Blockchain technology has the characteristics of decentralization, information cannot be tampered with, information is transparent and can be jointly maintained. The basic concepts and principles of blockchain technology will be explained below.
1. Blockchain concept
Blockchain can use cryptography to concatenate and protect concatenated transaction records (also known as blocks) of content. In the blockchain, the content of the block is difficult to tamper with. Each block contains the encrypted hash of the previous block, the corresponding timestamp, and transaction data (usually represented by a hash value calculated by a Hash tree). Distributed ledgers connected by blockchain can effectively record transactions between both parties and can be permanently verified.
2. Blockchain principle
Blockchain technology can be considered to solve the “Byzantine Generals Problem” in the Internet era, that is, how to achieve consensus among the various nodes in the network when both the central node and the information transmission channel in the network lack credibility.
Blockchain technology is decentralized and each node does not need to be trusted in advance. Through encryption algorithms, consensus mechanisms and specific data storage methods, it builds a collectively maintained and reliable data model to realize the transfer of digital assets between network nodes. transfer.
First, the data is divided into blocks in chronological order. Each block stores all value exchange information within a period of time. All nodes store the data during this period and save it permanently. Each node competes for leadership through specific calculations. The information of the next time period is packaged and distributed, and certain specific information is added to the end of the previous block to form a blockchain structure.
The characteristic of this blockchain structure is that it can ensure the integrity of the data, because each block will store all value exchange information before it is created; it can also ensure the rigor of the data, because once a new block is added to the chain , the previous block can no longer be modified.
Blockchain implements a comprehensive distributed model from recording to transmission to storage. Data transmission, data verification, and data storage are all decentralized, and all participants jointly build a database.
Blockchain uses an asymmetric encryption algorithm to improve the trustworthiness of data. Asymmetric encryption means that encryption and decryption use different passwords, that is, public keys and private keys. The password used to encrypt data is called the public key, which is known to everyone and can be used to encrypt information; the password used to decrypt data is called the private key, which is known only to the recipient of the information and used to decrypt it. password. Information encrypted by the public key can only be decrypted using the corresponding private key.
In actual situations, assuming A sends a message to B, A and B each produce a pair of public keys and private keys for encryption and decryption. A and B respectively keep their own private keys and inform the other party of the public key. If A sends a message to B, To send information, A uses B’s public key to encrypt and send the encrypted information to B. After receiving the message, B uses his own private key to decrypt it, and no other participant in the network can decrypt it. This algorithm-strength encryption method ensures the credibility of blockchain information.
Blockchain uses mathematical methods to solve trust problems and uses algorithms to replace centralized third-party institutions to create credit for people and help people reach consensus.
Blockchain uses scripts to allow the system to directly define the conditions required to complete value exchange activities. With scripts, blockchain technology has the opportunity to continuously grow the system to handle some emerging transaction models and ensure its timeliness and practicality. sex.
The script contains a large number of instructions, and each value exchange will record the instructions, such as how the party receiving the value receives it, and what additional conditions need to be met to spend the retained value it has received. The programmability of the script makes it possible to flexibly change the additional conditions for spending the retained value, such as increasing the number of public keys required. It can also specify the conditions for re-transfer of value when value is sent.
