Professor Cai Wei-de of Beihang University: How did we create a blockchain with a transaction frequency of over 8,000 times per second? | GAIR 2017

CCF-GAIR provides a broad communication platform for domestic and international academic and industry experts, which not only grasps the pulse of global artificial intelligence trends at a macro level, but also deeply explores the application and practical details of artificial intelligence in each vertical field.

Continuing the top guest lineup of the previous conference, this CCF-GAIR 2017 will welcome more heavyweight experts in the artificial intelligence and robotics industries. In the coming days, Leifeng.com will release guest introductions one after another. Today, we would like to introduce the guest of the Fintech Special Conference - Cai Wei-de, Director of the Digital Society and Blockchain Laboratory of Beihang University (hereinafter referred to as "Beihang Blockchain Laboratory") and Chief Scientist of Tiande Technology.

Guest Profile

Professor Wei-Tek Tsai is a distinguished professor of the National Thousand Talents Program, director of the Blockchain Laboratory of Beihang University, and chief scientist of Tiande Technology. He received a bachelor's degree in computer science from the Massachusetts Institute of Technology (MIT) in 1979 and a doctorate in computer science from the University of California, Berkeley in 1985. Since then, he has taught in the computer science departments of the University of Minnesota and Arizona State University for more than 30 years, and has trained more than 80 doctoral students.

Professor Cai Wei-de's research areas include service computing, software engineering, cloud computing, crowdsourcing and blockchain. In recent years, he has published 585 papers in international journals such as IEEE Transactions, Communications of the ACM, IEEE Computer, IEEE Software, and international conferences such as ICSM, QSIC, and COMPSAC, with 10,132 citations. He also holds two US patents (OUTER LOOP VECTORIZATION, USA, 5802375, 1998-9-1 and APPARATUS FOR VISUAL PROGRAMMING WITH SCREEN FLOW, USA, 6055369, 2000-4-25). In addition, he has served as the chairman or program committee chairman of international conferences such as COMPSAC, HASE, and WORDS.

In addition to his academic achievements, Professor Cai Wei-de's research has also been recognized and applied by many institutions in many countries, including the U.S. Department of Defense, Guidant, Intel, Cray Research, US WEST, Fujitsu, Hitachi, etc. Representative examples include: based on network security research, he developed an economic software test execution framework for Intel and deployed two base station controllers; based on his work in software maintenance, he designed a Y2K software maintenance test product for Fujitsu.

Breakthrough of Beihang Chain

Founded in October 2015, the Beihang Blockchain Laboratory is dedicated to the research and application of blockchain, smart contracts, computational law and digital society. Led by Cai Wei-de, the laboratory brings together a group of researchers from universities including Beihang University, Tsinghua University, Peking University, and consultants from industry, academia and research at home and abroad, including academicians of the American Academy of Engineering and experts from the German Central Bank.

As a representative experimental permission chain, Professor Cai Wei-de told Leiphone.com (official account: Leiphone.com) that Beihang Chain is currently focusing on basic research such as consensus algorithms, application issues, and architectural issues, with a focus on big data blockchain and high concurrency.

“Most people think that blockchain is all about security and consensus, but we believe that the biggest direction of blockchain is architecture and database, which contains endless problems. Unlike others who study smart contracts and serial blockchains, our research focuses on big data blockchains and high concurrency, and we do parallel work. These are two completely different directions, the difference is like that between a bicycle and a car.”

The issue of transaction frequency has always been one of the difficulties in the development of blockchain. For example, the peak transaction rate of Bitcoin is 7 transactions per second. Compared with VISA, which can process more than 20,000 transactions per second, and Alipay, which reached a peak of 120,000 transactions per second during the Double Eleven shopping festival last year, most blockchains at this stage cannot meet people's growing financial needs and can only complete low-frequency transactions. At the same time, there are news reports from time to time that the transaction frequency of some blockchains has exceeded 1,000 or 10,000, which shows that the industry is actively promoting related research.

Beihang Blockchain Laboratory is also one of them. In July 2016, the laboratory announced that the transaction speed of Beihang Chain exceeded 40,000 transactions per second. In a previous interview with the media, Professor Cai Weide said that this technological breakthrough only means that transaction frequency is no longer the most important issue for blockchain applications. However, there are many other obstacles on the road to commercialization, such as technical issues such as software application architecture, database, security, scalability and stability, as well as legal supervision issues.

Permission chain outside the laboratory

Any technology will only have real value after it is put into practical application. In addition to being the director of the Blockchain Laboratory of Beihang University, Professor Cai Weide also serves as the chief scientist of Tiande Technology. Tiande Technology was founded in August 2016 and focuses on the innovation and development of load-balanced permission chains (private chains, alliance chains, enterprise chains and all other non-public chains).

It is reported that Tiande Blockchain uses dual-chain (TBC-ABC) concurrent technology and parallel Byzantine protocol (CBFT) to support high-frequency transactions and improve scalability.

• The ABC (account chain) in the dual-chain architecture is responsible for maintaining account information, while the TBC (transaction chain) is responsible for executing transactions and maintaining transaction history. Blockchain computing can be divided or combined to achieve load balancing. The purpose of this design is to protect privacy, improve scalability, and save a lot of computing power. For more details, see Professor Cai Wei-de's article "A System View of Financial Blockchains" published in 2016.

• Compared with the traditional Byzantine protocol (PBFT), PBFT adopts a serial method, the height is determined when the block is built, and the relationship between transactions and blocks is highly related. In CBFT, transactions and voting are executed in parallel, the height is determined when the voting is completed, and the relationship between transactions and blocks is related.

Based on the above technologies, Tiande Technology has developed a big data version of the blockchain "Gaoxin No. 1". The big data platform is fully integrated into the blockchain architecture. 100% of the data comes from the blockchain, the data is correct, and real-time supervision is carried out. Application scenarios include exchanges, clearing houses, banks, and regulatory agencies. According to Tiande, Gaoxin No. 1 has been applied to the field of commodity clearing and settlement, and is negotiating some cooperation with Guizhou Financial Holdings.

On May 27, Tiande Technology released the "Dataledger Big Data Blockchain Platform". Professor Cai Weide mentioned that Gaoxin No. 1 runs for 4 to 8 hours every working day, with a transaction frequency of more than 4,000 times per second, and the speed of Shuanglong Digital Chain has exceeded 8,000tps.

Tiande Chain was born out of Beihang Chain. Professor Cai Weide said that Tiande Chain's dual-chain architecture, consensus algorithm, theory, etc. are not much different from Beihang Chain, but when the system was actually built, many unexpected problems occurred. Therefore, the algorithm has undergone a major change and has been iterated for three generations.

He pointed out that there were two real difficulties encountered during the implementation process.

“First, blockchain practitioners do not have a deep enough understanding of the financial industry, and they still need a period of adjustment. Second, some people may think that they can “slow down their demands and slow down their research” on blockchain, but in fact, there is still a great demand for the speed of blockchain.”

Seeing the future from now

When observing the current blockchain industry, it is easy to find a phenomenon - a variety of alliances. In this regard, Professor Cai Wei-de said that the alliance is a practice where the winner sets the standard, but it is difficult for the winner to emerge from within.

He explained that alliances have their role, but alliances may need to share a real blockchain or platform to function better. Otherwise, the organizations within the alliance will be more competitive and may not necessarily achieve anything.

In addition, it is interesting that although Professor Cai Wei-de is involved in the application process of blockchain, he believes that the current industry is too commercialized, causing some bad things to be over-hyped. As an integrated innovative technology, the basic research of blockchain needs to be more in-depth and solid. Professor Cai also admitted that under the current situation, it is not completely clear what blockchain practitioners do. But what is certain is that technology and platforms will continue to develop in the future, and blockchain will have a place in the changing financial market.

Finally, when talking about the new trend of blockchain, Professor Cai Wei-de believes that blockchain Internet will become a new trend. Previously, the industry may have believed that a chain could go all over the world, but in fact it is unlikely. Just as the Internet has various local area networks and wide area networks, there will be many blockchains in the future, so it is necessary to organize a blockchain Internet to facilitate the interaction between chains.

“It involves a wide range of aspects, including technology (such as the new TCP/IP protocol and the new version of ISO 20022 that can be supported by blockchain), business, alliances, countries, and even grassroots forces, but the rules of the blockchain Internet are currently blank. Multi-chain architecture will be the mainstream in the future, and the interoperability and network design of blockchains will promote a major reshuffle of the industry.”

Want to learn more about high-concurrency blockchain? Want to have an in-depth exchange with Professor Cai Wei-de? Come and attend the "Global Artificial Intelligence and Robotics Summit" (CCF-GAIR) on July 7-9! At that time, Professor Cai will share two aspects of technology and application at the Fintech sub-venue. You can enjoy a 40% discount when you buy tickets now ! Click "Read the original text" to enjoy another 800 yuan discount on top of the 40% discount. Oh~