Author: Financial Technology Research Center, Tsinghua University block chain Dai Yi Cheng
This article is an updated version of the article " The Seventeen Golden Thoughts of Blockchain" published by the author Dai Yucheng on Weifang.com on January 24, 2019.
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Connotative blockchain concept
From the emergence of a technical concept to the subversive innovation that the public expects to become a new computing paradigm, the blockchain has been widely discussed by practitioners in various industries, and its connotation and extension are developing rapidly. On October 24, 2019, the Political Bureau of the CPC Central Committee conducted a collective study on the status quo and trends of blockchain technology development. Xi Jinping, general secretary of the CPC Central Committee, emphasized that the integrated application of blockchain technology plays an important role in new technological innovation and industrial transformation.
The blockchain concept consists of a comprehensive solution of multiple information technologies and their combinations. Through the organic integration of various information technologies, the blockchain system has the advantages that data security is difficult to tamper with, system robustness is strong, large-scale participation in the whole network, and logical automatic enforcement are more reliable than traditional systems. As a result, blockchain systems have been tried to apply in all aspects of the real economy to increase business credibility or create new new business models based on trusted blockchain systems.
The idea and concept of blockchain is often interpreted as decentralization, distributed accounting, and transfer of trust. This is of course the advantage of the overall blockchain system solution, which has led to innovative business thinking models. Change, but the overall blockchain system solution also has obvious shortcomings, including: relatively weak processing power, difficulty in balancing performance and scalability, difficulty in data protection and data security, business transformation and high cost of landing .
The author believes that the core value of the blockchain is its several data governance ideas.
The idea of data governance contained in the concept of blockchain
This article is devoted to discussing and summarizing the ideas of data governance contained in the blockchain concept. These ideas and ideas are embedded in the concept of blockchain, but they can exist from the blockchain system, including the blockchain system technology design idea, the concept of blockchain concept to the transformation of existing business systems, and the incentive mechanism empowerment business. Marketing and more. Starting from the engineering design concept of common blockchain projects such as Bitcoin, through the analysis of its specific working mechanism, we try to discover the independent design ideas for data governance mechanisms in the blockchain system. I hope that these ideas hidden in the concept of blockchain can be used individually or in combination to empower practitioners in more fields, so that the value of blockchain can be improved faster by improving the non-blockchain system. A good presentation can make up for the problems of high cost of deployment of the current blockchain system and difficulty in widespread application.
It should be noted that since the blockchain system is a new type of system with multiple technologies integrated, the absence of any one element may cause it to be called a blockchain system. Therefore, the reader may encounter a problem similar to "If you only use this one idea design system, not a complete blockchain system" in the reading process. Indeed, most of the relevant improvements in the text are to more fully reflect some of the design ideas of the blockchain, focusing on improving the capabilities of certain aspects of the system, not limited to the optimization based on the blockchain system, but rather to emphasize good ideas as much as possible. Landing reality, really helping the real economy.
The article will summarize relevant ideas from five perspectives, including: improving system security controllability, enhancing system credibility, streamlining processes to reduce costs, scientific incentives, blockchain system optimization, and blockchain are not omnipotent.
A. Improve system security controllability
1. Data accessibility helps improve overall security – multiple copy storage mode for timely data broadcast
In the blockchain system represented by Bitcoin, both the transaction initiation information, the transaction package information, and the transaction confirmation information will be spread to the entire network at the first time, synchronized by each node, and left in as many places as possible. Traces of data manipulation. The information broadcasting mode, which seems to be inefficient and wastes resources, brings about greatly reducing the probability of information inconsistency, reducing the loss caused by information conflicts, and improving the ability of information to be recovered after being tampered with.
On the one hand, in the case of damage to single-point data, it can be restored with other nodes in time; on the other hand, when the data may be tamper-attacked or processed, errors can be verified by each service at the first time. The problem is to stop the spread of malicious data and recover the problematic data nodes.
Although this idea is a very important idea of the blockchain and it is the ultimate, it is not the original blockchain system. Many traditional financial institution business systems, data center systems, and big data technology frameworks have already designed multiple copies of backup data, and are committed to improving data security and recoverability and high-speed transmission capabilities.
2. Emphasis on process data records – raw process data contains more information than the resulting data
The design of the transaction process using the Unpriced Transaction Output (UTXO) in the Bitcoin system is very subtle. The total balance of the account is not recorded in the system, but the transfer status and ownership of each value unit (ie, bitcoin) that can be transferred is recorded. The transaction process is reflected by the transfer of ownership. Through a simple data structure design, the total amount control and source tracking of limited resources are guaranteed, which not only completes the accurate record of the transfer process, but also reflects the user's assets at various time points.
The data in the business system can be divided into two categories, one is the original process data generated by the business process, and the other is the statistical result data processed by the original process data. We can refer to the original basic data as a process record and the statistical result data as a result record. In the blockchain system, each transaction needs to record to generate a new unspent transaction output that is the original process data, recording the ownership transfer process of the unexpended asset previously owned by the user. The balance owned by each person is not directly recorded, but the calculated statistical data can be output by counting all unspent transactions related to the user, and is also the result data of the wealth possessed by the user at a certain point in time. The blockchain system tells us that the agreement of the original data is the key to ensuring the consistency of the global data. As for the statistical result data, regular preservation or statistics can improve the efficiency of data processing, but it is not used as a global synchronization for consensus. And the necessary content to reach a consensus.
The idea of recording process data combined with the concept of timely broadcast of data can solve many problems that require fairness and security, such as preventing business data from being manipulated and preventing fraudulent events. Help limit the possibility of fraud by multiple parties through real-time supervision.
3. Full communication and efficient implementation – multi-party participation in voice, the only lucky person in power record
The stable blockchain system represented by Bitcoin has a low access requirement. Complex systems that have a wide range of capabilities in all aspects of the node are easily pulled down by the worst nodes, both from a security perspective and an efficiency perspective. As a system of participation by all people, Bitcoin has pioneered the full communication and efficient implementation of all nodes in the system through a clever consensus mechanism. In the case that all nodes have the opportunity to book accounts, the mechanism of competing for the full participation of the whole people is utilized. The system randomly generates the lucky bookkeepers to make the actual writing of the system data unique and meet the unpredictable randomness. . This system with complex consensus mechanism and simple writing mechanism is a perfect interpretation of complexity and simplicity, security and efficiency.
The design concept reflects a complex system involving multiple parties. If there are high security and fault tolerance requirements, try not to let too many parties have the right to write data. If this is not possible, all nodes All need to have the ability to write, it is necessary to design a reasonable mechanism to transfer the write permission of many nodes through centralized processing, avoiding the huge scheduling synchronization cost brought by multi-point writing, and ensuring that multiple parties fully participate in the consensus. The system has higher reliability and lower probability of error.
4. Use data structure to ensure controllability – chain data structure unidirectional linear growth, controllable expansion
The data of the blockchain system can't be changed again once it is confirmed, and the data can only grow linearly in one direction. This way of data recording reflects the designer's desire for data with good controllability and manageability. Controllability lays the foundation for building a globally complex consensus. The data that needs to be agreed upon across the entire network is concentrated in the latest blocks, so that the nodes participating in the consensus can focus on the part that needs to be agreed without worrying about the consistency of other data. This is a big advantage of the blockchain system that distinguishes it from traditional systems.
However, this advantage is often overlooked, and people are more concerned with the monotonic growth of the overall size of the blockchain storage data. How can a system that only increases data and cannot reduce data be trusted and used for a long time? Compared with transaction processing ability and consensus ability, this is the problem that most blockchain systems are difficult to avoid.
The author believes that the concept of the blockchain reflects the controllable, and linear one-way growth does not mean unlimited growth. By adding some design to the design mechanism of data structure growth, the blockchain can control the expansion by continuously discarding historical information. Controlled expansion here means that the amount of data in the system increases as business data increases, but some historical data that does not affect current or future consensus can be discarded or not recorded by each participant. Historical information is verifiable and has a non-destructive modification, requiring only a small number of node records to be retained.
Currently, the blockchain represented by Bitcoin does not solve this problem. Why is Bitcoin currently experiencing the problem of excessive data volume, but still need to save the entire network data to be safe? Bitcoin chains cannot be truncated, and historical blocks are discarded because some UTXO data is recorded in the previous block. If UTXO has not been transferred, there will be no relevant information in the new block. Therefore, in the future operation of this ancient UTXO, it will be necessary to trace back to the information in the very old block. Of course, this problem is not unsolvable. Introducing the blockchain system through other mechanisms can completely make the blockchain slim down while ensuring system security.
In addition, the author believes that this data structure can also lay the foundation for the introduction of data failure mechanism in future blockchain systems. Synchronize the entire network for data that is forgotten by the system in some legal frameworks. Nodes that do not want to synchronize the information of forgetting can also be regarded as untrusted nodes by other nodes, and future data growth will not be based on these nodes, thus achieving the effect of global trusted forgetting. Of course, forgotten here refers to consistent business data destruction that achieves consensus, not the clearing of data in global traces. Because the data is reproducible, once it is copied, it is difficult to completely erase the traces.
B. Streamline processes to reduce costs
5. Reduce multi-party record verification costs – unique and consistent global synchronization data record
An efficient business model must be able to agree and agree on business data. The consistency of data records is the most basic and traditional information exchange requirement. The emergence of information systems is to improve the consistency and processing efficiency of data records.
The impact of the establishment of information systems on the efficiency of information processing is spiraling upward. In the early days, in order to record consistent data, different stakeholder entities needed to maintain their own data and repeatedly check and verify at various stages of the data lifecycle (recording, use, periodic verification, change, transfer, destruction). The overhead caused by information system docking, information transmission, and information processing is unavoidable. Therefore, a large number of centralized information systems have emerged. Information mediators collect relevant data and perform unified processing through centralization, thereby reducing data verification costs and improving business efficiency. As the business becomes more complex, the social division of labor becomes smaller, the number of service entities increases, and important business information data is held by a large number of business-related entities with different functions. Leading business entities to focus on the reliability, objectivity, independence and security of information mediation. As the number of information mediators continues to increase, information is continuously replicated, and processed separately, business systems become redundant and complex in the context of multiple mediations, which in turn leads to greater information synchronization, verification, and management costs. To a certain extent, it offsets the efficiency gain brought by a single information system.
Thus, the emergence of the blockchain system subtly gives a solution to the above problem – through a unique and consistent global synchronous data record, to break through the complex and inefficient bottleneck caused by the global multi-copy data storage mode.
At present, this idea is most widely accepted by the industry, and it is also the core idea of the industry trying to apply blockchain. Many projects in the industry have made good use of this idea to reduce the cost of multi-party record verification and simplify the data verification process, thereby reducing the overall cost of the business.
However, the idea of maintaining a data record rather than multiple records does not require the application of a complete blockchain system, nor the decentralization or de-intermediation modes. If you only want to reduce the risk of inconsistency in multi-party accounting, you can solve the problem by centralizing (participating in business entities or third-party organizations) accounting or multi-agent participation in mutual supervision and multi-party real-time synchronous verification. It also improves efficiency. In fact, the author believes that many of the business problems that many alliance chains and private chains attempt to solve can be solved by this method.
6. Reduce the information interaction process of business related parties – de-intermediation (de-modularization), and finally the business side-to-point interaction
Deintermediary thinking is different from "decentralization" or "multi-centeredness." More to the center or multi-center emphasizes the concept of equality, while de-intermediation emphasizes the concept of simplification. De-intermediation refers to the organic integration of information systems with directly related business and data interactions. It will be redundant by clarifying business boundaries, rationally designing business data permissions and controls, and increasing the timely verification of business links. Participate in the main body, operation links, permission processes, and external interactions to simplify. In the specific system design, it is reflected that the redundant system modules are removed or integrated to simplify the overall processing flow. In essence, de-intermediation does not change the logic and authority of business participants, and some centralized management agencies still exist.
For the blockchain system such as Bitcoin, the accounting, confirmation and transaction processes are completely integrated into one system, which greatly simplifies the multi-system mode of trading system, clearing system and settlement system involved in traditional transaction accounting. Among them, some relatively objective business processes can be completely replaced by built-in programs, avoiding manual or system intervention as an intermediary, increasing the processing links, ensuring the objectivity and efficiency of processing, and making the participants more transparent. The entire transaction process is monitored to facilitate multiple parties to identify problems, communicate and solve problems in a timely manner.
De-intermediation reflects system integration, modularization, multi-level integration of system design ideas, and ultimately business-to-point interaction. This is in conflict with the traditional complex system design, the function layering, modularization, as much as possible to simplify the single module or a single level of processing functions, improve the overall reliability and scalability of the system. For very complex systems, the practice of this idea is relatively difficult. It requires system designers to clearly sort out and recognize business intermediaries and system intermediaries. It requires very clever and reliable design to balance efficiency and reliability. Sex. Therefore, if the processes and links involved in the business system itself are very complex, you can consider only integrating and optimizing the parts of the business model that have little change in scalability, and the other parts remain modular and hierarchical. Separate the risks between layers to make the system stable and scalable.
7. Information transparency – streamline information dissemination processes and reduce information dissemination costs
Another key idea of the blockchain system to improve efficiency is information transparency and sharing. In the real world, the disclosure of information and data requires cost. The cost includes system construction costs, information maintenance costs, and the cost of officially confirming the release of the investment. Whoever informs the information, how to publicize it, and who is responsible for it is the problem that needs to be considered in the information disclosure process. The blockchain multi-party participation consensus feature makes the information on the blockchain complete the information disclosure process in the process of being validated, which saves the cost of information disclosure, saves the cost of information confirmation, and reduces the final record. The possibility of error. Transparency and sharing can be done in different scopes. For the blockchain, the “public chain” often shares all the data on the chain (including the encrypted data) to the nodes and users on the chain. The “chain of alliances” will be shared within the small-scale alliance, and the data is not transparent to the outside.
If the business system itself can introduce information subjects, or other information to publicize the target objects, and can be included in the business system as part of the operation of the participating systems, it can greatly improve information transparency and reduce the cost of data disclosure and data maintenance. A good application scenario for the concept of information transparency is the field of securitization of various types of property rights. Whether it is a tangible asset or an intangible asset, the public disclosure of property rights itself requires a large amount of cost. If the idea of transparency of information is used, the right to be fully protected due to the high cost of confirmation and publicity can be recognized and protected. Improve efficiency.
C. Enhance credibility
8. Can verify the data structure to enhance the system credibility – time stamp, data summary, information nesting, etc. to make the data self-checking ability
Securely verifiable data structures play a vital role in disrupting traditional systems with blockchain. The information and algorithms in the blockchain system are recorded in the block, and the block grows linearly in the structure of the linked list. The linear structure of the linked list guarantees the validity and stability of data management in complex systems. In addition, the blockchain has become a subversive system, and the security-verifiable data structure plays a crucial role. Traditional database design aims to be efficient and conform to different database paradigms, while the new blockchain model is aimed at security and credibility. By introducing timestamps, data digests, information nesting, etc., the post-generated data contains the previous data information, and has the ability to check the previous data. This interlocking partial verification ensures that all information is traceable and verifiable, and thus the data is not tamperable or, more precisely, tampering data is verifiable.
In traditional computer systems, the application of information verification technology is also very common, but most of them use a single verification technology, which is not well correlated with time, space, and business information. The Bitcoin system is a good example of integration.
If a business system requires data to be tamper-proof and verifiable, and there are not many malicious participants in the business system participants, or even only mutual trust partners, the data structure of the security-verifiable data in the blockchain system can be absorbed. Thoughts, and consider abandoning resource-consumption-based billing node campaigns and other blockchain integration functions to build business systems. By redesigning the data structure in the traditional business system, adding the summary, time stamp and check information of the previous key data to the subsequent data, and the simultaneous and synchronous sharing and distribution mechanism, and introducing the multi-party storage data, the same can be achieved. The ability of internal control and self-incrimination.
9. Cure and stabilize the core logic – preset boundary conditions to reduce system changes
Blockchain systems are thought to convey value and are also valid boundary conditions throughout the lifecycle of the system. The immutability of these boundary conditions guarantees the binding and credibility of important information in the system. For the blockchain system of endogenous Tokens such as Bitcoin, although the data structures of the token information of different systems are not the same, the parameters such as the Token generation mechanism and the total amount are strictly and unchangeable. Rules have boundaries and are not arbitrarily changed so that the public trusts the system. In the era of information-replicable information, it provides a way to establish the scarcity of digital resources and achieve the purpose of so-called value transfer. It is only a clever and important application scenario that the Token total amount is limited and the generation mechanism is only the system preset boundary condition at the beginning of the system operation. Constraining the scarcity of the number of Tokens can ensure that the Token will not grow at will, and if it is combined with the scarcity of real resources in the business system, it can play different roles in multiple fields.
Every business system in real life has its own constraints. Why does the blockchain constraint have a subversive effect? The reason is that the core logic of the blockchain system (that is, the way of processing data) needs to be fixed in advance, and there are mechanisms to ensure the invariance of its core logic. The blockchain system not only realizes the immutability of data, but more importantly it ensures that the core logic of the system cannot be changed. Such a system that cannot change and upgrade rules reflects a huge credibility.
How can a system that cannot change rules be upgraded and developed? The blockchain system does not currently solve this problem perfectly, but rather implements system updates through "forking". Bifurcation is originally a short chain of non-credible data generated in a blockchain system that is not recognized by a majority of nodes. However, once the core logic code in the system needs to be modified and the operation mechanism needs to be updated, the system can inherit the business data in the original blockchain system and migrate to the new operation through the method of mutual agreement between all business related parties. In the blockchain system. This process is also known as "forking." Therefore, in the blockchain system, "upgrade", "forking" (usually divided into soft fork and hard score according to the forward compatibility of the node client) usually means recreating a new blockchain. The system, and people voluntarily voluntarily abandon the old system and transfer the business to the new system. This is the only way to upgrade the blockchain system.
10. Extensive verification to help increase trust – clear verification methods help reach consensus
The clear verification method is the foundation of the information verification mechanism. The strong vitality of the blockchain is largely due to the explicit verification method. In the research process of the blockchain project, the author is most concerned about what information is recorded on the blockchain, and whether this information can be verified by other nodes participating in the system. Many systems try to introduce blockchains to enhance business data, but do not focus on designing a clear verification method for multiple parties participating in the blockchain system, which makes the system unable to reflect the advantages of the centralized system, and it is difficult to solve the business pain points.
Bitcoin ownership transfer information (transaction information) is recorded in the Bitcoin system. The nodes with transaction requirements form effective all-network nodes through signature, encryption, digest, etc., and all the nodes that can participate in the verification can be sent to other nodes, and the nodes of the whole network check and record them. It is finally verified by the entire network node and remains in the valid blockchain. In this process, the nodes participating in the whole network have clear verification methods. By checking the signature information of the blockchain and the validity of the unsuccessful transactions in the previous block, the transaction information generated by any node has a clear verification. way. Imagine that the nodes participating in the blockchain system have no effective way of judging and verifying information. Even if there are more nodes that do not trust each other, there are more non-affiliated parties involved, and more information copies, how to ensure data. The error was discovered and corrected in time?
The correct approach is to find the information that needs consensus, find the related parties of information verification, form a multi-participating system, design an efficient information verification mechanism that conforms to the business logic, and make the data in the system more credible. Sex.
D. Scientific incentives
11. Things are rare – total amount is limited, and multiple functions are motivated
Blockchain systems such as Bitcoin, due to the lack of actual system administrators, survive in the system of vitality. If no nodes participate in the system's operating mechanism, the entire system will not be able to run persistently. Therefore, the system encourages system participants through endogenous passes (platform coins) to reward participants' contributions to the system's operations. In a system maintained by a non-centralized institution, this mechanism is ingenious and necessary, and it guarantees that the system will survive with the endogenous mechanism of humanity's pursuit of wealth.
For multi-center systems, even traditional centralized systems, incentives are often reflected in points, coupons, and external incentives. The credibility of traditional incentives depends entirely on the owner or manager of the system. Why are the points in traditional systems not as high as Bitcoin? The author believes that there are three reasons. First, the distribution mode of traditional points is opaque, and the mechanism and use are seriously affected by managers. Second, the total amount of traditional points is opaque and not scarce. Third, the use of traditional points is not widely used. Here, we don't talk much about the value of Bitcoin. It just shows the emergence of the concept of blockchain, which makes people pay more attention to the design of incentive mechanism.
An excellent incentive mechanism can design a more attractive incentive system by fully creating scarcity and fully integrating with external resources, in compliance with laws and regulations. A good incentive system can greatly help business systems win customers, increase visibility, and increase overall system value. The increase in system value in turn will provide participants with more generous incentives. This is a virtuous circle, and once the cycle begins, the value of the project will increase rapidly.
12. Utilize humanity to make up the weaknesses of the system – introduce incentives to solve system problems
As we all know, in the operating mechanism of Bitcoin, as long as the malicious computing power does not exceed 50% of the total computing power, the blockchain is safe. It is not impossible to achieve more than half of the total computing power of malicious computing power. With the advent of professional mines, the centralization of bitcoin computing power is obvious, but why is the Bitcoin system still safe and trustworthy? The use of human profitability has played a key role. Because an individual or institution that can master more than half of the network's computing power can fully obtain the vast majority of system rewards. If he chooses to do evil, although the accounting rights of the entire chain can be mastered to a certain extent, this tampering data The malicious behavior will make this blockchain no longer credible, and the assets recorded on it will be greatly reduced. A scalability problem that has both the efficiency and security of P2P systems that has long plagued the computer science community has been solved engineeringly through the introduction of incentive mechanisms.
The system may have different weaknesses. The emergence of the blockchain tells us that the design of the incentive mechanism can be combined with the design of the incentive mechanism to solve or compensate for the weakness of the system. The incentive mechanism can work only within the system, or it can be designed together with external resources. In addition, the content of the incentive, the time of generation, the calculation method, the timing of the issuance, and the disciplinary mechanism can have many different designs to make up for different problems. Bitcoin and other blockchains that provide mining incentives only provide a simple and effective design, but do provide a new way to solve system weaknesses. Through reasonable incentive mechanism design, there will be more large-scale system landing applications that are difficult to implement in the future.
E. Optimization of blockchain systems
13. Fault tolerance and consistency afterwards – the system allows for short errors, but guarantees ultimate consistency and correctness
A system that cannot accept the existence of errors, or that causes a series of problems affecting usability because of errors, is inanimate. The same is true for the blockchain system, which itself does not require that the data entered into the system be error free. This may be different from the perception of many readers. Many people think that the blockchain cannot be tampered with because of its data, so it is necessary to ensure the authenticity of the uplink data. Data cannot be tampered with and cannot be changed. In fact, the blockchain system is precisely the ability to identify errors through most nodes, and the system as a whole can correct errors in time, so that the record that is finally recorded in the blockchain and has been confirmed multiple times has credibility. This may also be a flash data governance idea that distinguishes the blockchain system from the traditional P2P systems in the computer field.
The computer field pursues efficiency and consistency in the distributed processing process. For the repair and correction of erroneous data records, a separate mechanism is usually designed to ensure. Compared with the traditional database, the blockchain introduces a consensus mechanism to ensure that the after-error data can not be falsified, and provides more tolerance for the emergence and repair of errors. This important idea is often overlooked by many blockchain designers. Many projects are pursuing the promotion of short transactions and confirmation speeds, which will lead to weakening or even sacrificing the verification process of other nodes. At the same time, earlier and faster confirmation will also cause problems. The nodes involved in generating data need to meet more stringent requirements such as the fact that the generated data can not be erroneous, which has led to difficulties in the landing process of many blockchain projects. Because the system user will carry the burden that the data must be correctly input at one time, it is necessary to choose the uplink data very conservatively and cautiously. In the end, the application scope of the blockchain is narrow, and many data with the possibility of error are difficult to participate in the business upgrade and transformation in combination with the advantages of the blockchain.
The author believes that the design of the blockchain not only does not require the data to be correctly input, but provides a very inspiring processing mode and design idea for the above problems: when there is data error, the data associated party can perceive the data error in time. And in the first time through some sort of negotiation mechanism to use a certain mechanism in a timely manner from the inconsistent data (the minority is obeying the majority in the bitcoin) to quickly pick out the correct data, and finally make the data globally recognized. This data validation process takes into account possible errors and systemic errors in the actual business and is highly inclusive. It is worthwhile for the business system to refer to the error handling correction process design. When designing a business system (or blockchain system) that requires data validation, it is necessary to weigh the data validation time window and the system error correction capability to design a data validation mechanism (consensus mechanism) that suits its business characteristics. The blind pursuit of short-term confirmation will greatly limit the applicable business scenarios of the system, which is extremely unfavorable for the application of the new system.
14. Let users be responsible for their actions – users are only willing to proactively protect as the sole core operational credentials
The private key plays a key role in bitcoin transactions. The private key not only plays the role of identity verification, but also plays an irresistible role in user operation. When a transfer transaction is made in the Bitcoin system, the private key is used as the sole credential for the user to control his or her own assets, and the user has sufficient independence and autonomy to perform the transfer operation. Since this operation directly affects the user's interests and depends entirely on the personal will of the user holding the private key, the user has a strong incentive to keep his private key information. In this case, the private key can really play a role in the user's responsibility for his actions.
However, the design of the private key mechanism of some blockchain projects does not motivate users to self-manage private keys. If you only have the possession key as the decryption key for viewing the encrypted information on the chain, even other people who need to view the encrypted information on the chain can obtain the viewing or management of similar user keys after the user's permission (and gives the user some incentive). Permission to undermine the uniqueness of the private key owner can undermine the privacy and security of the private key and cause the private key to have a lack of autonomy. When the individual or the enterprise lacks the willingness to keep the private key, the blockchain system application party can only use other methods to replace the user's private key, the proxy user uses the private key to sign and operate, or the proxy user views the encrypted information original text. Such an application model, although designed with a public-private key encryption mechanism, is in fact essentially indistinguishable from the traditional centralized Internet multi-user service model. Although the use of blockchain can make the information on the chain difficult to tamper, and the role of the company's key data self-certification, but the user's vision of self-administered data is difficult to achieve.
If the project side explores the core operations of the user in combination with its own business characteristics, and combines the asymmetric encryption solution to ensure that the private key is not copied and abused, it can achieve the effect that the user is responsible for his own behavior. At the same time, users will be more motivated to maintain and maintain their private keys. Of course, I am very much looking forward to the innovation of technology to create other ways to help securely store private keys, reducing the cost of user memory and saving private keys.
Of course, the private key can play the role of user identity verification, but similar to the traditional username and password mechanism, it is not a very friendly authentication method. At present, many mature use of artificial intelligence, user behavior analysis, biometric verification and other methods of identity verification. For current centralized Internet companies, these methods may be more appropriate.
15. Relentless pursuit of relative fairness – a single design consensus mechanism is difficult to maintain long-term equity
The blockchain system is credible and is given the aura of “passing value”, which is inseparable from its pursuit of fairness. Systems such as Bitcoin and PoW-based consensus have gone the farthest in the pursuit of fairness without the need for a credibility organization to endorse. The emergence of dedicated chip miners and mines essentially broke the fairness pursued by the Bitcoin consensus mechanism. Bitcoin was originally designed to allow enough people and nodes to participate in accounting. The subtext is to use the mutual participation of untrustworthy subjects to restrict each other. However, although the mines and mining machines have made more people in the Bitcoin system participate in bookkeeping, they have not been able to involve more people with different interests. A large number of miners with the same interests have reduced the discourse power of other nodes with different niche interests in the system, resulting in the abduction of bitcoin by large mines. This weakening of fairness has caused some industry's aggressive behavior to significantly affect the computing power of Bitcoin at the end of 2018, which in turn affected the industry's perception of the blockchain. People feel that Bitcoin's fairness mechanism is limited and will be kidnapped by miners and interest groups. But from the perspective of fairness and credibility of information records, Bitcoin's PoW consensus mechanism has taken a huge step compared to traditional systems.
Once a static mechanism is designed, if there is no support from basic science such as mathematics to prove that it is difficult to be broken, someone will try to attack it and may be destroyed by others in the future. Therefore, in the case that a trust consensus mechanism is difficult to obtain mathematical proof of its performance, a common idea to prevent the system from being destroyed is to let the consensus machine brake. Combined with the idea of curing stable core logic mentioned in the article, a possible more fair consensus mechanism in the future needs to ensure the dynamic change of its consensus mechanism by means of code at the beginning of design, and design a reasonable endogenous fairness evaluation. The system makes the consensus mechanism in the system continuously adjust the relevant parameters and change the consensus mechanism. This may reduce the research and development power of the dedicated “mine machine” to a certain extent, further decentralize the power and ensure the fairness of the participating entities and the whole system.
F. Blockchain is not a panacea
16. The need to deal with real-world data requires a centralized medium—a predictor to help explore the relationship between the digital world and the physical world.
The concept of the prophecy machine was not born with bitcoin, but was born out of people trying to record real-world physical world information in blockchains. The prophecy machine attempts to introduce non-chain-primary data for the blockchain, opening up the real-world physical world and the digital world on the chain.
The important bottleneck encountered by many blockchain applications is what people often mention: how to solve the problem of data chaining. The author believes that this problem is not caused by the fact that the blockchain mechanism represented by Bitcoin is not yet mature, and the design mechanism is flawed, but because the posterity is using the blockchain technology in combination with its own business scenarios and industry knowledge, The expectation that chain technology gives way out of thin air.
In the design of Bitcoin, the data and the transaction book are inseparable. The data is born on the chain and used in the chain, which naturally guarantees the security of the data. The role of the blockchain is to make the original reliable data maintain the reliability and credibility of the data life cycle.
Therefore, the question worth considering is that there is no motivation and willingness to falsify what kind of data is in the process of data chaining. If the data itself has this feature, the blockchain system can easily fall to the scene. If the data does not meet such characteristics, the problem of fraud in the data-winding process still needs to rely on the regulatory agencies and credible institutions in the society to solve the problem of fraud in the data data uplink process, or combine the aforementioned data in time. The idea of transparency in broadcasting and information maximizes the cost and difficulty of fraud.
17. The entanglement of publicity and privacy – the extensive landing of blockchain requires a data privacy protection framework
Relying on the technology of cryptography, the electronic signature can guarantee the authenticity and integrity of the electronic information and the non-repudiation of the signer, and it is helpful for the quality assurance of the uplink data in the blockchain system. But for the data itself, especially the privacy data protection, most blockchain projects still only stay at the level of data encryption. The emergence of this approach is not closely related to the emergence of blockchain concepts and technologies. Simply encrypting the data and unloading the data does not improve the security of the private data. Instead, the information can only be added to the information in the blockchain. Once the information decryption key is leaked, the information will not be destroyed in time.
Although encryption and uplinking do not protect data well, some blockchain projects attempt to solve this problem to some extent by combining zero-knowledge proof and multi-party secure computing. At present, it seems that the open and transparent nature of the blockchain has promoted the exploration of encryption and data information protection technologies.
When solving data and privacy protection, if you think that encrypting the data and providing the corresponding key to ensure the security and autonomy of the data, it may be difficult to achieve. The reproducibility of the information data itself does not disappear because it is encrypted and equipped with the corresponding key. Although the Bitcoin system is anonymous in transaction, it is difficult for the transaction initiator to correspond to a specific individual in the physical world, but it does not reflect that the data on the chain has a protection mechanism.
Although it is difficult for people to make information unreproducible and cannot be taken away, there are still some other technical means for information tracking and information identification. Through zero-knowledge proof, secure multi-party calculation and other methods, the algorithm can be deployed to output the processed data after the data is not stored, so as to achieve the protection and protection of the data, but the purpose of the data attribution is not changed. A safe and controllable method that does not leak. The application scope of the blockchain will also land in a wider range of fields as these data security technologies and frameworks mature.
The emergence of blockchain does show a lot of data governance mechanisms and ideas from many angles, and the concept of excavation is not limited to the content mentioned in this article. Readers are welcome to criticize and correct these views. I believe that by fully utilizing and tapping the data governance ideas of blockchain, it can help more research projects and applications, and empower the real economy. The Blockchain Research Center of the Institute of Financial Science and Technology of Tsinghua University has long been concerned with the research on blockchain technology development, application landing, policy supervision, etc., and hopes to unite the excellent blockchain practitioners to accelerate the success of the blockchain. Promote the development of blockchain and economic and social integration.