Blockchain is a kind of distributed ledger, which combines data blocks into a chain data structure in chronological order, and ensures that it cannot be tampered with or forged through cryptographic technology. The ledger guarantee mechanism mainly includes the following aspects:

1, * * * knowledge confirmation: The * * knowledge mechanism in blockchain technology refers to the process in which all nodes participate in decision-making and reach an agreement in a decentralized network. In this process, all nodes can see all behaviors in the network and maintain local books of these observed behaviors on their respective nodes. The whole system is transparent to every node.

2. Multi-party storage: The essence of blockchain is the distributed ledger technology shared by many parties. The data or information stored in it has the characteristics of "unforgeable, tamper-proof, trace-keeping, traceability, openness and transparency, and collective maintenance".

3. Safety and credibility: Blockchain technology realizes the imperturbability of transaction data and historical records through mathematical methods, and realizes the * * * unanimous confirmation and account book record of transactions by all participants through * * * identification algorithm and smart contract. The decentralized, distributed storage, encryption algorithm and * * * identification mechanism of blockchain make the blockchain network highly secure and tamper-proof.

4. Non-tampering: An important feature of blockchain is "non-tampering". Once the transaction is verified in the whole network and added to the blockchain, it is difficult to modify or delete it.