept of "decentralization". Once you understand what "decentralization" is, you can basically explain the question "what is a blockchain?" For Erga, of course, he must perform a version that he can understand.

“I said, Gazi, are you still open that canteen at the east end of the village?” Gazi answered yes. I decided to use this canteen as an example to explain the actual use of blockchain in modern business and financial models. Scenario, so that he can better understand what blockchain is.

"Are there still many villagers who take credit now? By the end of the year, some of the accounts cannot be remembered clearly, and there are still many defaulters or those who refuse to accept their accounts?" At this point, Ergazi got emotional and kept complaining. Nowadays, people's hearts are not as old as before, and business is difficult to do!

"In the past, the operation mode of your canteen wasIt is a typical form of centralization. You grant credit to the villagers and all the accounting is directly connected to our villagers through you. You are the center of all accounting. " Ergazi said he understood and let me continue.

I said: "If you fail one day, then all the debts will become dead debts? It is estimated that it will be difficult to get back the IOUs written in black and white. Forget about remembering those accounts orally, but the decentralization of the blockchain can solve this problem very well. As long as the earth still exists, then the blockchain will remember that every account will exist forever." Erga became more energetic after hearing this.

The essence of the blockchain is "decentralization"

"The The essence is decentralization. Once someone takes credit from you, all the neighbors in the village will help you keep accounts. Because there are many nodes for accounting, it is neither easy to make mistakes nor others can refuse to pay, so everyone reaches a consensus. If someone maliciously fails to repay the debt, the whole village will know his character, and no one will be willing to have financial dealings with him in the future??"

At this point, Gazi was obviously a little excited. It seemed that he was I was really worried about the credit issue. Seeing that Gazi was interested, I also felt a small sense of accomplishment and continued: "Of course, the above is just an analogy. In fact, the blockchain does not really allow villagers to get paper. The pen helps you keep accounts, but it is done through the Internet and computer networking. "

At this time, Gazi was a little confused and asked: "Then what others bought from me, wouldn't everyone in the village know it? Then who would buy things from me? There is really no privacy at all. And you don’t have time to keep accounts here. Last year’s accounts are said to be this year’s. What if you keep procrastinating? "

"Okay, Gazi, your question is on point. "It seems that Gazi is not stupid at all, and he is very shrewd in doing business. I continued to explain: "So, the recording and transmission of this information are all done through encryption. What you see is a picture of numbers and English. String, and each account has a timestamp to record the time of occurrence, which cannot be relied on. "

Gazi had another question: "Is it possible that the people who owe the debt have a good relationship with the villagers, and they join forces to tamper with the accounting? Then you won’t be able to explain clearly at that time??”

“Gazi, that’s all you have, haha. "I understood Gazi's concerns and continued to explain: "The mechanism of the blockchain requires more than 51% of people to agree to tamper with a bill. Everyone has a degree of closeness and distance between them, and it is impossible for everyone to favor the same person. If it were a computer, more than half of the computers on the entire network would need to recalculate. This project would be so huge that it would be almost impossible to complete??"

In this way, through the actual situation of the canteen and combined with some scenes in life, Gazi understood What is in the blockchain: decentralization, distributed accounting, consensus mechanism, encryption mechanism, timestamps, and the characteristics of being difficult to tamper with.

Ergazi was silent for a moment, seeming to be digesting the example I just gave him. I don’t know how much he can understand the example. Not long after, he sent me a voice message on WeChat: “What does blockchain mean? In the past, when I bought goods online and paid for them, I had to go throughMa Yun's family. If there is a blockchain, can we directly trade with the seller? Anyway, the accounting is very safe. "

"Okay, Gazi, it's really clear at first glance. Blockchain is essentially a decentralized distributed ledger data cloud. Of course, it can be understood according to your understanding. "I'm very happy that Gazi can roughly appreciate the true charm of the blockchain. Fortunately, my words have not been in vain.

What is Bitcoin? (Picture quoted from the Internet)

"Then Bitcoin What is this thing again? What does it have to do with blockchain? "Gazi asked.

I thought about it briefly and decided to continue to explain to Gazi with the story of the canteen: "Your canteen, the villagers can't keep accounts for you for free all day long, right? Do you have to carry some during the holidays? This is the reward mechanism of the blockchain, and everyone who participates in bookkeeping may receive rewards. "

"Then what are the rewards based on? There has to be a rule, right? "Gazi asked very puzzled.

I explained: "Zhang San went to your store to borrow a pack of cigarettes on credit, but Li Si knew about it first and kept an account for you first, and then others knew about it. Keep accounts, then Li Si can get a small red flower as a reward ~ This small red flower is generated by the blockchain system and has no value in itself, so you do not need to pay any cost for this small red flower??"< p>“Can Bitcoin be spent as money? How is it different from the banknotes we usually spend? "Gazi continued to ask.

"Bitcoin is a digital encrypted virtual currency. In principle, it has no value itself like our banknotes. However, banknotes have a credit guarantee from the state, so they have value. Bitcoin is the value formed by consensus among Bitcoin network users, and it has tradable properties, so it can be used to carry value. "What is said here is a bit profound. I don't know if I can understand it.

I continued to explain: "Banknotes can be printed infinitely. If more are printed, inflation will occur. When we were young, popsicles worth 1 cent were very good. , now you can’t eat with 1 yuan. Of course, there are many factors that affect inflation. The number of Bitcoins is fixed, and there is no possibility of unlimited over-issuance. However, different people have different judgments on their value, and coupled with the influence of supply and demand and investor sentiment, their prices are always fluctuating. ”

What is the difference between Bitcoin price fluctuations and stocks?

“So is speculating in Bitcoin just like speculating in stocks? Can you understand it this way? "Gazi seems to know a lot.

"In fact, there are some similarities, but there are also big differences. "I continued Gazi's topic: "The price of stocks always fluctuates around the valuation of companies, and there is government supervision in the stock market. Bitcoin itself has no value. It is priced entirely based on supply and demand and player valuations. It grows wildly without any government supervision. Therefore, it may have higher risks and higher returns than stocks. "

In the end, Gazi revealed the real purpose of today. He asked me: "Can I invest in blockchain projects? ”

Gazi is a typical example of someone who doesn’t go to the Three Treasures Hall for anything.Despite a large circle, both blockchain and Bitcoin, in fact, the question he really cares about is "Is investment in blockchain projects reliable?" When these words came out, I was extremely shocked. Now The so-called blockchain investment projects have actually reached fourth- and sixth-tier cities and small towns!

Up to now, there are only three situations in investing in blockchain: mining, currency speculation, and so-called blockchain projects.

Mining and currency speculation are still the main lines of the blockchain (pictures quoted from the Internet)

The so-called mining is to obtain returns by purchasing mining equipment such as mining machines, mining virtual currencies, and then selling them for cash. . You can install the mining machine yourself, or you can find a mining pool to host it, but the core keys to profitability are "computing power" and "power consumption" as well as investment in equipment. With the sharp drop in the price of virtual currencies and the increase in mining difficulty, the current mining returns of many currencies are very unsatisfactory. Mining is obviously something only a very small number of investors who understand technology can do well, and my childhood friend Gazi obviously can’t do it.

As for "coin speculation", I have just introduced some differences between Bitcoin and stocks in the previous section. In principle, although they are both "buy low and sell high" operations, they are very different. Ordinary investors cannot determine the value of a virtual currency itself. The price is determined entirely by the relationship between supply and demand, which is somewhat similar to what we often call "market makers." On the other hand, the virtual currency trading market is extremely unstandardized, and fraud and hacker attacks often occur. The risk factor is much greater than investing in stocks. For the safety of my friends' funds, I am one of the ten thousand people who disagree with me and come to "speculate in coins"!

The "September Fourth Movement" stipulated that the issuance of virtual currency is illegal

In fact, in my opinion, most of the so-called investment projects in the market are essentially "illegal fund-raising" and "pyramid schemes." Some so-called blockchain investment projects attract investors into the circle through various packaging and inflammatory rhetoric, and then create the illusion of profitability by building a software and hardware ecosystem of issuing new coins + mining + currency speculation, and then finally run away. Our country's laws clearly stipulate that the issuance of virtual currencies is illegal.

Illegal pyramid schemes now wear the cloak of blockchain (picture quoted from the Internet)

And how to identify some pyramid schemes under the guise of blockchain? In fact, these pyramid schemes are also so-called Ponzi schemes, what we people often call "empty gloves." These so-called "direct sales" or "marketing" activities often have no actual products to circulate, and rely more on developing "downline" to ensure top-level profits. With the rise of the concept of blockchain, this MLM model has shown an intensification trend, and it even deceives people under the banner of state support for new technologies.

When Gazi asked, “Can blockchain projects be invested in?”, I realized the seriousness of the problem. Gazi is a typical young man from a small town, and his pursuit is his wife and children. But when faced with the attraction of "wealth", people often do inappropriate things. Mining and currency speculation are simply not suitable for him, let alone blockchain investment projects that are most likely "illegal financing" or "illegal pyramid schemes"!

I'll call immediatelyI got Gazi’s call and carefully conducted the above analysis??

『四』 What is blockchain

Let’s talk about some basic concepts first.

The network said that blockchain is a new usage model of computer technologies such as distributed data storage, point-to-point transmission, consensus mechanisms, and encryption algorithms. It is essentially a decentralized database, and as the underlying technology of Bitcoin, it is a series of data blocks generated by cryptography.

We try to translate "what is blockchain" into "human language".

The definition refers to the "decentralized database" nature of blockchain3354. This is very different from the traditional "centralized database" in storage, update and operation.

A centralized database can be thought of as having this shape:

For example, if I want to use Alipay to pay a Taobao seller, all data requests from when I make money to when he receives the money will be centrally processed by Alipay. The advantage of this data structure is that as long as Alipay is responsible for the efficient and safe operation of the system, others can unconditionally believe it without worrying; the disadvantage is that if there is a problem with Alipay, such as being hacked, the server being burned, a traitor appearing, and the company running away (Of course, the possibility of the above is extremely low), the balance details and other information in our Alipay will be confused.

Then some people think that this kind of low-probability event can use any technical means to avoid individual risks, and not only hand over the data to a centralized organization. For example, everyone can store and process data.

The database structure may look like this:

This picture is a schematic structural diagram of a "distributed database". Each point is a server, they all have equal rights to record and calculate data, and information is spread point-to-point. At first glance, it seems that it can indeed resist the risk caused by the crash of a certain node, but it is also very confusing and inefficient intuitively. Who will handle my information, and who has the final say on the outcome?

At this time, the "consensus mechanism" in the definition of blockchain comes into play. The consensus mechanism mainly "stipulates" the following things: who will process a data request (what qualifications are required); who will verify the results (to see if he has handled it well); how to prevent processors and verifiers from colluding with each other, etc.

Some people may like to be questioned when a "rule" is made. In order to form a stronger consensus, in addition to making the rules more reasonable, they must also be more attractive so that people are interested and motivated to participate in data processing. This involves the incentive mechanism of the public chain. We will start again later when we discuss the classification of blockchain and the role of digital currencies.

When we hand over a transaction to a distributed network, there is also a "psychological threshold": there are so many nodes that can process information, and I don't know any of them (unlike Alipay, if it hurts me, I can go and file a lawsuit against it). They all have my data, why should I trust them?

At this time, encryption algorithm (the last descriptive word in the definition of blockchain) comes on stage.

In the blockchain network, the data requests we send will be encrypted according to cryptographic principles into a string of characters that the recipient cannot understand at all. This kind ofBehind the encryption method is the support of the hash algorithm.

Hash algorithms can quickly convert any type of data into hash values. This change is one-way irreversible, deterministic, random, and anti-collision. Because of these characteristics, the person handling my data request could record the information for me, but they had no idea who I was or what I was doing.

So far, the working principle of the decentralized network has been introduced. But we seem to have overlooked one detail. The previous diagram is a net. Where are the pulleys and chains? Why do we call it blockchain?

To understand this matter, we need to clarify a few knowledge points first:

The previous picture is actually a "macro" database perspective, showing the basic rules and processes of the blockchain system for processing information. . And specifically at the "micro" data log level, we will find that the ledger is packaged, compressed, stored in blocks, and strung together in chronological order to form a "chain structure", like this:

Figure Each ring in can be regarded as a building block, and many links are linked together to form a blockchain. Blocks store data, unlike ordinary data storage: on a blockchain, the data in a later block contains the data in the previous block.

In order to academically explain the fields of each part of the data in the block, we tried to use a book metaphor to describe what a blockchain data structure is.

Usually, when we read a book, we read the first page, then the second and third pages. The spine is a physical existence that fixes the order of each page. Even if the book is scattered, the order of each numbered page can be determined.

Inside the blockchain, each block is labeled with a page number, the second page contains the first page's content, the third page's content contains the first and second page's content. The tenth page contains the previous Nine pages of content.

It is such a nested chain that can be traced back to the original data.

This brings up an important attribute of blockchain: traceability.

When the data in the blockchain needs to be updated, that is when new blocks are generated in sequence, the "consensus algorithm" comes into play again. This algorithm stipulates that a new block can only be formed if it is recognized by more than 51% of the nodes in the entire network. To put it bluntly, it is a matter of voting, and it can be elected if more than half of the people agree. This makes the data on the blockchain difficult to tamper with. If I were to force a change, there would be too many people to bribe and the cost would be too high to be worth it.

This is what people often call the "non-tamperable" feature of blockchain.

Another reason why blockchain gives people a sense of trust is because of "smart contracts."

Smart contracts are commitment agreements defined and automatically executed by computer programs. It is a set of transaction rules executed by code, similar to the current automatic repayment function of credit cards. If you turn on this function, you don’t have to worry about anything. The bank will automatically deduct the money you owe when it is due.

When your friend borrows money from you but doesn't remember to pay it back, or makes excuses not to pay it back, smart contracts can prevent breach of contract. Once the terms in the contract are triggered, such as when it is time to pay back the money, or there is a limit in his account, the code will be executed automatically, and the money he owes you will no matter what he wants.Otherwise it will be automatically transferred back.

Let’s briefly summarize. Blockchain technology is mainly decentralized, difficult to tamper with, and traceable, which represents more security and trustlessness. But it also brings new problems: redundancy and inefficiency, which requires many nodes to agree with the rules and actively participate.

This concludes the "drying" section. Next, let’s talk about unofficial history and the official history of blockchain.

A new technology is often used to serve a certain task.

Or goals. So where was blockchain first used, and who came up with it first?

Let's go back to 2008.

On September 21, Wall Street investment banks collapsed one after another, and the Federal Reserve announced that it would convert the only two remaining investment banks (Goldman Sachs Group and Morgan Stanley) into commercial banks; it hoped to survive the financial crisis by absorbing savings. On October 3, the Bush administration signed a $700 billion financial rescue package.

Twenty-eight days later, on November 1, 2008, a new post appeared in a cryptography mailing group: "I am developing a new electronic currency system that is completely peer-to-peer and does not require a third party. Three-party trust institution." The text of the post is a paper titled "Bitcoin: A Peer-to-Peer Electronic Cash System", signed by Satoshi Nakamoto.

The paper explains the design of this peer-to-peer electronic cash system with a more rigorous logic. It first discusses the problem that financial institutions are subject to "trust based" (based on credit), and then explains step by step how to achieve "no third-party agency" , and cleverly solved the technical problems left by the predecessors.

Two months later, Satoshi Nakamoto released the first version of the open source Bitcoin client and mined 50 Bitcoins for the first time. The block that generated the first batch of Bitcoins is called the "Genesis block". The genesis block was compiled into block 0 and was not uploaded to the chain. It took Satoshi Nakamoto 6 days to mine this block. This also sparked discussion in the bitcointalk forum. Bitcoin "believers" thought of the Bible, "God created the heavens and the earth in six days, and then rested on the seventh day."

Although concepts such as decentralized, token, and economy did not appear in the paper, Satoshi Nakamoto explained in detail the role of blocks and chains in the network. working principle. So, there is Block Chain.

This paper later became the "Bible" of the "Bit Cult", technology became the cornerstone of faith, and developer documentation became the "Code of Hammurabi".

After that, Bitcoin realized the first real-life payment by exchanging pizza, WikiLeaks, whose account was blocked by the US government, miraculously survived by relying on Bitcoin, Satoshi Nakamoto's "decentralization" and retirement, and the appearance of the real and the fake A series of legends such as and refuting rumors, integrating the expectations, imagination and speculation of future generations,Became a "Bible Story".

There are also people who are not satisfied with the world described in the "Old Testament" and start new sects, write the doctrines into white papers, and tell the story of their faith in the ten years after Bitcoin. Just like the writing of the 66 books of the Bible spanned 1,500 years, and after 2,000 years of interpretation, Christianity has divided into 33,000 branches.

CoinMarketCap shows that there are more than 4,900 types of digital currencies, and the overall digital currency market size is nearly 140 million yuan. Bitcoin still leads the entire digital currency market with a market share of 66%, and the recent price has been hovering around US$7,200 per coin.

So many currencies have different functions and are divided into different categories: digital currencies represented by Bitcoin are positioned as "digital gold" and have certain value storage and hedging characteristics; Ethereum The digital currency represented by Bitcoin has become the "operational fuel" in its network system; the stable currency represented by USDT and Libra has good payment properties due to its low volatility; the digital currency issued by the central bank represented by DCEP will definitely To a certain extent, it replaces M0, allowing commercial institutions and ordinary people to receive and pay without delay when they are out of cash and disconnected from the Internet.

It can be seen that after 10 years of development of blockchain technology, the first and largest application is digital currency.

Digital currency has also become an attractive reward for participants to maintain the public chain.

So besides digital currency, where else can blockchain technology be used?

Let us recall what the essence of blockchain is—a decentralized database, and its corresponding characteristics: traceability, publicity, anonymity, and tamper-proofing. In theory, you can try to use blockchain to transform traditional scenarios that use centralized databases to see if they are suitable.

Next, let’s talk about several industries and scenarios where blockchain has been successfully implemented:

Blockchain can prove the existence of a certain file or digital content at a specific time through hash timestamps, providing judicial authentication, Identity proof, property rights protection, anti-counterfeiting traceability, etc. provide perfect solutions

In the field of anti-counterfeiting traceability, blockchain technology can be widely used in various fields such as food and medicine, agricultural products, alcohol, and luxury goods through supply chain tracking.

Give two examples.

Blockchain can allow government data to be run, greatly streamlining service processes

The distributed technology of blockchain can allow government departments to be centralized on one chain, and all service processes are delivered to smart contracts, and the workers only need to be in one department Through identity authentication and electronic signature, smart contracts can be automatically processed and transferred, and all subsequent approvals and signatures can be completed in sequence.

Blockchain invoices are the earliest use of blockchain technology in China. The tax department launched the "Tax Chain" platform for blockchain electronic invoices. The tax department, the issuer, and the payee join the "Tax Chain" network through unique digital identities, truly realizing "instant invoicing for transactions" and "instant reimbursement after invoicing" - in seconds Level invoicing and minute-level reimbursement accounting greatly reduce tax collection and management costs, and effectively solve problems such as data tampering, over-reporting of one ticket, and tax evasion.

Poverty alleviation is based on blockchain technologyAnother one for floor use. Utilize the characteristics of openness, transparency, traceability, and non-tampering of blockchain technology to achieve transparent use, precise investment, and efficient management of poverty alleviation funds.

Give two examples as well.

The eID network identity operation agency guided by the Third Research Institute of the Ministry of Public Security is jointly developing a "digital identity chain" with Gongyilian, which will be issued to Chinese citizens based on the citizen's identity number as the root and cryptographic algorithm. Since it was put into operation, the eID digital identity system has served the full life cycle management of 100 million eIDs, effectively alleviating the problems of personal identity information being fraudulently used, abused and privacy leaked.

Odaily Planet Daily compiled 5 identity chain projects registered with the Cyberspace Administration of China

Blockchain technology naturally has financial attributes

In terms of payment and settlement, under the blockchain distributed ledger system, there are many markets Participants jointly maintain and synchronize a "general ledger" in real time. In just a few minutes, they can complete payment, clearing, and settlement tasks that currently take two or three days to complete, reducing the complexity and cost of cross-bank and cross-border transactions. At the same time, the underlying encryption technology of the blockchain ensures that participants cannot tamper with the ledger, ensuring that transaction records are transparent and safe. Regulators can easily track transactions on the chain and quickly locate high-risk capital flows.

In terms of securities issuance transactions, the traditional stock issuance process is long, costly and complicated. Blockchain technology can weaken the role of underwriting institutions and help all parties establish a fast and accurate information exchange and sharing channel. The issuer can handle the issuance on its own through smart contracts. , regulatory authorities conduct unified review and verification, and investors can also bypass intermediaries for direct operations.

In terms of digital bills and supply chain finance, blockchain technology can effectively solve the financing difficulties of small and medium-sized enterprises. It is difficult for current supply chain finance to benefit small and medium-sized enterprises in the upper reaches of the industrial chain, because they often do not have direct trade relations with core enterprises, and it is difficult for financial institutions to evaluate their credit qualifications. Based on blockchain technology, we can establish a consortium chain network covering core enterprises, upstream and downstream suppliers, financial institutions, etc. The core enterprises issue accounts receivable vouchers to their suppliers. After the bills are digitized and uploaded to the chain, they can be uploaded to the supplier Transfer between them, each level of supplier can realize the corresponding amount of financing with the digital bill certificate.

Give me an example.

The China Enterprise Cloud Chain, jointly launched by ICBC, Postal Savings Bank of China, 11 central enterprises, etc., has covered 48,000 companies since its establishment in 2017, with the amount of rights confirmed on the chain reaching 100 billion yuan, and factoring financing of 57 billion yuan. , cumulative transactions reached 300 billion yuan. After receiving the loan application, financial institutions can verify the authenticity of the contract on the chain and whether the contract has been verified multiple times (multiple loans); the smart contract automatically clears and settles, reducing costs and increasing efficiency; at the same time, the accounts payable of core enterprises can have The corresponding vouchers will be split by the first-level suppliers and handed over to the second- and third-level suppliers in the chain to help them with financing; core enterprises can also use this to understand whether the entire chain is operating normally and avoid emergencies. Redemption pressure.

Blockchain technology will greatly optimize the existing use of big data and play a huge role in data circulation and sharing

The aforementioned fields are relatively familiar to us.area. As more new technologies develop, blockchain may be able to be combined with them and play a role in unexpected cross-fields and new scenarios that are currently unforeseen.

In the future, the Internet, artificial intelligence, and the Internet of Things will generate massive amounts of data. The existing centralized data storage (computing model) will face huge challenges. Edge storage (computing) based on blockchain technology is expected to become a future solution. Furthermore, the non-tampering and traceability mechanism of blockchain ensures the authenticity and high quality of data, which becomes the basis for the use of all data such as big data, deep learning, and artificial intelligence.

Finally, blockchain can realize multi-party collaborative data calculations while protecting data privacy, and is expected to solve the problems of "data monopoly" and "data islands" and realize the value of data circulation.

In response to the current blockchain development stage, in order to meet the blockchain development and use needs of general business users, many traditional cloud service providers have begun to deploy their own BaaS ("Blockchain as a Service") solutions. The combination of blockchain and cloud computing will effectively reduce enterprise blockchain deployment costs and promote the implementation of blockchain usage scenarios. In the future, blockchain technology will also play an important role in many fields such as charity, insurance, energy, logistics, and the Internet of Things.

During this trial process from traditional technology to blockchain, we found that when certain scenarios have stronger demands for traceability, tamper-proofing, and decentralization, they also have problems with the weaknesses of blockchain (such as performance). , the requirements are not high, and this field is quite suitable for combining blockchain.

At the same time, in the process of blockchain evolution, it has also developed from a highly decentralized public chain accessible to everyone to a consortium chain with different permissions and maintained by multiple centers. Balances the advantages and disadvantages of the two systems.

Typical examples of alliance chains include: FISCO BCOS jointly developed by WeBank and the Golden Alliance Open Source Working Group, Fabric, a major contribution from IBM, and Ant Alliance Chain led by Ant Blockchain, etc.

These trustless systems represent more secure data authentication and storage mechanisms, where data is effectively authenticated and protected. Businesses or individuals can exchange or enter into contracts digitally, where these contracts are embedded in code and stored in transparent, shared databases where they cannot be deleted, tampered with, or revised.

It is boldly predicted that in the future, contracts, audits, tasks, and payments will all be digitized with unique and secure signatures. Digital signatures will be permanently identified, authenticated, legalized, and stored, and cannot be tampered with. There is no need for an intermediary to guarantee each of your transactions. You can conduct transactions without knowing the basic information of the other party. While improving information security, it effectively reduces transaction costs and improves transaction efficiency.

Generally speaking, there has been a lot of progress in the implementation of blockchain compared to two years ago.

Many improvements are at the bottom of the system, and users cannot directly see that blockchain is used, but they have actually benefited from it; some applications are still in pilot mode, and users have not yet been able to experience it. In the future, blockchain is expected to be used on a large scale and becomeAs one of the Internet infrastructure.

I hope that after reading this, you have a general understanding of what blockchain is and what blockchain can do.

Related Q&A: What is blockchain

Blockchain is actually equivalent to a disintermediated database, which is composed of a series of data blocks. Each of its data blocks contains information about a Bitcoin network transaction, which is used to verify the validity of the information and generate the next block.

In a narrow sense, blockchain is a chain data structure that combines data blocks in a sequential manner in chronological order, and is cryptographically guaranteed to be non-tamperable and non-forgeable. distributed ledger.

In a broad sense, blockchain is actually a distributed infrastructure and computing method, which is used to ensure the security of data transmission and access.

Blockchain infrastructure:

Blockchain is composed of six infrastructures: data layer, network layer, consensus layer, incentive layer, contract layer and usage layer.

『Wu』 Is blockchain safe?

Hi, everyone, I am your Q&A assistant - Zi Xiaochen. Recently, blockchain resistance has been widely concerned and discussed. But there are many people who don’t know much about its safety. So today we will talk about the security issues of blockchain.
First of all, would you like to hear an easy-to-understand metaphor? A friend of mine joked: "Blockchain is like a password lock. Without a password, no one can open it." Although this is simple and interesting, it makes a lot of sense. Since the blockchain uses distributed ledger technology, data is stored in a huge network, and the transmission between each node uses asymmetric encryption, the blockchain has extremely high security, and third-party attacks are very vulnerable. difficult.
Secondly, of course there are some security issues that need attention. For example, hacker attack methods such as "51% attack" can pose a threat to the blockchain. In addition, there are also security risks in virtual currency trading venues, such as Bitcoin exchanges, and you need to pay attention to precautions. Therefore, when choosing a blockchain platform or participating in virtual currency transactions, you need to know more and consider carefully to avoid losses.
In short, blockchain is an open technology, which has huge advantages in ensuring data security and preventing tampering. But we also need to be alert to potential security risks and choose reliable platforms and exchanges to participate in cryptocurrency investments.
I hope my answer can help you better understand the blockchain and its security issues. If you have any questions or want to share your experience, please feel free to message me privately! Finally, don’t forget to like, comment and forward, follow my articles, more content is waiting for you!

『Lu』 What is blockchain and what is digital currency

Blockchain is an important concept of Bitcoin and is essentially a decentralized database.
At the same time, as the underlying technology of Bitcoin, it is a series of data blocks generated using cryptographic methods. Each data block contains a batch of Bitcoins.The information of network transactions is used to verify the validity of its information (anti-counterfeiting) and generate the next block. Digital currency is an unregulated, digital currency that is usually issued and managed by developers and accepted and used by members of a specific virtual community. The European Banking Authority defines virtual currency as: a digital representation of value that is not issued by a central bank or authority and is not linked to a legal tender, but which, because it is accepted by the public, can be used as a means of payment or can be transferred, stored or traded electronically. .
The content of this article comes from: China Law Publishing House's "Comprehensive Knowledge of Legal Life Series"