What does V4 mean on bitcoin

5. In order to understand the technical principle of bitcoin, we need to understand two important cryptographic techniques: hash code: it converts a long string into a fixed length string, and its conversion is irreversible, that is, it is impossible to guess the original string from hash code. Sha256 is mainly used in bitcoin protocol
public key system: corresponds to a public key and a private key, keeps the private key in the application and publishes the public key. When Party A transmits information to Party B, it can use Party A's private key to encrypt the information, and Party B can use Party A's public key to decrypt the information, so as to ensure that the third party cannot impersonate Party A to send the information; At the same time, when Party A transmits information to Party B, it is encrypted with Party B's public key and sent to Party B, and then Party B decrypts it with his own private key, so as to ensure that the third party cannot eavesdrop on the communication between the two people. RSA is the most common public key system, but the lliptic curve digital signature algorithm is used in bitcoin protocol. What's the difference between cash and bank account? Bitcoin is an electronic currency in BTC. In this article, it is also used to refer to the whole bitcoin system. Like opening an account in a bank, the corresponding concept in bitcoin is address. Everyone can have one or more bitcoin addresses, which are used to pay and collect money. Each address is a string that starts with 1. For example, I have two bitcoin accounts, and. A bitcoin account is uniquely determined by a pair of public key and private key. To save the account, you only need to save the private key file. Unlike bank accounts, banks keep all transaction records and maintain the book balance of each account, while bitcoin's transaction records are jointly maintained by the whole P2P network through a pre agreed protocol. How much money is in my account address? Although the current account balance can be seen by bitcoin software, unlike banks, there is no place to maintain the book balance of each address. It can only calculate the account balance in real time through all historical transactions. How do I pay? When I pay from address a to address B of the other party, the payment amount is e. at this time, both parties will announce the transaction information to each network node, telling address a to pay to address B, and the payment amount is e. In order to prevent the third party from forging the transaction information, the transaction information will be encrypted with the private key of address A. at this time, the network node receiving the transaction information can use the public key of address a to verify that the transaction information is indeed sent by address a. Of course, trading software will help us do these things, we just need to input the relevant parameters in the software. What will the network node do after receiving the transaction information? This is the most important part of the bitcoin system, which needs to be elaborated. For the sake of simplicity, only bitcoin protocol has been implemented. In the current version, each network node will save all transaction information synchronously. There are two kinds of transaction information in history, one is & quot; Verified & quot; The transaction information, that is, the verified transaction information, is stored in a series of "blocks". Each & quot; block" Is the previous & quot; bock" The ID of each block is the hash code of the hash code of the block and the new transaction information (see an actual block). The other category refers to those who also & quot; Unverified & quot; The transaction information just paid above belongs to this category. When a network node receives new unverified transaction information (possibly more than one), it can calculate the book balance of each address at that time because the node keeps all the transaction information in history, so it can calculate whether the transaction information is valid, that is, whether there is enough balance in the payment account. After eliminating the invalid transaction information, it first takes out the last & quot; block" Then, the unverified transaction information is combined with the ID, and a verification code is added to form a new "block". It needs a lot of calculation to build a new block, because it needs to calculate the verification code, so that the above combination becomes a block, that is, the first several bits of the hash code of the block are 1. At present, the first 13 bits need to be 1 (generally, the specific method is uncertain), which means that if the block is generated by enumeration method, the average number of enumerations is 16 ^ 13. Using CPU resources to generate a block is called "gold mining", because the proction of the block will get a certain reward, and the reward information has been included in the block. When a network node generates a new block, it will broadcast to other network nodes. However, this network block may not be accepted by the network, because it is possible that other network nodes have proced the block earlier. Only the earliest block or the block with the largest number of subsequent blocks is valid, and the remaining blocks are no longer used as the initial blocks of the next block. How does the other party confirm that the payment is successful? When the payment information is distributed to the network node, the network node begins to calculate whether the transaction is valid (that is, whether the account balance is enough to pay), and attempts to generate blocks containing the transaction information. When six blocks (one direct block and five subsequent blocks) contain the transaction information, the transaction information is considered "verified", so that the transaction is formally confirmed, and the other party can confirm the successful payment. A possible problem is that I will pay the balance of address a to address B, and at the same time pay to address C. If I only verify that the single comparison transaction is valid. At this point, my way of cheating is to generate six blocks including B to B and six blocks including C to C before the truth is revealed. Because I need a very long CPU time to generate a block, compared with the whole network, the probability of my cheating success is very small. What is the motivation of network nodes to proce blocks? As can be seen from the above description, in order to make the transaction information effective, the network node needs to generate 1 and 5 subsequent blocks to contain the transaction information, and such block generation is very CPU intensive. How to let other network nodes help to proce blocks as soon as possible? The answer is very simple. The agreement stipulates that BTC will be rewarded for the address where the block is proced, as well as the Commission promised by both parties. At present, the reward for procing a block is 50btc, which will be halved every four years in the future. For example, the reward will be 25btc from 2013 to 2016. Is the transaction anonymous? Yes, and No. All bitcoin transactions are visible. We can check all transaction records of each account, such as mine. But what's different from the banking monetary system is that everyone's account itself is anonymous, and everyone can open many accounts. In general, anonymity is not as good as it claims. But bitcoin has another advantage in doing black market trading: it can't be frozen. Even if the police trace a bitcoin address, there is nothing they can do unless they trace the computer used by the exchange based on the Internet address. How to ensure that bitcoin does not depreciate? Generally speaking, in the case of equivalent trading activities, the value of money is inversely proportional to the amount of money issued. Unlike the traditional money market, the central bank can determine the amount of money issued. Bitcoin does not have a central issuing institution. Only by procing blocks can we get a certain amount of BTC currency. Therefore, bitcoin's new amount of money depends on: 1. The speed of procing blocks: bitcoin's agreement stipulates that the difficulty of procing blocks is fixed at an average of 2016 every two weeks, about 10 minutes. Moore's law of doubling CPU speed every 18 months will not speed up the proction of block. 2. The number of rewards for block proction: at present, 50 BTC is awarded for each block proced, which is halved every four years. In 2013, 25 BTC is awarded, and in 2017, 12.5 BTC is awarded. Considering the above two factors, bitcoin's currency issuing speed is not controlled by any single node in the network. Its protocol makes the currency stock known in advance, and the maximum stock is only 21 million BTC

6.

Bitcoin is a kind of virtual encrypted digital currency in the form of P2P. Different from all currencies, bitcoin does not rely on specific currency institutions. It is generated by a large number of calculations based on specific algorithms. Bitcoin economy uses the distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, And the use of cryptography design to ensure the security of all aspects of money circulation. However, on September 4, 2017, the central bank and other seven ministries and commissions announced that virtual currency trading is prohibited in China, and bitcoin is prohibited from circulating in China

according to the first article of the notice on preventing the financing risks of token issuance, we should accurately understand the essential attributes of token issuance financing activities. Token issuance financing refers to the illegal sale and circulation of tokens by the financing subject to raise the so-called virtual currency such as bitcoin and ether coin from investors. In essence, it is an unauthorized illegal public financing behavior, which is suspected of illegal sale of token bills, illegal issuance of securities, illegal fund-raising, financial fraud, pyramid schemes and other illegal criminal activities

Relevant departments will closely monitor relevant developments, strengthen cooperation with judicial departments and local governments, strictly enforce the law in accordance with the current working mechanism, and resolutely deal with market chaos. If suspected crimes are found, they will be transferred to judicial organs. The token or "virtual currency" used in token issuance financing is not issued by the monetary authority, does not have such monetary attributes as legal compensation and compulsion, does not have the same legal status as currency, and cannot and should not be used as currency in the market

extended information:

Article 3 of the announcement on preventing the financing risk of token issuance strengthens the management of token financing trading platform. From the date of this announcement, any so-called token financing trading platform shall not engage in the exchange business between legal tender and token and "virtual currency", nor buy or sell token or "virtual currency" as a central counterpart, nor provide pricing, information intermediary and other services for token or "virtual currency"

for the token financing trading platform with illegal problems, the financial management department will request the competent department of telecommunications to close its website platform and mobile app according to law, request the network information department to remove the mobile app from the app store, and request the instrial and commercial administration department to revoke its business license according to law

Article 4 financial institutions and non bank payment institutions shall not carry out business related to token issuance financing transactions. All financial institutions and non bank payment institutions shall not directly or indirectly provide procts or services such as account opening, registration, trading, clearing and settlement for token issuance and financing and "virtual currency", nor undertake insurance business related to token and "virtual currency" or include token and "virtual currency" into the scope of insurance liability. Financial institutions and non bank payment institutions shall report to the relevant departments in a timely manner if they find clues of violation of laws and regulations in token issuance financing transactions

7. Bitcoin is BTC and eth is Ethereum
the concept of bitcoin was first proposed by Nakamoto on November 1, 2008, and was officially born on January 3, 2009 [1]. According to the idea of Nakamoto, the open source software is designed and released, and the P2P network on it is constructed. Bitcoin is a virtual encrypted digital currency in the form of P2P. Point to point transmission means a decentralized payment system
Ethereum is an open source public blockchain platform with smart contract function, which provides decentralized Ethereum virtual machine to process point-to-point contract through its special cryptocurrency ether (ETH)

warm tips:
1. The above information is for reference only, without any suggestions
2. According to the notice on preventing the financing risk of token issuance, there is no approved digital currency trading platform in China. According to the regulation of digital currency in China, investors have the freedom to participate in digital currency transactions at their own risk
response time: February 1, 2021. Please refer to the official website of Ping An Bank for the latest business changes
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8. According to the legendary algorithm, bitcoin has an upper limit of 21 million. But you know the algorithm. Although it's very difficult to make adjustments in theory, if you (the legendary top trading institutions with trillions of wealth) really want unlimited, it's a matter of minutes

theoretically, 2100 trillion, or 250.899. In terms of selecting this value, this number is far less than 264-1, which is the largest integer that can be stored in the form of standard integer in a computer. If it exceeds that value, the bitcoin value will return to zero like a odometer

but this is only theoretical, just theoretical. Just like the previous IP address regulations, no one expected that V4 would be used up so quickly. Now it is necessary to use V6. This so-called "maximum integer that can be stored in the form of standard integer" may be broken by the technology upgrade one day a year later, followed by the collapse of the whole bitcoin computing.

9. In 2013, their website server was basically paralyzed after being attacked by hackers. Many investors have suffered heavy losses and are now unstable.