Blockchain is essentially a distributed shared database.
Blockchain is a chain data structure that combines data blocks in a specific order in chronological order. It stores records of all transactions since the birth of the system. The data on the blockchain is jointly maintained and stored by nodes throughout the network, and cryptography ensures that the block data cannot be tampered with or forged.
Blockchain allows any number of nodes participating in the system to generate associated data blocks (i.e. blocks, blocks) through cryptographic methods. Each data block contains data on all information exchanges in the system within a certain period of time, and Blocks of data are combined into a chained data structure in chronological order.
The principle of blockchain recording requires all nodes participating in the recording to jointly verify the correctness of the transaction record. Since all nodes are recording every transaction in the entire network, once the information recorded by a node does not match that of other nodes, other nodes will not recognize the record, and the record will not be written into the block.
It is almost impossible to change a certain block and the transaction information within the block. If this block is changed, every subsequent block will be changed. Therefore, anyone trying to tamper with the data must simultaneously invade at least 51% of the nodes participating in the global record and tamper with the data. Technically, this is almost impossible.
Each transaction requires a valid signature to be stored in a block. Only valid digital keys can generate valid signatures. Keys come in pairs and consist of a private key and a public key. Among them, the public key is public, and the private key is only visible and used by the owner, and is used for transaction signatures to prove digital identity.
The distributed structure of the blockchain allows data not to be recorded and stored on a centralized computer or host, but rather allows every node participating in data transactions to record and store all data information. To this end, the blockchain system uses an open source, decentralized protocol to ensure complete recording and storage of data.
The blockchain has built a complete set of protocol mechanisms, allowing each node in the entire network to participate in recording data while also participating in verifying the correctness of the recording results of other nodes. Only when most nodes (or even all nodes) in the entire network confirm the correctness of the record will the data be written into the block. In the distributed structure network system of the blockchain, the network nodes participating in the recording will update and store all data in the entire network system in real time. Therefore, even if some nodes are attacked or destroyed, the data update and storage of this system will not be affected.
