Author | Qin Xiaofeng

Editor | Hao Fangzhou

Produced | Odaily

Author | Qin Xiaofeng

Editor | Hao Fangzhou

Produced | Odaily

In the past four months, Bitcoin has successively broken through the 20,000, 30,000, and 40,000 US dollars mark, and crypto investors have shouted "blockchain revolution".

In our country, the policy encourages "no currency blockchain". Countries and enterprises will also focus on the development of industrial blockchain.

In the exploration of the blockchain, China has gradually found its own path: the alliance chain replaces the public chain, and finally becomes the preferred choice for application landing. BAT giants such as "Ant Chain", "Baidu Super Chain" and FISCO BCOS are undoubtedly the leaders of alliance chains. At the same time, emerging alliance chain platforms such as PlatONE and BSN have also been born, constantly promoting the application practice of industrial blockchains .

Then in the past year, Odaily explored how the alliance chain has developed, what common problems it has faced, and what breakthroughs have been made in technology.

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1. The alliance chain is more suitable for the national conditions

In recent years, blockchain has become the focus of both national policy and the public.

The national "two sessions" in 2017 mentioned blockchain technology for the first time; in 2018, the government work reports of the national and local governments once again mentioned "blockchain" technology on a large scale; in 2019, the central government determined that "blockchain as a core technology An important breakthrough for independent innovation", "blockchain" has also become a hot word of the year; Policies have been introduced to support.

In addition, the development prospect of China's blockchain market is very optimistic. According to the "Global Blockchain Expenditure Guide" released by IDC in August 2020, the overall expenditure scale of China's blockchain market will reach 2.28 billion US dollars in 2024, with a compound annual growth rate of 51%.

Driven by the broad market prospect and the support of national policies, the demand for access to blockchain in all walks of life has surged, and the concept of industrial blockchain has come to the stage.

Odaily noticed that in the application of industrial blockchain, the preferred bottom layer is the alliance chain rather than the public chain.

Yao Qian, general manager of China Securities Depository and Clearing Co., Ltd. and former director of the Central Bank’s Digital Currency Research Institute, once said that the alliance chain is more suitable for China’s national conditions. "Because the frontier of technology lies in the public chain, we should uphold an objective research attitude towards the public chain. Based on the real environment, the alliance chain may be a better choice for application landing. Only by strengthening the application and innovative development of domestic cryptographic algorithms can we guarantee my country's blockchain Safe and controllable."

At its root, the alliance chain has three advantages over the public chain: one is performance, the other is controllable by the participants, and the third is privacy information protection.

At present, the highest TPS processing capacity of the public chain can only reach a few thousand, which seems powerless in the processing of traditional transactions. This is mainly because the public chain is more pursuing decentralization, so performance is sacrificed in the balance of security, performance and decentralization.

However, in the enterprise service scenario, the number of participants in the alliance chain is relatively more controllable, and it is easier to make breakthroughs in terms of high performance and security. The TPS can reach tens of thousands or even hundreds of thousands. Taking the block chain platform as an example, its transaction response time reaches the millisecond level, and the highest TPS of ordinary transactions reaches 30,000+, which is enough to cope with application scenarios such as government, finance, medical care, and industrial Internet.

In addition, in the public chain, all information is open and transparent and can be checked, and each participant is relatively equal.

However, in commercial applications and government services, there is a large amount of public-to-public data that needs to be encrypted, and there are also various organizational models in enterprises that need to set permissions. It is difficult for public chains to meet this complex demand.

In particular, my country's current policy has always advocated "no currency blockchain". Under the policy turmoil, the argument that "the alliance chain is the future of the blockchain" has become more and more "mainstream". Companies that have previously focused on the deployment of the alliance chain have begun to receive the attention of the government, capital and other parties, and their business cooperation and popularity have increased significantly. The public chains that have been overconsumed with the concept of "blockchain" have fallen into silence.

BAT giants such as Baidu, Ali, and Tencent have all entered the alliance chain one after another, giving birth to alliance chain giants such as "Super Chain", "Ant Chain", and FISCO BCOS, and explored in the fields of industry, people's livelihood, government affairs, and finance; at the same time, the alliance The chain track has also given birth to emerging alliance chain platforms such as PlatONE and BSN, which continue to promote the application practice of industrial blockchains.

The alliance chain is showing a trend of blooming everywhere and is expected to usher in great development.

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2. The implementation of alliance chain

In alliance chain application scenarios, such as inter-bank transfers, if the blockchain system is used to record transactions, although the strict and consistent ledger saves tedious reconciliation work, no bank wants to completely expose its capital transactions.

Moreover, from the perspective of policy orientation, countries have successively issued laws and regulations requiring the protection of user privacy. For example, the European Union implemented the GDPR (General Data Protection Regulation) in May 2018, which means that if companies in the European Union want to put users' personal data on the chain, they must ensure the privacy of the user data on the chain.

At present, most of the alliance chain solutions, although compared with the public chain, do have a certain degree of privacy protection. For example, some unauthorized nodes cannot view, upload, and verify data; but inside the alliance chain (that is, between nodes), most of the data is not fully protected, which also creates the possibility of data leakage under the chain .

Odaily found that in the past two years, some alliance chains have also explored and practiced privacy protection. In the following, we will first list cases in three typical scenarios so that readers can gain a perceptual understanding, and then introduce several mainstream solutions for privacy protection from a technical perspective.

(1) Financial scenarios: PlatONE, AntChain

Since its birth, the blockchain has been endowed with strong financial attributes and is inseparable from financial applications. However, in the financial implementation, there will also be many problems, such as the confirmation and settlement of all parties in the supply chain finance, the authenticity and availability of asset on-chain data, and so on. The financial solutions of "AntChain" under Ant Financial and "PlatONE" under Matrix Yuan deserve attention.

(Odaily Note: PlatONE is a new generation alliance blockchain platform based on privacy computing jointly created by Matrix Element and Wanxiang Blockchain, which supports industrial-grade applications. The platform proposes an industrial-grade Consortium chain infrastructure supports various demand scenarios such as finance and commerce, and has passed the function test and performance test "double test" of China Electronics Standardization Institute)

1. Digitization of vehicle assets

In traditional second-hand car transactions, due to the lack of a scientific and reliable residual value tracking and anchoring system, the price of a second-hand car is one, which varies from person to person, car to car, and location. For the sake of risk control, second-hand car service providers often tend to be conservative in closing prices, which makes the real value of vehicles always have deviations in transaction prices; and consumers who buy cars cannot fully understand the historical condition of second-hand cars, which reduces the demand for second-hand cars. Especially the willingness to buy high-end used cars.

• In addition, traditional OEMs can only guarantee maintenance records at 4S shops, and cannot completely record and verify all low- and high-frequency business information throughout the entire vehicle life cycle.

• In this regard, the MoveX vehicle asset digital management solution jointly released by PlatONE, Mercedes-Benz Xingrui Used Cars, Daimler Mobility Blockchain Factory, and Molian Technology will effectively motivate customers to pay attention to the entire life cycle of the car through the introduction of PlatONE+BoAT technology. The data of various low-frequency businesses within the company will be actively stored on the chain to ensure the accuracy and reliability of the vehicle condition, thereby increasing the residual value of the vehicle.

• 
  

  In terms of specific implementation, MBP (Mobility Blockchain Platform) builds a comprehensive technical infrastructure combining DID+IoT+Blockchain to continuously bring high-income returns at low cost and scale. The key technologies it adopts include:

Verify identity, credentials and signature based on DID technology;

Smart contracts based on privacy signatures;

Upload transaction records and invoices throughout the vehicle life cycle to the distributed blockchain for data storage anytime, anywhere, making it easier for financial institutions to obtain credible data for residual value assessment.

The vehicle data collected by T-Box is signed and stored on the blockchain, which ensures the credibility of the data collected during the entire life cycle of the vehicle at the source, and greatly reduces the possibility of forging or tampering with the life cycle portrait of the vehicle in the second-hand car transaction. These credible data on the chain are not only the twins of the vehicle's physical assets on the chain, but also can be combined with the Rosetta privacy AI framework technology of the matrix element to fully mine its data value under the premise of protecting privacy, so that data elements can be effectively circulated. Play greater commercial value and social value.

2. Blockchain Equity

Before equity transactions, investors need to conduct detailed background checks on the corresponding companies. However, some companies have complicated equity and chaotic management models, and it is difficult for investors to fully grasp the information; moreover, some companies will deliberately hide relevant information, giving equity The deal creates great uncertainty and erodes investor confidence.

In addition, the equity transaction process is cumbersome, involves multiple transactions, and takes a long time. Any error in any link will directly affect the income of investors, and it is also not conducive to the business development of related companies.

For equity registration, based on PlatONE, the timely registration, confirmation and maintenance of corporate equity information can be realized, and the threshold for institutional docking can be reduced through a distributed architecture, real-time security sharing of equity data can be realized, and the accuracy and transparency of important information disclosure can be guaranteed, providing enterprises with more Support for convenient and efficient financial services.

The equity registration and inquiry platform based on PlatONE can provide enterprises and shareholders with reliable equity registration, change and transaction modes, and supports the connection with industrial and commercial and information service agencies, improving the efficiency and credibility of off-site equity registration and maintenance.

3. Supply chain finance

Ant Financial's "Ant Chain" has always been at the forefront in the practice of supply chain finance.

As early as August 2019, Ant Financial and Bank of Chengdu cooperated to use blockchain technology to transform traditional supply chain finance and created a "dual-chain communication" model. The supply chain collaboration network based on blockchain technology - Ant Blockchain "Double Chain Link" has been fully upgraded and opened. This model has taken the lead in Chengdu.

Under the innovative model of "Double Chain Link", after the core enterprise is "on-chain", the buyer's real transaction background together with the payment commitment will generate a receivable certificate, which will become a transferable and financing asset after being claimed by the seller. The bank scans the information on the supply chain to know which large enterprise's product line the order is ultimately supplied to, knows that the borrowed money will flow to the normal supply of the main business, and knows that the borrower has the ability to repay.

At present, more than 30,000 enterprises have obtained financing services on this platform.

(2) Government affairs: open source view technology, FISCO BCOS

Government services are the main direction of many alliance chains, but they have encountered difficulties in promotion in actual implementation. The main reasons are as follows:

One is that different government departments have different business logics. In the government affairs system, different government departments undertake different functions, such as taxation, environmental protection, medical care, etc., and the processing logic of government affairs data is also different, which is determined by the government management system of our country.

For example, the public security department will register residents' personal identity information, but this involves citizens' privacy. If all these private data are released on the chain, once a large-scale privacy leak occurs, it will inevitably violate the vital interests of citizens. Even if it is not leaked by the public security department, it is difficult to escape accountability. It is the issue of power and responsibility and the existence of various hidden dangers that form a barrier and hinder the sharing of data among various government departments.

The second is that the data is redundant, which affects the operation of nodes. The consortium chain requires each node to store all the data, which can avoid "single point of failure", but it will greatly affect the efficiency in actual operation.

1. Blockchain license

This year, Sichuan Kaiyuanguan Technology Co., Ltd. cooperated with Dujiangyan City to issue the first blockchain real estate certificate and blockchain business license in Sichuan.

Previously, users had to bring their original ID card and household registration book to apply for a real estate title certificate, and usually had to be present in person to facilitate staff review. The real estate registration center also needs to connect information with taxation, public security, civil affairs and other departments to verify the authenticity of the information. The whole process is not only cumbersome, but also time-consuming.

Now, users do not need to carry a lot of paper materials, because ID cards, household registration books and other documents have already been stored in public security systems; The government blockchain network verifies the authenticity of relevant materials and directly issues blockchain real estate certificates to users.

In addition, blockchain certificates such as real estate title certificates and business licenses will also be stored as encrypted data for users to handle other businesses. In this pilot project, Dujiangyan Zangzhentang Traditional Chinese Medicine Clinic successfully applied for the country's first blockchain medical institution practice license by uploading blockchain real estate certificates, business licenses and other materials, after automatic system verification and manual review. for the record.

This also means that once the blockchain-based real estate title certificate and business license are launched, they can be used to support subsequent richer government affairs.

2. Health code

In the context of epidemic prevention and control, health codes have become a necessity for life and travel. However, in cross-border scenarios, the differences in the legal systems of Guangdong and Macao make cross-border mutual recognition of health codes a major difficulty.

In May 2020, the "Yuekang Code" and "Macau Health Code" mutual recognition system developed based on the domestic alliance chain platform FISCO BCOS was officially launched. As of December 17, 2020, the system has served more than 38 million customs clearance.

Chen Weijie, the project director of Macau Wangao Information Technology Co., Ltd., the technical supporter of the Guangdong-Macao Health Code Cross-border Mutual Recognition System, shared a set of data that shows that blockchain technology can support large-scale applications. At present, more than 350,000 people a day Using Guangdong-Macao transcoding, more than 110 million pieces of data have been uploaded to the chain.This system converts the health code information into encrypted and verifiable digital certificates, so that the institutions in Guangdong and Macao can still verify the authenticity of the information even if the background is not connected. When the user needs to verify the health code across borders, there is no need to repeatedly fill in the information on multiple platforms, and the system will automatically transcode for the user after obtaining authorization.(3) Anti-counterfeiting traceability: Fengsu

With the spread of the concept of blockchain, the open, transparent and non-tamperable technical characteristics of blockchain have begun to attract attention. People want to use blockchain technology to realize product traceability, so as to ensure the authenticity and safety of products. Currently, including Jingdong,

Ant Financial

Enterprises including China and Taiwan have entered the blockchain traceability industry one after another.

Based on SF's existing cross-border supply chain for overseas commodities, Fengsu has built a whole-process traceability system to monitor the entire process of commodity production, packaging, logistics, warehousing, customs declaration, inspection, sales, etc., and register information at each stage chain. In offline stores, consumers can scan the traceability QR code on the product to obtain product introduction information in Chinese, brand company information, third-party quality inspection report, product entry declaration information and whole-process logistics information, etc.

However, the traceability of the blockchain has been questioned, that is, how to ensure the authenticity of the "on-chain" information? Data entry is done manually and can easily be modified. If the authenticity of the "on-chain" information cannot be resolved, the so-called traceability is like empty talk.

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public chain

3. Technical Analysis: How to protect privacy?

In terms of privacy protection, the public chain provides a lot of ideas for the alliance chain, which is worth learning from.

public chain

Corda's solution to data privacy on the chain is to establish a consensus network only between parties who have the right to read the data, thus fundamentally avoiding the risk of data leakage.

Monero implements an encrypted hybrid scheme that does not depend on the central node through two key technologies: hidden address and ring signature. The hidden address is to solve the problem of the correlation of input and output addresses, and the ring signature is used to ensure the untraceability of the transaction address. In addition to the transaction address, the transaction amount will also reveal some privacy. Monero also provides a technology called Ring Confidential Transaction (RingCT) to simultaneously hide transaction addresses and transaction amounts.

In addition to the above solutions, homomorphic encryption is currently the most discussed solution in the industry. However, due to the noise problem, the current fully homomorphic encryption calculation depth is limited (can be understood as the number of multiplication calculations) and the key space is too large. Therefore, there is still a long way to go before commercial applications. An alternative to fully homomorphic encryption is semi-homomorphic encryption, that is, homomorphic encryption that only supports addition or multiplication, but there are not many scenarios where semi-homomorphic encryption can be implemented.

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"loose coupling"

"Loose coupling" is to leave the original government business logic and data in the application layer, and only compare the resulting information that needs to be transmitted in cross-departmental collaboration.

PlatONE

Specifically, using the blockchain certificate storage technology, the electronic certificates that have already been digitized are created and stored, and a string of password "digital fingerprints" are generated; each "digital fingerprint" corresponds to an original, and when it needs to be used, It is only necessary to compare whether the "digital fingerprint" is consistent with the original to know whether it is consistent with the original, without the need to transmit the original data.

At this time, blockchain technology only uses a plug-in or standard protocol to store "digital fingerprints" in a distributed manner. All departments and residents can use these "digital fingerprints" under certain standards and authorization. On this basis, data services based on the "digital fingerprint library" can be provided, the interface can be opened to third-party service companies, and innovation in open technology services can be encouraged in an open source and innovative way.

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After more than two years of research and development investment in blockchain underlying technology and cryptography, PlatONE has currently explored three main technical solutions: broadcast encryption + group signature; homomorphic encryption + zero-knowledge proof; secure multi-party computation (MPC) .

1. Broadcast encryption and group signature are used to solve the contradiction between individual privacy and central supervision.

The PlatONE consortium chain platform based on privacy computing integrates broadcast encryption and group signatures to realize that transaction request nodes can protect identity privacy in an anonymous manner while supporting management node review, and can designate multiple recipients to view encrypted content, which greatly improves Transaction privacy, traceability and flexibility.

2. Homomorphic encryption and zero-knowledge proof are used to solve the contradiction between transaction privacy and registration confirmation.

Matrix Element, together with top experts in cryptography from the Chinese Academy of Sciences and Wuhan University, conducted technical research, and launched a security solution combining homomorphic encryption and non-interactive zero-knowledge proof (NIZK) on the PlatONE consortium chain platform based on privacy computing. While using additive homomorphic ciphertext operations to protect transaction privacy, zero-knowledge proofs are used to ensure transaction validity. And a major breakthrough has been made in performance: millisecond-level delays, and light nodes such as smartphones can also generate proof processes.

By deploying the MPC nodes of each participating institution, each participating institution can collaboratively execute established logic calculations and output results without collecting and sharing local private data, and obtain comprehensive data portraits required by each other. In this way, cross-institutional and cross-industry data collaborative utilization can be formed to maximize the value of data.

In addition to the above solutions, some experts in the industry have proposed using channels (Channels), mixers (Mixers), etc. to solve the problem of data privacy protection in the blockchain.

In addition, the PlatONE consortium chain platform also supports various national secret algorithms such as SM2, SM3, and SM9 formulated by the State Cryptography Administration, further enhancing the commercial capabilities of privacy protection. No matter what kind of solution, like the blockchain technology itself, it is still in the early stage, and requires continuous technology research and development and investment, continuous optimization and improvement, in order to truly realize large-scale application.

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4. Summary: the public chain is to the left, and the alliance chain is to the right