To understand this, we need to introduce a concept: Hash algorithm. There are many kinds of Hash algorithms, and the basic function is to convert a data file of any length into a unique corresponding fixed-length string.
You can understand it as generating a string of fixed-length garbled tags for any file.
This algorithm is irreversible, that is, if you get this tag, you cannot derive the original data file backward.
If there is a little change in the data file, such as adding a punctuation mark, after re-hashing, the new label will be very different from the original label.
It is not possible to guess what has changed in the data file from the difference between the old and new labels. Therefore, through the label, you can easily verify that a certain file exists at a certain moment, or verify whether two files are the same.
It is this irreversibility that determines the immutability of the blockchain. In each block, in addition to the transfer transaction data within ten minutes, there is also a block header.
The block header contains the hash value of the previous block data. These hashes are nested layer by layer, with a fixed length, and finally all blocks are connected in series to form a blockchain. The blockchain contains all transactions and all new currency issuances that have occurred since the birth of the chain.
If I were a bad person, I would tamper with a transaction. The transaction includes the sender and receiver, and the number of transfers. The sender’s Bitcoin can be traced all the way to the earliest block where the coin was newly issued.
The legitimacy of the sender's possession of these bitcoins is guaranteed by the original issuance block record of the coin and all historical transaction records related to the coin.
Therefore, to tamper with a transaction means that all the hash and related transaction records after it must be tampered with again. This requires extremely high computing power and difficulty, and the probability of success is zero.
So there are so-called six confirmation questions. After a transaction is packaged into blocks, and then 6 blocks are connected in series, this transaction is basically unchangeable. It can be compared to queuing.
If everyone agrees that the longest team is a legitimate team, then after you are ranked, you should be most concerned about how many people are behind you. Because, the more people behind you, the stronger your legitimate interests.
In the news, pictures of chain links are often used to show the blockchain. Strictly speaking, this is not accurate. Chains or necklaces are linear in structure.
Remove one of the links and the entire chain will not lose much. The structure of the blockchain is not like this, because there is a hash algorithm, the bite is stronger, and it cannot be changed a little without hurting others. This is the source of the immutable nature of the blockchain.
Unalterable technology for data storage and transmission
Systems used in the insurance and medical industries for data storage and transmission generally prioritize their unalterable performance. At present, these industries are actively exploring the potential of blockchain technology and believe that this technology has incomparable potential in terms of immutability.
Blockchain startups like MyBit have been looking for ways to use blockchain technology for data storage and transmission. Ian Worrall, co-founder and managing director of MyBit said:
;MyBit uses decentralized distributed ledger technology to realize the safe management of asset ownership, thereby completely changing the asset management industry. It effectively eliminates the risk of single point of failure, the risk of relying on third-party escrow agents, and most of the friction in traditional systems. ;