Blockchain is an important concept of Bitcoin. It is essentially a decentralized database. At the same time, as the underlying technology of Bitcoin, it is a series of data blocks related by cryptography. Each data block contains the information of online transaction of Bitcoin, which is used to verify the validity of the information (anti-counterfeiting) and generate the next block.
meaning
In a narrow sense, blockchain is a chained data structure that combines data blocks in chronological order, which is cryptographically guaranteed to be an unbreakable and unforgeable distributed account book.
blockchain
Broadly speaking, blockchain technology is a brand-new distributed infrastructure and computing method. It uses blockchain data structure to verify and store data, uses distributed node identification algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contracts composed of automated script codes to program and manipulate data.
Infrastructure model
Blockchain infrastructure model
Generally speaking, the blockchain system consists of data layer, network layer, knowledge layer, incentive layer, contract layer and application layer. Among them, the data layer encapsulates the underlying data block and related basic data and algorithms such as data encryption and timestamp; The network layer includes distributed networking mechanism, data distribution mechanism and data verification mechanism. * * * knowledge layer mainly encapsulates all kinds of * * * knowledge algorithms of network nodes; The incentive layer integrates economic factors into the blockchain technology system, mainly including the distribution mechanism and distribution mechanism of economic incentives; The contract layer mainly encapsulates various scripts, algorithms and intelligent contracts, which is the basis of the programmable characteristics of blockchain; The application layer encapsulates various application scenarios and cases of blockchain. In this model, the blockchain structure based on timestamp, the * * * knowledge mechanism of distributed nodes, the economic incentive based on * * * knowledge and the flexible and programmable intelligent contract are the most representative innovations of blockchain technology. .
Brief introduction of blockchain core technology
Blockchain mainly solves the trust and security problems of transactions, so four technological innovations are proposed to solve this problem:
The first type is called distributed ledger, which means that transaction bookkeeping is completed by multiple nodes distributed in different places, and each node records complete accounts, so everyone can participate in supervising the legality of transactions and testify for them.
Different from traditional distributed storage, the uniqueness of blockchain distributed storage is mainly reflected in two aspects: first, each node of blockchain stores complete data according to blockchain structure, while traditional distributed storage generally stores data in multiple parts according to certain rules. Second, the storage of each node in the blockchain is independent and has the same state, and the consistency of storage is guaranteed by the * * * knowledge mechanism, while the traditional distributed storage generally synchronizes data with other backup nodes through the central node.
No node can record account book data independently, thus avoiding the possibility that a single bookkeeper is controlled or bribed to record false accounts. Because there are enough accounting nodes, theoretically, unless all nodes are destroyed, the account will not be lost, thus ensuring the security of account data.
The second is called asymmetric encryption and authorization technology. The transaction information stored in the blockchain is public, but the account identity information is highly encrypted and can only be accessed with the authorization of the data owner, thus ensuring the security of data and personal privacy.
The third is called * * * knowledge mechanism, which is how to realize * * knowledge among all accounting nodes to identify the validity of a record. This is not only a means of identification, but also a means to prevent tampering. Blockchain proposes four different * * * sensing mechanisms, which are suitable for different application scenarios and strike a balance between efficiency and security.
The * * * knowledge mechanism of blockchain has the characteristics of "minority obeys the majority" and "everyone is equal", in which "minority obeys the majority" does not completely refer to the number of nodes, but also can be the computing power, share number or other comparable characteristic quantities of computers. "Everyone is equal" means that when the nodes meet the conditions, all nodes have the priority to obtain the * * * knowledge result, which may become the final * * * knowledge result after being directly recognized by other nodes.
Take Bitcoin as an example, and adopt workload proof. Only when more than 5 1% accounting nodes in the whole network are controlled, it is possible to forge a nonexistent record. When enough nodes join the blockchain, this is basically impossible, thus eliminating the possibility of fraud.
The last technical feature is called smart contract, which can automatically execute some predefined rules and terms based on these credible and tamper-proof data. Taking insurance as an example, if everyone's information (including medical information and risk information) is authentic, it is easy to make automatic claims in some standardized insurance products.
In the daily business of insurance companies, although transactions are not as frequent as those in the banking and securities industries, they are increasingly dependent on trusted data. Therefore, the author believes that using blockchain technology from the perspective of data management can effectively help insurance companies improve their risk management capabilities. Specifically, it is mainly divided into risk management of policyholders and risk supervision of insurance companies.
Development course of blockchain
Blockchain-The original blockchain is a decentralized database, which contains a list called blocks, and the records are growing and arranged neatly. Each block contains a timestamp and a link to the previous block: the blockchain is designed so that the data cannot be tampered with-once recorded, the data in the block will be irreversible.
The design of blockchain is a protective measure, such as a highly fault-tolerant distributed computing system. Blockchain makes mixed consistency possible. This makes the blockchain suitable for recording events, titles, medical records and other activities that need to include data, identification management, transaction process management and origin certification management. Blockchain has great financial disintermediation potential and has great influence on guiding global trade.
The concept of blockchain was first put forward by Satoshi Nakamoto in 2008. In the following years, it became the core component of electronic currency Bitcoin: the public ledger of all transactions. By using peer-to-peer network and distributed timestamp server, the blockchain database can be managed independently. The blockchain invented for Bitcoin makes it the first digital currency to solve the problem of repeated consumption. The design of Bitcoin has become a source of inspiration for other applications.
199 1 year, Stuart Haber and W. Scott Stornetta first put forward the encryption protection chain product about blocks, followed by Ross J. Anderson and Bruce Schneider &；; John Cale West was published in 1996 and 1998 respectively. At the same time, Nick Szabo studied the decentralization mechanism of electronic money in 1998, which he called Bitkin. In 2000, Stefan Konst published the unified theory of encryption protection chain and proposed a set of implementation schemes.
Blockchain format, as a solution that can make the database secure without administrative agency credit, was first applied to Bitcoin. From June 5438 to October 2008 10, in Satoshi Nakamoto's original papers, the words "block" and "chain" were used separately, but when they were widely used, they were collectively referred to as block-chain. It was not until June 20 16 that they became a word: "blockchain". In August of 20 14, the blockchain file size of bitcoin reached 20 gigabytes.
By 20 14, "blockchain 2.0" has become a term about decentralized blockchain database. For this second-generation programmable blockchain, economists believe that its achievement lies in "it is a programming language that allows users to write more complex and intelligent protocols, so when the profit reaches a certain level, they can benefit from the completed freight bill, or * * * can enjoy the dividend of the certificate". Blockchain 2.0 technology skips transactions and "acts as an intermediary for currency and information arbitration in value exchange". They are used to keep people away from the global economy, protect their privacy, make people "turn their information into money" and have the ability to ensure that the owners of intellectual property rights benefit. The second generation blockchain technology makes it possible to store personal "permanent digital ID cards and images" and provides a solution to the inequality of "potential social wealth distribution". 14-15 As of 20 16, transactions under blockchain 2.0 still need to pass through Oracle Bone Inscriptions, so that any "external data or events based on time or market conditions [really need] can interact with the blockchain".
In 20 16, the Central Securities Research Institute (NSD) of the Russian Federation announced a pilot project based on blockchain technology. Many institutions with regulatory power in the music industry have begun to use blockchain technology to build test models in order to collect royalties and manage copyrights on a global scale. 2065438+In July 2006, IBM opened the Blockchain Innovation Research Center in Singapore. On 20 16 1 1 year, a working group of the World Economic Forum held a meeting to discuss the development of the blockchain government governance model. According to Accenture's survey on the development of innovation theory, the utilization rate of blockchain in the economic field in 20 16 years was 13.5%, reaching the early development stage. In 20 16, the WTO * * * established the global blockchain forum, which is the predecessor of the e-commerce chamber of commerce.
This concept was put forward in Satoshi Nakamoto's white paper, and Satoshi Nakamoto created the first block, namely "creating block".
On June 38, 2009+10/October 3, Satoshi Nakamoto, the founder of Bitcoin, left a sentence in Chuangshi Block that will never be modified:
"Times 03/ 1/2009 The Finance Minister was on the verge of a second round of bank rescue (on June 38, 2009, the Finance Minister was on the verge of implementing a second round of bank emergency rescue)."
At that time, British Chancellor of the Exchequer Darling was forced to consider the second step to ease the banking crisis. This sentence was the title of the front page article of the Times that day.
The existence of timestamp service and blockchain proves that the time when the first blockchain was generated and the events that happened at that time were permanently preserved.
Bitcoin company BTCC launched a service "Millennium Chain" on 20 15, that is, blockchain lettering service, which adopted the above principles. Through this service, users can engrave words on the blockchain and save them permanently.
The present situation in digital currency is that a hundred flowers blossom. List some common ones: Bitcoin, Litecoin, dogecoin and dashcoin. In addition to the application of money, there are various derivative applications, such as Ethereum, Asch and other underlying application development platforms, as well as NXT, SIA, Bitstock, MaidSafe, Ripple and so on.
2065438+200665438+1On October 20th, the People's Bank of China digital currency Seminar announced that the research on digital currency had achieved initial results. The meeting affirmed the value of digital currency in reducing the issuance of traditional currency, and said that the central bank is exploring the issuance of digital currency. The statement made by the People's Bank of China in digital currency seminar greatly enhanced the confidence of digital currency industry. This is the first time that the five ministries and commissions of the Central Bank issued a notice on preventing bitcoin risks on February 5, 20 13, expressing a clear attitude towards digital currency.
Some areas where the blockchain can be used include:
Intelligent contract
securities trading
E-commerce/e-commerce
Internet of things
social communication
file storage
Proof of existence
certificate
crowdfunding
We can compare the development of blockchain with the development of the Internet itself. In the future, something called Finance-Internet will be formed on the Internet. This thing is based on blockchain, and its predecessor is Bitcoin, that is, traditional finance starts from private chain and industrial chain (local area network), and Bitcoin series starts from public chain (wide area network), all of which express the same concept-DigitalAsset, and finally converges to a middle equilibrium point.
The evolution of blockchain is:
Blockchain 1.0- digital currency
Blockchain 2.0- Digital Assets and Smart Contracts
Blockchain 3.0-Distributed Application in Various Industries