Ⅰ What are the blocks in the blockchain connected by?
Introduced by experts, the blockchain can be generally understood as a distributed public ledger, which is composed of various blocks a chain. In the traditional accounting system, the accounting right is in the hands of the central server.
On the “ledger” of the blockchain, each point on the chain can record information on it, forming a point-to-point accounting system. Therefore, blockchain technology is considered a decentralized technology.
For example, in a village of 100 people, Zhang San bought a cow from Li Si and paid him 10,000 yuan. In the past, he had to rely on the middleman Zhao Liu to transfer his 10,000 yuan to Li Si.
With the blockchain system, Zhang San can directly record his 10,000 yuan to Li Si’s ledger, and the transaction information will be transmitted to the whole village, that is, the entire blockchain system. Make the information visible to 98 other people. The entire transaction process is recorded by the system, which has the advantage of traceability and prevents problems such as loss of Zhao Liu’s account book or Li Si’s refusal to acknowledge the account.
(1) What is blockchain connected? Extended reading
In 2008, Satoshi Nakamoto first proposed the concept of blockchain. In the years that followed, the blockchain became a core component of the electronic currency bitcoin: as a public ledger of all transactions. By utilizing a peer-to-peer network and distributed timestamp servers, blockchain databases are capable of autonomous management.
The blockchain invented for Bitcoin made it the first digital currency to solve the problem of double spending. Bitcoin’s design has been an inspiration for other applications.
II How to connect blocks to form a blockchain
How to ensure that the blockchain is connected in sequence?
A blockchain is formed by connecting a series of blocks generated using a cryptographic algorithm. Each block is filled with transaction records, and the blocks are connected in sequence to form a chain-like structure, which is the blockchain large ledger.
Taking Bitcoin as an example, when miners generate a new block, they need to calculate the new hash value and random number based on the hash value of the previous block, the new transaction block and the random number. That is to say, each block is generated based on the data of the previous block, and this mechanism ensures the uniqueness of the blockchain data.
Because the slight change in the transaction record will completely change the result of the hash value, miners cannot cheat when competing for computing power. The data starts to calculate the random numbers that meet the conditions, which ensures the fairness of mining.
Ⅲ What is blockchain technology? What exactly is blockchain and what is blockchain?
In a narrow sense, blockchain is an A chained data structure composed of sequential connections, and a cryptographically guaranteed untamperable and unforgeable distributed ledger.
In a broad sense, blockchain technology is the use of block chain data structures to verify and store data, the use of distributed node consensus algorithms to generate and update data, and the use of cryptography to ensure data transmission and access. A new distributed infrastructure and computing method that uses smart contracts composed of automated script code to program and manipulate data.
Generally speaking, blockchain system consists of data layer, network layer, consensus layer, incentive layer, contract layer and application layer. layer composition. Among them, the data layer encapsulates the underlying data blocks and related basic data and basic algorithms such as data encryption and timestamp; the network layer includes distributed networking mechanisms, data dissemination 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, etc. 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 the blockchain. In this model, the timestamp-based chain block structure, the consensus mechanism of distributed nodes, the economic incentives based on consensus computing power, and flexible and programmable smart contracts are the most representative innovations of blockchain technology.
[Blockchain core technology]
Blockchain mainly solves the problem of trust and security of transactions, so it proposes Four technological innovations have been made:
1. Distributed ledger, that is, transaction accounting is completed by multiple nodes distributed in different places, and each node records a complete account, so they are all Can participate in monitoring the legality of transactions, and can also testify jointly for it.
The uniqueness of the distributed storage of the blockchain is mainly reflected in two aspects: First, each node of the blockchain stores complete data according to the blockchain structure.Data is divided into multiple copies according to certain rules for storage. Second, the storage of each node in the blockchain is independent and has the same status, relying on the consensus mechanism to ensure the consistency of storage, while traditional distributed storage generally synchronizes data to other backup nodes through the central node.
No node can record the ledger data alone, thus avoiding the possibility of a single bookkeeper being controlled or bribed to keep false accounts. Also because there are enough accounting nodes, in theory, unless all nodes are destroyed, the account will not be lost, thus ensuring the security of the account data.
2. Asymmetric encryption and authorization technology, the transaction information stored on 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 data security and personal privacy.
3. The consensus mechanism is how to reach a consensus among all accounting nodes to determine the validity of a record. This is both a means of identification and a means of preventing tampering. The 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 “minority obeys majority” and “everyone is equal”, in which “minority obeys majority” does not completely refer to the number of nodes, but also the computing power and the number of shares. Or other feature quantities that can be compared by computers. “Everyone is equal” means that when a node meets the conditions, all nodes have the right to give priority to the consensus result, which may become the final consensus result after being directly recognized by other nodes.
4. Smart contracts, smart contracts are based on these credible data that cannot be tampered with, and can automatically execute some pre-defined rules and terms. Taking insurance as an example, if everyone’s information (including medical information and risk occurrence information) is true and credible, then it is easy to automate claims settlement in some standardized insurance products.
In the day-to-day business of insurance companies, although transactions are not as frequent as in the banking and securities industries, the reliance on trusted data continues unabated. Therefore, the author believes that the use of blockchain technology, from the perspective of data management, can effectively help insurance companies improve their risk management capabilities. Specifically, it is mainly divided into the risk management of policyholders and the risk supervision of insurance companies.