Is blockchain transaction modified
the confirmation times of bitcoin are different from that of Ruitai coin, Laite coin and doggy coin.
first, define the
blockchain as an open network ledger. It originated from bitcoin and is the underlying technology of bitcoin. In bitcoin transactions, all the information of transaction records will be packaged into a "block" for storage. With the expansion of information exchange, one block links with another, forming a blockchain
Second, the digital currency represented by bitcoin is a point-to-point e-cash system. Among them, every transaction will broadcast to all participants in the network, and it will be recorded in the account book after repeated confirmation, which is called "blockchain". Each participant will have his own account book. In this way, when false information occurs, it can be broken through mutual verification, so as to ensure network securityin the blockchain, every node is equal, and there is no centralized management organization. This "decentralized" feature makes the blockchain do not need to rely on a third party, its operation does not need any human intervention, and it can independently conct self verification. In addition, the network of blockchain is open to the world, and anyone can query data through the public port, so the whole system is highly transparent
In a word, blockchain is a reliable database and a reliable "account book". In the future, it will be applied in cross-border payment, securities, loans, voting, etc. For example, in cross-border payment, with the security of blockchain, you can remit money to the world anytime and anywhere, which saves a lot of intermediate links and high feesthe centralized trading platform covers the whole trading process including account opening, recharge, automatic transfer and transaction withdrawal. That is to say, when we put our digital assets into the address of the trading platform, the trading platform becomes the trustee of our digital assets, and the control of the actual assets is in the hands of the trading platform
different from the centralized trading platform, the decentralized platform does not need to register an account. It only needs to undertake the responsibilities of asset custody, matching transaction and asset clearing, and does not need to provide non trading function, account system, kcy and legal currency exchange functions like the centralized exchange; On the other hand, in the decentralized trading platform, all operations are realized through smart contracts, and this transaction needs to wait for the confirmation of the blockchain before it is successfully completed
based on the above attributes, the decentralized platform avoids the moral hazard of the trading platform and the centralized attack of hackers to a certain extent. However, in this trading mode, the security of assets depends on the users themselves.
each node on the blockchain can verify the integrity and authenticity of the account book to ensure that all transaction information is not tampered with, true and effective
every node on the blockchain keeps copies of all transaction information. When the number of data and participants on the blockchain is very large, the cost of modifying information will be very high. At least 51% of the computing power of the whole network is needed to modify information, and the modification cost may far exceed the expected revenue
when the information of some nodes is maliciously tampered with, other nodes on the blockchain will find the information that has not formed a "consensus" in a short time and maintain and update it.
Let's suppose villagers Lao Wang and Xiao Li. Lao Wang borrowed some money from Xiao Li, who wrote it in an IOU signed by both parties. A few days later, Lao Wang denied the existence of borrowing money and claimed that Xiao Li forged the paper. Xiao Li can't argue because he finds it difficult to prove that Lao Wang actually owes him money
in this example, Lao Wang and Xiao Li are two nodes
now assuming the same scenario, there are many pairs of people trading with each other in the village. The only evidence for each pair is the IOU. If one party fails, it will be difficult to do so. Seeing this scene, the village head came up with a solution. He suggested using a common notebook for the whole village to record all the transactions. Due to the high prestige of the village head, the villagers unanimously decided to let the village head keep this important transaction book. Each transaction, the villagers go to the village head's home, let the village head witness and record, each transaction is written into a notebook, and then safely saved. That notebook can be called a database
because this notebook is very important, the village head locked it in the safe. However, there are always some problems. Sometimes, the village head will accidentally sprinkle ink on the paper, making some transaction records illegible. This is called a single point of failure. The thief knows that there is an important notebook in the safe of the village head's house. He tries his best to steal it. This is called hacking
until one day, the village head's son owed others a lot of money, so the village head secretly deleted his son's debt entry. In this way, the village head's son "does not owe money."
when the villagers knew this, they began to question the fairness and authority of the village head. So some people put forward a new idea:
abolish the power of the village head, which is called decentralization. Let all villagers keep a notebook, and the transaction records are copied and distributed, which is called distributed database. Therefore, if there are n people in the village, there are n notebooks, that is, n nodes. Every time there is a trade between any two people, all the people in the village get together and record it in their notebooks. And no one can cover the sky. This is called decentralization
they also decided that they would never delete the mentioned transactions from their notebooks, which is irreversible. For example, Lao Wang borrowed a sum of money from Xiao Li before, but in the twinkling of an eye, he wants to return the money. Then the transaction book will not delete the previous borrowing record, but write a new repayment record, so there are two records
next, let's try to break this rule. What if we bribe Lao Wang to change his notebook? It's not feasible, because the next time the villagers meet, they find that Lao Wang's notebook is different from everyone else's, so the villagers notice that Lao Wang may be engaged in an indescribable transaction, and decide to abolish Lao Wang's transaction record and kick Lao Wang out of the organization
What if you try to bribe all the villagers? It's too expensive
the characteristic of this model is that greedy people need to pay a lot to attack the rules. He will find it more profitable to follow the rules
a smart child in the village suggested that each transaction data be called "block" and linked into a "chain" in chronological order, which is called blockchain
in a narrow sense, blockchain is a kind of chained data structure, which is composed of data blocks connected in sequence according to the time sequence, and is a distributed account that can not be tampered with and forged by cryptography. In a broad sense, blockchain technology is a new distributed infrastructure and computing paradigm, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data
blockchain and big blockchain are not the same concept. Big blockchain should be the name of a company. Bitcoin, Ethereum and decent are all successful cases of blockchain technology.
Blockchain is a kind of chain data structure that combines data blocks in order according to the time sequence, and it can't be tampered and forged by cryptography. In a broad sense, blockchain technology is a new distributed infrastructure and computing paradigm, which uses blockchain data structure to verify and store data, uses distributed node consensus algorithm to generate and update data, uses cryptography to ensure the security of data transmission and access, and uses intelligent contract composed of automated script code to program and operate data< br />
1. Blockchain technology can realize the automatic transaction settlement of the exchange, bypass the third party, improve the transaction speed, rece costs, rece operational risks and human errors
2. At present, blockchain technology is mainly used for post transaction clearing services, as well as equity trading management in the OTC market, rather than the mainstream exchange market. The reason is that blockchain technology needs a lot of storage space and a long confirmation time, coupled with the limitation of transaction speed, it is not suitable for centralized floor trading
3. Because of its confidentiality and unchangeable characteristics, blockchain is suitable for securities registration and can rece the registration time
4. Blockchain technology is a double-edged sword for the exchange. On the one hand, it helps the exchange rece the operating costs and risks, and on the other hand, it also reces the income of the exchange in clearing (the decrease of settlement fees and the shortening of settlement cycle will rece the interest income of the custody bank and settlement company). Therefore, for the exchange, it is necessary to develop new data services to make up for the revenue after using the blockchain
of course, blockchain will also have some positive effects on traditional instries. Blockchain has had a positive impact on crowdfunding, banking and tea collection. Puyin group launched the tea based digital currency Puyin.