Blockchain is a combination of “block” and “chain”, which is essentially a distributed ledger.
So, how is this account book kept and how does it work?
Let us illustrate with an analogy.
In the beginning, one person stood out from a group of people and took a blank piece of paper to keep accounts. The system rewarded this person with a certain amount of rewards (such as 50 bitcoins). After finishing the account, generate an anti-counterfeiting code through the encryption algorithm on this page of the bill, and copy the bill to all other people at the same time. Next, everyone calculates a difficult problem, and the person who calculates it first can keep the account and enjoy the rewards given by the system to the bookkeeper.
When recording the second page of the bill, you need to write the anti-counterfeiting code of the first page of the bill at the beginning, and then record the account. After recording, an anti-counterfeiting code for the second page of the bill is also generated through an encryption algorithm, and then the bill is copied to all others. people. Then, everyone competed for the right to book the third page of bills by calculating the next problem. This page of bills will also be marked with the anti-counterfeiting code of the previous page at the beginning. After recording, an anti-counterfeiting code will be generated and the bill will be synchronized to others, and so on. This page-by-page bill is sequentially passed through the binding thread to become a thicker and thicker ledger, and each participant has a copy.
In the above analogy, a page-by-page bill is called a “block”, and the binding thread is a “chain”. By binding this page-by-page bill into a general ledger in sequence, a “block chain” is formed. , its essence is still a ledger. It’s just that the ledger is owned by the owner, there is no central person or organization, everyone is equal, and everyone can compete for the right to bookkeeping through calculation problems, and the entire ledger is jointly maintained by all participants.
Since there is no central person or organization, how can this jointly maintained ledger prevent malicious people from making fake accounts or tampering with ledger records?
Assume that Zhang San grabs the right to keep the bill on page 100. His friend Li Si originally only had 3,000 yuan in the account, but Zhang San secretly changed it to 30,000 yuan for him. At this time, other people will immediately find out that there is a problem with this account, because the account holder owns a copy, and the ins and outs of Li Si’s assets are recorded in the previous account book. Therefore, other people will refuse to add the 100th page of the bill with errors to the general ledger, and will choose another honest person to record the 100th page of the bill through a calculation problem.
Therefore, we can see that blockchain technology has these characteristics: open and transparent (the account holder owns one, everyone can check it), decentralization (there is no central person or organization), and cannot be tampered with (because any tampering, fraud account will be discovered).
In daily life, many people are accustomed to using WeChat and Alipay to pay when they consume, and WeChat and Alipay act as bookkeepers. We need to trust this bookkeeper not to make mistakes or false accounts. The blockchain is different. Hackers may attack and modify the ledger in a computer, but to actually modify the blockchain data, they need to attack more than half of the ledgers in the computer, which is very difficult, especially for Bitcoin. In the blockchain, there are tens of thousands of nodes for accounting, and the account holder owns one, and they are scattered all over the world.
Therefore, blockchain technology also has great advantages in terms of security. Open and transparent, decentralized, immutable… Because of these advantages, the famous British financial magazine praised the blockchain as a “trust machine”.
