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Blockchain is completely unchangeable
Publish: 2021-04-27 20:59:00
1. First, the characteristics of decentralization
as the name suggests, a blockchain does not need a centralized server, and all information is stored on each node in the chain in a distributed form. Even if a node is damaged or tampered, the operation of the whole blockchain will not be affected, and the data will not be disordered
Second, consensus mechanism
consensus mechanism plays an important role in the trustworthiness of data on blockchain. Due to the decentralized architecture, any two nodes in the chain do not need to trust each other's identity to establish a connection, and there is no need to trust each other for data exchange. Since all nodes in the network can act as "supervisors", there is no need to worry about fraud. When a transaction is completed, all nodes on the blockchain will synchronize this information, so the consensus mechanism is based on the distributed architecture to ensure the data can not be tampered with
Third, smart contract
before we talk about blockchain + smart contract, let's first clarify the meaning of smart contract: a set of commitments defined in digital form, on which contract participants can implement these commitments. Generally speaking, it is a smart contract. In a computer system, when certain conditions are met, the contract can be executed automatically.
as the name suggests, a blockchain does not need a centralized server, and all information is stored on each node in the chain in a distributed form. Even if a node is damaged or tampered, the operation of the whole blockchain will not be affected, and the data will not be disordered
Second, consensus mechanism
consensus mechanism plays an important role in the trustworthiness of data on blockchain. Due to the decentralized architecture, any two nodes in the chain do not need to trust each other's identity to establish a connection, and there is no need to trust each other for data exchange. Since all nodes in the network can act as "supervisors", there is no need to worry about fraud. When a transaction is completed, all nodes on the blockchain will synchronize this information, so the consensus mechanism is based on the distributed architecture to ensure the data can not be tampered with
Third, smart contract
before we talk about blockchain + smart contract, let's first clarify the meaning of smart contract: a set of commitments defined in digital form, on which contract participants can implement these commitments. Generally speaking, it is a smart contract. In a computer system, when certain conditions are met, the contract can be executed automatically.
2. In one sentence, it is decentralization
blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies
the so-called consensus mechanism is a mathematical algorithm to establish trust and obtain interests between different nodes in the blockchain system
in a narrow sense, blockchain is a kind of chain data structure that combines data blocks in chronological order in a sequential way, and it can not be tampered with and forged by cryptography
broadly speaking, blockchain technology is a new distributed infrastructure and computing method, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data< Advantages:
1) the algorithm is simple and easy to implement
2) there is no need to exchange additional information between nodes to reach a consensus
3) it takes a lot of cost to destroy the system< Disadvantages:
1) waste of energy
2) it is difficult to shorten the block confirmation time
3) the new blockchain must find a different hash algorithm, otherwise it will face bitcoin attack
4) it is easy to generate bifurcation and needs to wait for multiple confirmations
5) there is no finality, and checkpoint mechanism is needed to make up for it.
blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies
the so-called consensus mechanism is a mathematical algorithm to establish trust and obtain interests between different nodes in the blockchain system
in a narrow sense, blockchain is a kind of chain data structure that combines data blocks in chronological order in a sequential way, and it can not be tampered with and forged by cryptography
broadly speaking, blockchain technology is a new distributed infrastructure and computing method, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data< Advantages:
1) the algorithm is simple and easy to implement
2) there is no need to exchange additional information between nodes to reach a consensus
3) it takes a lot of cost to destroy the system< Disadvantages:
1) waste of energy
2) it is difficult to shorten the block confirmation time
3) the new blockchain must find a different hash algorithm, otherwise it will face bitcoin attack
4) it is easy to generate bifurcation and needs to wait for multiple confirmations
5) there is no finality, and checkpoint mechanism is needed to make up for it.
3. Once the information is verified and added to the blockchain, it will be stored permanently. Unless more than 51% of the nodes in the system can be controlled at the same time, the modification of the database on a single node is invalid. Therefore, the data stability and reliability of the blockchain are extremely high.
4.
Blockchain is a kind of chain data structure that combines data blocks in order according to the time sequence, and it can't be tampered and forged by cryptography. In a broad sense, blockchain technology is a new distributed infrastructure and computing paradigm, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data< br />
5. Player 1: s key to put the hook, W key to throw explosives
player 2: key to put the hook, W key to throw explosives.
player 2: key to put the hook, W key to throw explosives.
6. If it is the proof of workload, it can be modified, but it needs to invest a lot of money. For example, if you want to change the block data of bitcoin (such as transferring all bitcoin to your wallet, etc.), it needs to account for 51% of the total network computing power. But with so many miners digging, it is basically impossible to account for 51% of the total network computing power.
7. Blockchain technology has three obvious characteristics: openness, security and uniqueness
openness mainly refers to that the stored information in the blockchain is completely open to all participants. This is mainly determined by the point-to-point network storage mode of the blockchain. In the blockchain network, each node can store a of the blockchain, and the uniqueness of the blockchain can ensure that the is exactly the same between different nodes
security mainly refers to that the information stored in the blockchain block is saved after being processed by digital encryption technology, and only the private key holder can decrypt the information to obtain the real information. Other members can only see and verify the integrity and uniqueness of information, but cannot see the real information
uniqueness is mainly e to the fact that the information on the blockchain cannot be tampered with once it is on the chain, so it is unique. Of course, the uniqueness here also includes the uniqueness in space, that is, all nodes have only one version of information, and also includes the uniqueness in time, that is, the historical data cannot be changed. This uniqueness also means that the blockchain maintains the characteristics of a unique main chain in the process of operation, and once other chains appear, it is a bifurcation. The emergence of bifurcation will lead to the plication of blockchain in two different spatial dimensions. Of course, to solve this problem, we need to set reasonable consensus rules to avoid. When the concept of blockchain was hot, many related top domain names were registered and used as blockchain platforms.
openness mainly refers to that the stored information in the blockchain is completely open to all participants. This is mainly determined by the point-to-point network storage mode of the blockchain. In the blockchain network, each node can store a of the blockchain, and the uniqueness of the blockchain can ensure that the is exactly the same between different nodes
security mainly refers to that the information stored in the blockchain block is saved after being processed by digital encryption technology, and only the private key holder can decrypt the information to obtain the real information. Other members can only see and verify the integrity and uniqueness of information, but cannot see the real information
uniqueness is mainly e to the fact that the information on the blockchain cannot be tampered with once it is on the chain, so it is unique. Of course, the uniqueness here also includes the uniqueness in space, that is, all nodes have only one version of information, and also includes the uniqueness in time, that is, the historical data cannot be changed. This uniqueness also means that the blockchain maintains the characteristics of a unique main chain in the process of operation, and once other chains appear, it is a bifurcation. The emergence of bifurcation will lead to the plication of blockchain in two different spatial dimensions. Of course, to solve this problem, we need to set reasonable consensus rules to avoid. When the concept of blockchain was hot, many related top domain names were registered and used as blockchain platforms.
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