Blockchain is a chain composed of one block after another. A certain amount of information is stored in each block, and they are connected into a chain according to their own time sequence. The chain is stored in all servers. As long as one server in the whole system can work, the whole blockchain is safe. These servers are called nodes in the blockchain system, and they provide storage space and computing power support for the whole blockchain system. If you want to modify the information in the blockchain, you must obtain the consent of more than half of the nodes to modify the information in all nodes, and these nodes are usually in the hands of different subjects, so it is extremely difficult to tamper with the information in the blockchain. Compared with traditional networks, blockchain has two core characteristics: one is that data is difficult to tamper with, and the other is decentralization. Based on these two characteristics, the information recorded by blockchain is more authentic and reliable, which is helpful to solve the problem of mutual distrust.
Blockchain originated from bitcoin. On June 1 65438+1October1day, 2008, a person who claimed to be Satoshi Nakamoto published the article "Bitcoin: A Peer-to-Peer Electronic Cash System", expounding the architecture concept of an electronic cash system based on P2P network technology, encryption technology, timestamp technology and blockchain technology, which marked the birth of Bitcoin. Two months later, the theory entered into practice, and on June 38, 2009+10/October 3, the first Genesis block numbered 0 was born. A few days later, on June 9, 2009, the block with serial number 1 appeared and became a chain with the Chuangshi block with serial number 0, marking the birth of the blockchain.
Narrow-sense blockchain is a chain data structure, which combines data blocks in an orderly way according to time sequence, and cryptographically guarantees that it is an unbreakable and unforgeable distributed account book. Generalized blockchain technology is a brand-new distributed infrastructure and computing paradigm. 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.