Everyone is talking about blockchain, can everyone really understand?
Posted May 27, 2020 • 20 min read
The current blockchain technology is in full swing, and various industries are actively applying it, and almost everyone is talking about it. So, what exactly is blockchain technology? What is the value? How should it be applied? This article will introduce the value of blockchain technology in detail from the aspects of concept, technical composition, transfer method and development trend.
1. The past and present of blockchain technology
1 . The "Previous Life" of Blockchain
Blockchain technology is not a new technology, it is constantly evolving on the shoulders of giants. The important composition technology of the blockchain originated from the elliptic curve encryption algorithm invented in 1985. In 1995, cryptographers proposed the concept of "smart contract". Gradually, in 2005, the workload proof mechanism was invented until Satoshi Nakamoto published "Bit "Coin:A Peer-to-Peer Electronic Cash System" only marked the birth of the blockchain, so the blockchain is only 11 years old.
2 . Blockchain key technology system and technology classification
(1) Blockchain key technology system
Blockchain is a combined technology, composed of the following key parts.
- Dynamic networking, that is, point-to-point transmission network;
- Block chain data structure, block chain structure closely connected before and after;
- Consensus mechanism to maintain accounting consistency;
- Cryptography technology is the basic technology for the safety of the blockchain;
- Smart contracts are widely used on the chain.
(2) Technical classification of blockchain
Common technical categories of blockchain are public chain, alliance chain, and private chain. Tencent's blockchain is currently dominated by the alliance chain technology.
Public chain technology:The biggest feature is that the public chain has no entry and exit mechanisms. Like Bitcoin and Ethereum, anyone can come and go freely. Most public chains have the same permissions and decentralization of participating nodes The characteristics are obvious, but the performance is low. For example, Bitcoin can only process about seven or eight transactions per second.
Alliance chain technology:Refers to several organizations that form an alliance chain to do a certain scene. It has centralized management capabilities and better performance. The development of alliance chain technology is more in line with China's national conditions.
Private chain technology:Because the chain itself requires the intent and basic technology of multi-party participation and multi-party collaboration, and the participants of the private chain are all a subject, so the value is limited, and it is generally used in some internal supervision scenarios.
3 . Definition of blockchain
To take an online example, the owner of a community in Shenyang locked his garage door with 32 locks to prevent outside vehicles from occupying their parking spaces. Some netizens ridiculed that this is a blockchain. Although it is a ridicule, it does have many similarities with the connotation of the blockchain.
First of all, each lock is closely connected to the front and back, which is similar to the close connection of each block of the blockchain. Secondly, the owner can open the lock and enter the door with his own key to park, which is analogous to the needs of the blockchain. Only the private key can control the data or assets on the chain. At the same time, the action of opening the lock is done by each car owner without relying on a door-opening master to open it, and the overall decentralized mechanism is also reflected.
Blockchain technology is defined in one sentence:Blockchain is a distributed ledger technology with anti-tampering, traceability, and sharing features.
The following describes these three characteristics:
Anti-tampering:The natural accounting method of the blockchain is different from the traditional accounting method. It is a multi-center to maintain a piece of data. It can be seen from node 1 to node 6 in the figure below, if you modify the data on one node, because the other 5 nodes have full data ledgers, then they will find out who made the modification and then expel him through some mechanism Or punish him.
Traceable:The data on the chain is recorded in a unidirectional chain with time, and each data can be traced back to the originally written "person"(digital signature) and time. Each node data is redundantly stored and has a ledger. After the data is uploaded to the chain, all participating nodes can see this data information, and can trace the writing time of the data and the written "person"(digital signature)).
Share:The traditional way of accounting or data recording is a subject or a person to record. Since the advent of paper, people began to record information. At this time, only individuals were recording their own ledgers. In the era of the Internet, a centralized database is actually an organization or an individual recording information. In the era of blockchain, multiple people jointly maintain a data account book, which is a decentralized bookkeeping method. The account book of each subject has always affected the recorded data in the account book and has been shared.
4 . The difference between bank transfer method and blockchain transfer method
What is the difference between the traditional bank transfer method and the blockchain transfer method? For example, if A transfers a sum of money to A, A sends a message requesting transfer to the bank's centralized ledger, the bank modifies the balance between A and B, and then performs a query operation with B. B can see that this is The bank's transfer method uses a centralized organization to maintain account information.
The transfer method of the blockchain is different from the bank. Taking Bitcoin as an example, a local transaction is established from A to B. After the transaction is completed, it is broadcasted through P2P dynamic networking, and each node obtains this information:someone wants to transfer an account.
Then select a person to record this account according to a set of rules. The recorder may receive some rewards(rewards are correct, wrong or punished). When accounting, pay attention to whether A has the authority to transfer the balance to B. Whether B is qualified to take this asset. After the above is passed, the transaction is packaged into the block, and then the block is broadcast. After the block is broadcast to the entire network, each node will take this block After receiving all the books(blockchains) recorded before myself, this record becomes effective.
If a person modifies the ledger, there will be no impact, because the ledger is maintained by many nodes, and the modification of a single node has no effect on the entire ledger. Therefore, the blockchain does not rely on any centralized organization, and adopting a feasible technical system can completely organize individual nodes(individuals) to realize the transfer and storage of value.
5 . Block chain anti-tampering mechanism
So how does the blockchain achieve such credibility and tamper resistance? Blockchain is not perfect through one technology, but the result of the fusion of multiple technologies.
(1) According to the principles of game theory, multi-dimensional anti-tampering
The three lines in the figure below represent the three systems of cryptography principle, computing power game and multi-party witness. If each system has a 90%reliability level, and the three systems are superimposed on the relationship of the enterprise, even if someone wants to break through the final bottom line three times, the probability of achieving this goal is only one thousandth. This is the anti-tampering technology. principle. According to game theory to prevent tampering, it is guaranteed that the price paid for tampering the blockchain is greater than the gains obtained by tampering the blockchain.
(2) According to the principle of cryptography, data storage is realized with a block chain structure
In the blockchain, what exactly is a block and how are they chained between blocks?
Blocks are divided into "block header" and "block body". The block header plays a very important role in "chaining" the blocks together. One of the key points is the hash algorithm, which blocks 1 to hash to generate a fingerprint value(hash value) and put it in In the block header of block 2, block 2 is hashed again and placed in the block header of block 3, so that each block is closely connected.
If you want to modify block 1, then after block 1 is changed, the hash value of block 1 will also change, which will cause block 2 to also change, which in turn will cause block 3 to change, which makes the modification of a Existing blocks need to modify all the superimposed blocks, which makes it more difficult to modify the data on the blockchain.
To modify a block, a new block must be generated to carry the modified transaction record. For example, the Bitcoin network averages the entire network computing power every 10 minutes to calculate a block. To calculate so many blocks, it takes a lot of money. The cost of computing power, but if you use this computing power for mining, that is, account maintenance, you will get a lot of benefits. Therefore, cryptography means that the cost of tampering is greater than the gain you get from tampering, so as to ensure that the information on the chain cannot be tampered with and consistency is guaranteed.
6 . From Information Internet to Value Internet
We call the current Internet the Internet of information, and the Internet combined with blockchain will become the Internet of value. The difference between the two is mainly reflected in:The Internet transmits bearer information, and the value Internet(blockchain) transmits bearer value.
(1) Information Internet
Information dissemination tends to zero cost:The essence of the Internet is to achieve information dissemination toward zero cost, such as inter-bank transfers, group purchases, shared bicycles, games, consulting, short video and other applications, all of which are emerging after the realization of information dissemination toward zero cost. application.
Information is easy to copy, easy to tamper, and easy to leak:Internet spread and carried information is easy to be tampered with, leaked, and copied.
For example, if an author publishes an article on the Internet, the article itself is easily copied and stolen. At the same time, the data carried by the centralized database is also modified by the administrator or hacker. Therefore, once a dispute occurs, it is difficult for us to use a common electronic data as evidence Proof in judicial scenes, because the time of the data generation, attribution, and the content of the data itself are very uncertain, and there are very low-cost tampering methods that can modify the data.
(2) Value Internet
Value dissemination tends to zero cost:The information Internet has realized information dissemination tends to zero cost. One of the great characteristics of blockchain is that it can realize value dissemination tends to zero cost.
Through the private key operation mechanism, the blockchain can determine the operator of the data on the chain by strongly binding the "identity" and the private key. At the same time, the data on the chain can determine the uniqueness and cannot be tampered with.
When the article mentioned above is released, we can determine its credible release time, publisher, and content when it is released on the chain. The blockchain can confirm the rights of this article and lay a deterministic basis for subsequent potential disputes. .
Not only that, the characteristics of the blockchain can play a greater role in the value propagation scenario. The spread of value or the spread of assets strongly depends on uniqueness and cannot be tampered with, because assets cannot be copied like data, and an asset is sent for transfer After that, there is more of you and less of you. There can be no double spending. The blockchain meets the core requirements of asset dissemination well.
Value Internet has certainty:
First, each operation of the blockchain requires a private key operation, which is closely related to the "identity". This identity can be a personal identity, that is, a natural person identity, or an enterprise identity, also known as a legal person identity.
Second, the time for writing information on the blockchain is not determined by a centralized server, but is guaranteed by a number of nodes that fully participate in the blockchain network, so tampering with the information of a server is useless.
Third, the content cannot be tampered with, and the certainty of the information is guaranteed from Who, When, What. Such certainty cannot be achieved by the information Internet.
Value Internet will be participated and dominated by government departments:
The prosperity and development of the information Internet is driven by both the B-end and C-end, because the Internet carries information, entertainment, and information. However, if the blockchain is to be applied on a large scale, we believe that the government needs to become the dominant force, because both the legitimacy of the identity on the blockchain and the legitimacy of the data on the chain are required to be recognized by government departments.
The biggest application scenario of the blockchain is the low-cost transfer of value(assets), the digitalization of large assets such as real estate, securities, and land. The departments of the "asset gateway" level are all government departments, so the prosperity of the value Internet It needs to be led by government departments.
At present, the circulation of many assets requires a high time cost and money cost. If the digitalization of the mainstream assets of the society is completed and a value communication network of our 1.4 billion people is formed, the transaction costs of our entire economic society will be greatly reduced. A substantial increase in efficiency will greatly enhance China's economic vitality and create and release powerful productivity.
From "If you want to get rich, build the road first" to "If you want to get rich, build the chain first":
Government departments take the lead from top to bottom to establish China's value dissemination network, just as government departments took the lead in building highways and high-speed railways on the motherland in the past.
To build roads first, the road is essentially to speed up the flow of talents and materials in local areas. The rapid flow of materials and talents is beneficial to the market economy, and good road infrastructure has greatly contributed to China's economy.
Later, in the information age, Premier Li Keqiang repeatedly proposed that the telecommunications industry needs to "speed up and reduce fees". Essentially, it is to speed up the flow of information to further speed up the exchange of information and speed up the matching of transactions. Digital economy.
Now that President Xi has proposed a blockchain national strategy, we hope to build a blockchain value dissemination network led by the government and establish a value transfer "highway" for our 1.4 billion people, thereby accelerating the transfer efficiency of a large number of mainstream assets and reducing the transfer rate. Cost boosts our economy.
Second, the application value of blockchain
1 . What can the blockchain do?
The bottom-most feature of the blockchain is tamper resistance. This technology has been pursued by humans for many years. In the era of telecommunications, although we have used various means such as encryption to prevent information from being tampered with, to protect the authenticity of information, and have spent a lot of costs, the results have always been unsatisfactory.
Today, the emergence of blockchain technology has enabled us to find an effective electronic data tamper-proof mechanism, which is of great value. With the certainty of the data, in many scenarios the cost of mischief is increased and the foundation of trust is increased.
As mentioned above, the essence of blockchain is to make the cost of value transmission tend to zero. This value is not only an asset, but can also be understood as value data. Realizing the low-cost circulation of mainstream assets on the chain is a very challenging and very long-term affair. It cannot be achieved overnight, and the application of the blockchain needs to be implemented step by step and step by step.
I simply divided the blockchain application into the following four stages:
(1) Internet data on-chain and trust enhancement stage
Personally think that the current blockchain implementation is in the first stage. The typical application is blockchain certificate deposit. We saw that in the 19th year, the letter registration service of the Internet Information Office blockchain business accounted for more than 15%, ranking first, BATJ, etc. Tier 1 manufacturers also have blockchain services related to certificate deposit.
There are two important foundations for the blockchain to be implemented in the certification scenario. First, there is demand. There are a lot of disputes on the Internet every day. The key evidence of these disputes is electronic evidence. Electronic evidence is very easy to tamper, which makes it difficult to handle and define disputes. The court also has a headache for this. The use of blockchain allows electronic evidence to be stored on the chain as credible evidence when it is generated. When a dispute occurs, the credible data can be sent to the judicial department as key evidence.
Secondly, this scenario is high-frequency and dominant, and it is relatively simple to use at the same time. After the low-cost API is docked, the data can be uploaded to the chain as a feature value(hash value). The rare thing is that the certification scenario has room for commercialization. Judicially recognized blockchain certificate storage platform, financial lending companies or content production companies with many online disputes can pay for electronic data services. In addition to the certificate storage scene, there are scenes such as traceability and anti-counterfeiting in the first section. On the whole, the characteristic of this stage of landing is to make reliable endorsement of value data.
(2) Data transfer stage on the chain
The first stage is to increase the trust of the data on the chain, only to store the feature value(Hash value) of the data on the chain, but only to put the feature value as a field in the blockchain transaction. The use of the ability of the chain is very elementary. It is also difficult to have new expansion.
The second stage will use more chain capabilities, such as tokens and smart contracts. The typical implementation of the second stage will be blockchain licenses, blockchain contracts and other scenarios. At present, each of us and each company has a lot of licenses. There are various problems in the management and use of these licenses, such as counterfeit licenses. Such as privacy leaks on licenses, etc.
Any license is composed of three parts:the content of the certificate, the signature, and the time. If we use the blockchain, the evidence authority will issue the license on the chain in the form of a token or smart contract, such as an ID card, business license, etc. After the authority has issued the transaction, the transaction will be transferred to an individual or legal person. The person or enterprise that obtains the license can control and use the license through their own private key, so that in a specific scenario, a subject can be authorized to view the license to verify the qualification or authorization The local information of my license is given to the third party in need. In this scenario, there will be no problem of fake certificate, the management of the certificate is more convenient, and at the same time, more flexible authorization for the third party to view the license information can also be better. To the role of privacy protection.
As an example of privacy protection, if you want to go to a hotel to check in, you first need to show your ID to the hotel reception. This is to verify whether you have permission to stay in the hotel(whether it is a fugitive, etc.), but the front desk shows you You can get your name, birthday, address, ethnicity, etc. on your ID card. It is very likely that the information will be bought on the dark web after you change hands.
If you have implemented a blockchain ID card, you only need to authorize part of the information to the hotel to check, such as your public security records, your name, after checking the hotel without problems, you can stay in the hotel normally, such a scene is very real in reality Many, such as academic certificates, student cards, work permits and so on.
(3) Asset issuance and circulation stage on the chain
This stage will gradually exert the great power of the blockchain. The current circulation of assets in the society has high monetary and time costs, such as buying a house, cross-border transfer, etc. The big problem here is Internet-based information The system is suitable for the transmission of information but not for the transmission of value. The establishment of a blockchain-based value transfer network, and the competent authority to issue credible transfers of related assets on the chain will bring about a huge change in the economic outlook of society.
For example, the real estate department issues the house as a token. The token contains the latitude, longitude, area, address, etc. of the real estate. Each token corresponds to each house. The transfer of the token is equivalent to the sale of the real estate. The competent department issues it. After that, it can be given to the holders or units of various real estates, so that real estate transactions can be as convenient as red envelopes, and the token can be split. We can split a real estate into 100 copies and sell it. Everyone can take Very little money participates in property dividends, and can also be leased after buying and selling. The rental income can also be automatically sorted according to the proportion of buying a house, allowing safe and low-cost free flow of value.
If we can build a national value network chain, we can issue all mainstream assets on the chain, real estate, land, vehicles, securities, currency, etc. can be freely and safely flowed at low cost, just like information on the Internet Free flow in general.
At this stage, we will be able to achieve many interesting scenarios. For example, we now pay once a month. In the future, we might be able to pay once an hour or even once a minute, although I do n t know what this will do. But the low-cost flow of value is very helpful to economic development.
(4) Data asset stage
Everyone says that data is the oil in the Internet era and a new production factor, but the biggest problem at present is that data cannot be circulated freely as a commodity. The data is so valuable, but it cannot be reflected in our company s balance sheet. Under the current economic system, there are no suitable systems and tools to measure the specific value of data and promote the transaction of data. Massive data accumulated by humans has formed isolated islands, which cannot be coordinated to generate greater value.
The emergence of blockchain provides the underlying platform for the free transaction and pricing of data. How to use it requires further thinking and exploration, but it is foreseeable that this scenario is one of the biggest variables in the business society in the next 20 years.
2 . What can blockchain do in the banking industry?
The application of blockchain in the banking industry can be divided into two stages:
The first stage:multi-party information sharing and multi-party maintenance. For example, risk control data and black and white list data sharing can improve the data utilization level of the entire industry.
The second stage:the flowing medium of funds or assets. Realize rapid, reliable, low-cost and safe circulation of assets.
(1) Information sharing
At present, more and more information business systems are being built, forming data islands and data chimneys. Therefore, inter-institutional reconciliation data and risk control data can be considered whether to jointly maintain a data ledger through the blockchain to reach an alliance, including the sharing of blacklists and whitelists, and can also be equally maintained through some scoring mechanism. One data ledger realizes data communication and realizes a win-win situation for multiple organizations.
(2) Value transmission
The most suitable scenario for blockchain is to spread value. In addition to the central bank making digital currency, in addition, inter-bank tickets(notes), certificates(letter of credit, etc.) and letters(various guarantees) can also be abstracted as assets and treat them as Put it on the chain to do fast, reliable and low-cost circulation.
Including supply chain finance, cross-border payment, and even gradually develop to the future, there will be many assets on the blockchain for digital management, such as the establishment of a decentralized financial lending platform, the definition of loan logic in smart contracts, the entire platform can be Each independent lender participates in the supply of funds and the borrowing of funds. The bank provides a risk control model to charge a certain fee from it. The entire platform can automatically operate based on Turing's complete code logic, saving a lot of labor costs.
3.**Introduction to Tencent Cloud Blockchain Solutions and Scenarios**
As the new infrastructure is included in the national new infrastructure strategy, Tencent Cloud is also accelerating the implementation of blockchain technology in industrial scenarios. At present, Tencent Cloud blockchain technology is used in supply chain finance, trusted depository, electronic bills, and data. Factors, identity management, supply chain management, digital assets and other 7 major fields have landed.
Blockchain is the cornerstone of trust construction in the new infrastructure and the basis for the new infrastructure to build a trusted share of the underlying data. Only with the trusted sharing of data can the value of technical applications be maximized and the blocks can be better played. The role of chain in promoting data sharing, optimizing business processes, reducing operating costs, improving collaborative efficiency, building a trusted system, etc., can better help the development of blockchain technology and industrial innovation, and actively promote the integration of blockchain and economic society Development, and these are based on the true and reliable data transmission of the blockchain.
1 . Blockchain + Justice
Initially, the information was fixed. In the Internet era, when the court judged the case, it was difficult to determine whether the submitted electronic data or electronic evidence had been tampered with, because the cost of tampering was very low, and the cost of determining tampering was high, which gave The court poses great practical challenges.
"Blockchain + Justice" is an attempt of blockchain technology in the judicial industry.
(1) Micro Court + Zhixin Chain
At present, Tencent's joint "China Mobile Micro Court"(online litigation mini-procedure) has established the "Zhixin Chain"-a blockchain forensic certificate storage platform. Its core capability is to fix the electronic data when it is generated and become electronic Evidence is connected to the judicial side for the judicial to make evidence confirmation. This will resolve many disputes, including financial disputes.
(2) Zhixin Chain original content storage scene
(3) Zhixin Chain Financial Deposit Scenario
We have designed a financial certificate deposit scenario, for example, a financial institution lends a customer a loan and signs a relevant electronic contract. At this time, the electronic contract is generated when it is on-chain, and the subsequent loan data and repayment data are all on-chain certificate.
If the customer fails to return the payment within the time limit, the financial institution can use the electronic evidence deposited on the chain to initiate an online lawsuit in the "micro court" under the condition that the evidence is clear, and the entire efficiency, process, and cleanliness of the evidence can be guaranteed.
(4) Quick solution for Zhixin Chain s financial case
At present, there are more and more personal online credits. The high-frequency and low-value characteristics of online gold personal loan cases have caused distress to many banks. On the other hand, the supply on the judicial side does not match the demand on the bank side. For example, CCB needs to process 100,000 cases a year, but the judicial side may only digest thousands of cases a year, and the degree of mismatch is very large. .
Focusing on such pain points in the industry, we have designed a new process with the court:to ensure that the evidence designed in the case is credible through the generation of core electronic evidence, that is, on-chain, and then sign the electronic contract on the chain in the form of a smart contract. Time contracts are parameterized:quantifiable data such as interest rate, principal, term, amount, etc. constitute a blockchain smart contract.
Once the user expires the smart contract, it will be automatically executed. You can also process the parameters and related electronic evidence into electronic documents and send them to the court, and the court can process them in batches. Finally, the court can type the cases, and the judge can approve the case like an OA submission slip, which is credible, safe, and fast. It has also accelerated the return of funds from banks and financial institutions. At the same time, it can also help the judges of the court to reduce the burden.
2 . Blockchain + Finance
Tencent's "blockchain + finance" implementation mainly includes supply chain finance, warehouse receipt business and bill business.
Supply chain finance is the direction we think is most suitable for landing the "blockchain + finance" scenario. The core enterprise collateralized the receivables of the first-, second-, and third-tier suppliers in the bank to obtain the corresponding amount of loans, which is in line with the characteristics of the multi-department and multi-center participation of the blockchain landing, and the realization of assets Circulation split.
If the core enterprise sends 10 million yuan to the first-tier supplier to purchase things, and the first-tier supplier spends 5 million to the second-tier supplier to purchase things, these procurement contracts can be mortgaged to the bank, and the enterprise can use lower funds The cost of getting a loan really realizes the vision of the state to promote the development of physical enterprises.
In this way, the credit endorsement of the core enterprise can be transmitted to the third, fourth, and fifth-tier suppliers, which is also a key point in the speech of General Secretary Xi's blockchain:"Blockchain technology is used to solve the problem of financing difficulties and expensive financing for SMEs."
In addition to supply chain finance, in the aspect of warehouse receipts and bills, digital asset circulation can also be implemented through blockchain technology. For example, blockchain technology is used to issue, circulate and split bills. These are some specific applications. Scenes.
From its birth in 2008 to 2013, blockchain technology has only maintained a high level of popularity in the cryptography community. From 2013 to 2019, many commercial organizations such as IBM and Microsoft have been involved in the blockchain field. This is the stage of a small trial.
Since China's promotion of blockchain to a national strategic level to break through the tough positioning, Germany also listed blockchain as a national strategy in September, and more and more government agencies began to participate in the application of blockchain technology. It is believed that the next 5 years will be an era in which blockchain technology shines, and the huge changes brought by blockchain.
The keen people have noticed that the basic "soil" is gradually changing, the process is slow but the process is irreversible, and the changed "soil" will grow countless beautiful "flowers" that have never been seen before. The future is here, let us look forward to and create together!
About the Author
Wang Leqing is the product manager of Tencent Cloud Blockchain and the person in charge of Zhixin Chain. Joined Tencent in 2017 and has participated in Tencent car networking, Tencent Cloud blockchain and other projects. Currently, he is mainly responsible for Tencent Cloud Blockchain-Zhixin Chain products, and is committed to promoting the popularization and application of Tencent Blockchain technology.
_The author of this article will be in the online broadcast room of Yunjia Community Salon on the evening of June 10, to reveal more mysteries of blockchain technology, pay attention to the public account of "Yunjia Community", and see more salon live information ~ _