Summary
In recent years, blockchain has become a research hotspot in the field of Internet finance. As a distributed ledger technology, the blockchain has many advantages such as decentralization, non-tampering, security and credibility, but at the same time it faces problems such as high energy consumption and low throughput. As the core of the blockchain, the consensus algorithm determines the way the blockchain reaches consensus and generates blocks. The Practical Byzantine Consensus Algorithm (PBFT) is currently the most widely used consensus algorithm in the consortium blockchain. It has the advantages of low energy consumption and high throughput, but it has defects such as high bandwidth requirements and a fixed number of nodes.
Research Background
Blockchain is a decentralized or strictly speaking, a multi-centralized distributed database system. Each node in the blockchain stores all transaction records or the hash value of its transaction record Merkle tree. The system is composed of a series of data blocks that are encrypted and compressed using cryptography methods and then linked in an orderly manner. Since the hash value of the merkle tree of the previous block is included in the next block, the content in each block cannot be tampered with by others within a certain period of time.
At present, the blockchain has developed into three differentiated types: public chain, alliance chain, and private chain.
- The public chain is represented by Bitcoin, and all transaction data on the public chain is public, so everyone can verify the data on the public chain. It can be seen from this that the public chain is a completely distributed and decentralized system with high user participation.
- Consortium chain, as the name suggests, the nodes participating in it are all selected in advance, and there are certain connections and relationships between them. Compared with the public chain, due to the relatively fixed number of participating nodes and the better credit of the nodes in the alliance chain, the transaction speed is faster, the cost is lower, and the energy consumption of the transaction is also smaller.
- The private chain has fewer nodes involved, such as some specific organizations. It can be seen from this that the private chain is contrary to the essence of the blockchain, but it can meet the application of some scenarios.
Influenced by programmable currency, major banking institutions are exploring how to apply blockchain technology to the financial industry. People are experimenting with applying the concept and technology of smart contracts to the blockchain, thus further forming a programmable financial model.
At present, the characteristics of "data anti-counterfeiting" and "decentralization" in the blockchain have been widely valued in various fields. Blockchain can be applied in arbitration, traceability, logistics, voting and other fields. As a result, the entire society has entered the era of intelligent Internet, making the blockchain not only reduce the cost of trust in financial currency, but also be used in other fields. Thus forming a programmable society.
With the rapid development and widespread use of Internet technology, many people believe that blockchain will be the "next Internet". It can be seen that people are very optimistic about the development of blockchain technology. At present, universities, banks, and IT companies all over the world are investing manpower and material resources in the research of blockchain. A next-generation Internet that redefines trust is coming.
Research Status Abroad
At present, Bitcoin and the different digital currencies derived from it are still the main research and application objects of blockchain. After the major Internet, IT and other enterprises set foot in the blockchain, they began to study and push the blockchain technology to the financial field, and finally applied the blockchain to all walks of life in daily life. Currently, the Ripple protocol launched by Ripple hopes to become a next-generation payment protocol, making it as convenient as communication. The Ripple currency launched by it has also attracted more and more people's attention around the world. In addition, blockchain has a wide range of applications in other areas. Follow My Vote has developed blockchain online voting software. This voting software is different from traditional voting software, it is a share-weighted voting software. At the same time, the software uses blockchain technology as its underlying layer, which can ensure that voters' votes cannot be tampered with and candidates' votes cannot be changed. The result of the final vote cannot be changed, and the result is open to all users on the blockchain, so whether it is correct or not can be easily queried. It can thus be said that this voting software can make voting more fair and open.
IBM has launched a blockchain project that can trace the origin of food, IBM FoodTrastIBM believes that participants in the food industry need to see their supply chain from a credible, end-to-end point of view, and they also need to see the transparency of the entire industry in Increasing. Food can be traced throughout the entire system of the food supply chain to ensure food safety. And at the same time, it can detect and track pollution faster. In this way, suppliers, distributors, logistics providers, etc. in the food chain are transparent to the outside world in every step of operation, so that final consumers can benefit from it. Through the ffiM FoodTmst solution, if there is a problem with food safety, suppliers and retailers can quickly and efficiently track and recall products. This solution provides food supply chain participants with a permissioned, shared view of food industry information. With blockchain technology at the core of its digital strategy, the food industry has the opportunity to respond to existing health risks quickly, efficiently, and accurately. Thereby greatly improving video security. So far, IBM has signed contracts with many companies to put this project into practical use.
Research state in China
According to the "China Blockchain Technology and Application Development White Paper" issued by the Ministry of Industry and Information Technology, it can be sorted out that blockchain technology is not equal to digital currency, so it is necessary to distinguish blockchain technology from digital currency. The state strongly supports the development of blockchain technology, and the management of digital currency will not be relaxed in a short time.
Unlike the western world, which focuses on the development of blockchain in the ICO field, due to the strict monitoring of domestic regulatory authorities, my country focuses more on the research on the application of blockchain.
Blockchain research can be mainly divided into blockchain side chain and cross-chain research, blockchain application research, blockchain smart contract research, blockchain consensus algorithm improvement and scalability research, research on node data transmission performance in blockchain, security research on blockchain technology, etc.
Smart contract technology has once again appeared in front of people's eyes due to the emergence of blockchain technology. However, the current instability and security issues of smart contract technology require further research before it can be truly applied in real life. . The consensus algorithm, security, scalability, and node data transmission performance of the blockchain are all aimed at improving the blockchain itself, so that the cross-chain can better serve us.
Blockchain core technology
blockchain database
The blockchain is a multi-centralized distributed ledger. Each node in the blockchain is equivalent to a database in a distributed system. However, it is different from a distributed database in that there is no central administrator to maintain each node. Data synchronization between databases. However, in the blockchain, data can only be written into the database of the block, and cannot be deleted or modified. Various cryptography techniques are used in the blockchain to ensure the security of the data stored in the block. And the blockchain is a distributed system, tampering with the data of a node will not be recognized by most nodes in the system, and it is just futile. This distributed database server cluster is distributed in order to achieve service recovery and backup, data redundancy, and so on. However, their knowledge still belongs to a certain enterprise or institution, so they are still centrally managed database clusters.
However, since the data on the blockchain is distributed and encrypted by cryptography, neither the uploader of the data nor the storage of the data can know the specific storage location of a certain data. This can prevent illegal content from polluting the blockchain database.
distributed ledger
A blockchain is a distributed ledger with specific technologies, but not all distributed ledgers are blockchains.
- Distributed ledgers are as decentralized as blockchains at the technical level, and consensus algorithms are also used to keep data between ledgers. Although the consensus algorithm used is different, this is because the traditional distributed ledger does not need to consider the Byzantine problem.
- The traditional ledger structure has an organization to manage all the ledger data on the system, so this distributed ledger does not seem to be a decentralized system in the true sense.
In the blockchain, what we want to achieve is a complete, 100% decentralized, distributed ledger where each node manages its own local ledger data.
- In this system, no one organization can manage most of the node ledgers.
- Each ledger is connected together through hash function and timestamp technology.
- The bifurcation phenomenon in Bitcoin is caused by the competition among various miners in the Bitcoin community.
This is a healthy competition, which shows that no one institution in the Bitcoin system can control all nodes on the blockchain.
consensus algorithm
POW and POS algorithms are currently the most widely used consensus algorithms in public chains. Currently well-known applications such as Bitcoin and Ethereum all use POW algorithm or POS algorithm. The following conclusions can be drawn about the performance of the POW algorithm and the POS algorithm after consulting the Bitcoin and Ethereum data:
It is currently recognized that the consensus algorithm of the blockchain can be improved according to the usage scenarios of the blockchain from the aspects of high throughput, low energy consumption, and dynamics of the system.
research direction:
Blockchain research can be mainly divided into blockchain
- Sidechain and cross-chain research,
- Application research of blockchain,
- Research on smart contracts in blockchain,
- Research on the improvement and scalability of the consensus algorithm in the blockchain,
- Research on node data transmission performance in blockchain,
- Security research on blockchain technology, etc.
Among them, side chains and cross-chains are mainly to solve the problems of performance , capacity , privacy and the inability to transfer data between chains in the current single-chain situation . The application research of blockchain is the most popular direction of blockchain research at home and abroad . At present, the combination of blockchain technology and various industries in various fields can greatly increase the efficiency of various industries, which has attracted the attention of many people.
Smart contract technology has once again appeared in front of people's eyes due to the emergence of blockchain technology. However, the current instability and security issues of smart contract technology require further research before it can be truly applied in real life. . The consensus algorithm, security, scalability, and node data transmission performance of the blockchain are all aimed at improving the blockchain itself, so that the cross-chain can better serve us.