Blockchain is a term in the field of information technology. In essence, it is a shared database. The data or information stored in it has the characteristics of "unforgeable", "full trace", "traceable", "open and transparent", and "collective maintenance". Based on these characteristics, blockchain technology has laid a solid "trust" foundation, created a reliable "cooperation" mechanism, and has broad application prospects.
In the daily sharing process of Huobi Research Institute, I like to use this method to help everyone understand.
Blockchain technology can be understood as the "paper" of the information age. In the development of human civilization, the invention of paper is of great significance. It is a carrier of information and value. Paper can be written to carry information and printed into money to carry value. The blockchain is the "paper" of the information age, realizing information transmission and value transmission from a higher-dimensional standpoint. For example, the blockchain invoice supported by Tencent uses the blockchain paper as an invoice, while the STO currency issuing model represented by the United States uses the blockchain paper as a security.
If someone asks, since it is paper, why is paper like Bitcoin so valuable? The papyrus of ancient Egypt still exists today. If the papyrus of ancient Egypt is used as a collection, then such paper is naturally very valuable because it is scarce.
origin
The origin of the word "blockchain" is the "chain of blocks" in the original English version of the Bitcoin white paper. When the Chinese market translates this sentence, the word "blockchain" is directly used, and then the word is directly written as "Blockchain" has become a proper term for the entire global blockchain technology today.
Blockchain originated from Bitcoin. On November 1, 2008, a person who claimed to be Satoshi Nakamoto published an article "Bitcoin: A Peer-to-Peer Electronic Cash System", which explained that based on P2P network technology, The architectural concepts of electronic cash systems such as encryption technology, time stamp technology, and blockchain technology, which marked the birth of Bitcoin. Two months later, the theory entered practice, and the first creation block with serial number 0 was born on January 3, 2009. A few days later, a block with serial number 1 appeared on January 9, 2009, and it was connected with the genesis block with serial number 0 to form a chain, marking the birth of the blockchain.
This is like the invention of the atomic bomb. The original driving force for the development of this technology is military needs. As for what field nuclear energy will ultimately play a greater role in, this will not affect the meaning of the atomic bomb. If we compare blockchain to nuclear energy, Bitcoin is an atomic bomb, and physical applications are similar to nuclear power plants, nuclear-powered aircraft carriers, submarines, nuclear-powered icebreakers, and even nuclear-powered trucks.
No matter who is interpreting the blockchain, Bitcoin cannot be bypassed, just as if you want to introduce the history of cars, you can't bypass Karl Benz, and you can't bypass the Wright brothers if you want to introduce the history of airplanes. Bitcoin "invented" and confirmed the feasibility of the blockchain technology. Bitcoin is not the entire blockchain technology, but only one of its applications. Bitcoin uses blockchain technology.
Core technologies
The blockchain is essentially a series of data blocks that are associated with cryptography. Specifically, the result of a random hash algorithm. The only thing the blockchain does is to get some input and then perform calculations, and get a string A string of 64-bit random numbers and letters. Each data block contains valid confirmation information for multiple Bitcoin network transactions. The blockchain is composed of a series of non-repetitive data blocks.
For example: 000000000000084b6550604bf21ad8a955b945a0f78c3408c5002af3cdcc14f5
Blockchain infrastructure model
Generally speaking, the blockchain system is composed of data layer, network layer, consensus layer, incentive layer, contract layer and application layer. Among them, the data layer encapsulates the underlying data blocks and related data encryption and time stamping and other basic data and basic algorithms; the network layer includes distributed networking mechanisms, data propagation mechanisms, and data verification mechanisms; the consensus layer mainly encapsulates network nodes The incentive layer integrates economic factors into the blockchain technology system, mainly including the issuance mechanism and distribution mechanism of economic incentives; the contract layer mainly encapsulates various scripts, algorithms and smart contracts, which is a blockchain The basis of programmable features; the application layer encapsulates various application scenarios and cases of blockchain.
In this model, the chain block structure based on timestamp, the consensus mechanism of distributed nodes, the economic incentive based on consensus computing power and the flexible and programmable smart contract are the most representative innovations of blockchain technology.
Distributed ledger
Distributed ledger means that transaction accounting is completed by multiple nodes distributed in different places, and each node records a complete account, so they can participate in monitoring the legality of transactions, and they can also jointly testify for it.
Different from the traditional distributed storage, the uniqueness of the distributed storage of the blockchain is mainly reflected in two aspects: one is that each node of the blockchain stores complete data according to the blockchain structure, and the traditional distributed storage Generally, the data is divided into multiple parts for storage according to certain rules.
The second is that the storage of each node of the blockchain is independent and equal in status. It relies on the consensus mechanism to ensure the consistency of storage, while traditional distributed storage generally synchronizes data with other backup nodes through the central node. No single node can record the book data separately, thus avoiding the possibility of a single bookkeeper being controlled or bribed to keep false accounts. There are also enough accounting nodes. In theory, unless all nodes are destroyed, the account will not be lost, thus ensuring the security of the account data.
Asymmetric encryption
The transaction information stored on the blockchain is public, but the account identity information is highly encrypted and can only be accessed under the authorization of the data owner, thus ensuring data security and personal privacy.
Consensus mechanism
The consensus mechanism is how to reach a consensus between all bookkeeping nodes to determine the validity of a record. This is not only a means of identification, but also a means of preventing tampering. Blockchain proposes four different consensus mechanisms, which are suitable for different application scenarios and strike a balance between efficiency and security.
The consensus mechanism of the blockchain has the characteristics of "the minority obeys the majority" and "everyone is equal". The "minority obeys the majority" does not completely refer to the number of nodes, but can also be comparable to computing power, equity or other computers. Feature amount. "Everyone is equal" means that when nodes meet the conditions, all nodes have the right to give priority to the consensus result, and it may become the final consensus result after being directly recognized by other nodes. Take Bitcoin as an example. Proof of work is used. Only when more than 51% of the accounting nodes in the entire network are controlled, it is possible to forge a non-existent record. When enough nodes are added to the blockchain, this is basically impossible, thereby eliminating the possibility of fraud.
Smart contract
Smart contracts are based on these credible and non-tamperable data, which can automatically execute some pre-defined rules and terms, allowing credible transactions without a third party, and these transactions are traceable and irreversible. The concept of smart contracts was first proposed by Nick Szabo in 1995. The purpose of smart contracts is to provide a safer method than traditional contracts and reduce other transaction costs associated with the contract.
feature
Decentralization. Blockchain technology does not rely on additional third-party management agencies or hardware facilities, and there is no central control. Except for the self-contained blockchain itself, through distributed accounting and storage, each node realizes information self-verification, transmission and management. Decentralization is the most prominent and essential feature of blockchain.
Openness. The foundation of the blockchain technology is open source. Except that the private information of all parties to the transaction is encrypted, the data of the blockchain is open to everyone. Anyone can query the blockchain data and develop related applications through the public interface. System information is highly transparent.
Independence. Based on consensus specifications and agreements (similar to various mathematical algorithms such as the hash algorithm used by Bitcoin), the entire blockchain system does not rely on other third parties, and all nodes can automatically and securely verify and exchange data in the system without Any human intervention.
safety. As long as you cannot control 51% of all data nodes, you cannot control and modify network data arbitrarily. This makes the blockchain itself relatively safe and avoids subjective and artificial data changes.
Anonymity. Unless required by laws and regulations, technically speaking, the identity information of each block node does not need to be disclosed or verified, and information can be transferred anonymously.
Types of
Public blockchain
Public Block Chains refer to: Any individual or group in the world can send transactions, and transactions can be effectively confirmed by the blockchain, and anyone can participate in the consensus process. The public blockchain is the earliest blockchain and the most widely used blockchain. The virtual digital currencies of the major bitcoins series are all based on the public blockchain. There is and only one blockchain corresponding to this currency in the world. .
Alliance blockchain
Consortium Block Chains: multiple pre-selected nodes are designated as bookkeepers within a certain group, the generation of each block is determined by all pre-selected nodes (the pre-selected nodes participate in the consensus process), and other access nodes You can participate in transactions, but you don’t need to ask about the bookkeeping process (essentially, it’s still custodial bookkeeping, it just becomes distributed bookkeeping, how many pre-selected nodes, how to determine the bookkeeper of each block becomes the main risk point of the blockchain) , Anyone else can perform limited queries through the open API of the blockchain.
Private blockchain
Private Block Chains: Only use the general ledger technology of the blockchain for accounting. It can be a company or an individual, and has exclusive access to the blockchain. This chain and other distributed The storage scheme is not much different. Traditional finance wants to experiment with private blockchains, while public chain applications such as bitcoin have been industrialized, and private chain application products are still being explored.