2 bitcoin is

2. 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

3.

Bitcoin is a kind of electronic currency / network virtual currency

bitcoin: also known as "bitcoin", is a kind of network virtual currency. Internet users can use bitcoin to buy some virtual goods, such as clothes, hats, equipment, etc. in online games. Internet users can also use bitcoin to buy real goods

on February 26, 2014, Joe Manchin, a Democratic senator from West Virginia, issued an open letter to a number of regulatory authorities of the US federal government, hoping that the relevant authorities would pay attention to the status quo of bitcoin's encouraging illegal activities and disrupting the financial order, and demanded that actions be taken as soon as possible to completely ban the electronic currency

from 12:00 noon on January 24, 2017, China's three major bitcoin platforms officially began to collect transaction fees

extended data:

currency features:

1, decentralization: bitcoin is the first distributed virtual currency, the whole network is composed of users, and there is no central bank. Decentralization is the guarantee of bitcoin's security and freedom

2, global circulation: bitcoin can be managed on any computer connected to the Internet. No matter where you are, anyone can dig, buy, sell or collect bitcoin

3, exclusive ownership: private key is needed to control bitcoin, which can be stored in any storage medium in isolation. No one can get it except the user himself

4, low transaction cost: bitcoin can be remitted free of charge, but a transaction fee of about 1 bitfen will be charged for each transaction to ensure faster transaction execution

5, no hidden cost: as a means of payment from a to B, bitcoin has no cumbersome limit of quota and proceres. If you know the other party's bitcoin address, you can pay

6, cross platform Mining: users can explore the computing power of different hardware on many platforms

advantages of bitcoin:

1, it is completely decentralized, without issuing institutions, it is impossible to manipulate the number of issues. Its distribution and circulation are realized through open-source P2P algorithm

2, anonymity, tax exemption and supervision free

3, robustness. Bitcoin is completely dependent on P2P network and has no distribution center, so it cannot be shut down externally. Bitcoin price may fluctuate and collapse, and many governments may declare it illegal, but bitcoin and its huge P2P network will not disappear

4, borderless and cross-border. Cross border remittance will go through layers of exchange control agencies, and the transaction records will be recorded by many parties. But if you trade with bitcoin, enter the digital address directly, click the mouse and wait for the P2P network to confirm the transaction, a lot of money will pass. It does not go through any regulatory agencies and will not leave any cross-border transaction records

5, Shanzhai people are difficult to survive. Because bitcoin algorithm is completely open source, anyone can download the source code, modify some parameters, recompile, and create a new P2P currency

but these counterfeit currencies are very fragile and vulnerable to 51% attacks. Any indivial or organization, as long as it controls 51% of the computing power of a P2P currency network, can manipulate transactions and currency value at will, which will be a devastating blow to P2P currency

many counterfeit coins die in this link. The bitcoin network is robust enough. If you want to control 51% of the computing power of the bitcoin network, the number of CPUs / GPUs required will be astronomical

the weakness of bitcoin

1, the fragility of trading platform. The bitcoin network is robust, but the bitcoin trading platform is fragile. Trading platform is usually a website, which will be attacked by hackers or shut down by competent authorities

2, the transaction confirmation time is long. When bitcoin wallet is first installed, it will consume a lot of time to download historical transaction data blocks. While bitcoin transaction, in order to confirm the accuracy of data, it will take some time to interact with P2P network, and the transaction will be completed only after the whole network is confirmed

3, the price fluctuates greatly. Due to the intervention of a large number of speculators, the price of bitcoin for cash fluctuates like a roller coaster. Making bitcoin more suitable for speculation rather than anonymous trading

4, the public did not understand the principle, and the traditional financial practitioners resisted. Active netizens understand the principle of P2P network and know that bitcoin has no legal person to manipulate and control

but the public doesn't understand, and many people can't even distinguish between bitcoin and q-coin“ "No issuer" is the advantage of bitcoin, but in the view of traditional financial practitioners, "no issuer" currency is worthless

5. Bitcoin is a kind of cryptocurrency based on decentralization, using peer-to-peer network and consensus initiative, open source, and blockchain as the underlying technology. The concept of bitcoin was first proposed by Nakamoto on November 1, 2008, and was officially born on January 3, 2009. Unlike all currencies, bitcoin does not rely on a specific currency institution to issue. It is generated by a large number of calculations based on a specific algorithm. Bitcoin economy uses a distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, and uses cryptography design to ensure the security of all aspects of money circulation. The decentralized nature and algorithm of P2P can ensure that it is impossible to artificially manipulate the value of bitcoin through mass proction. The design based on cryptography can make bitcoin only be transferred or paid by the real owner. This also ensures the anonymity of money ownership and circulation transactions. The biggest difference between bitcoin and other virtual currencies is that the total amount of bitcoin is very limited and it has a strong scarcity

warm tips:
1. The above explanations are for reference only, without any suggestions
2. Before investing, it is recommended that you first understand the risks existing in the project, and clearly understand the investors, investment institutions, chain activity and other information of the project, rather than blindly investing or mistakenly entering the capital market. Investment is risky, so we should be cautious when entering the market
response time: December 17, 2020. Please refer to the official website of Ping An Bank for the latest business changes
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6.

Bitcoin (abbreviated as BTC) is a point-to-point, decentralized digital asset proposed by Nakamoto (alias); In 2009, Nakamoto Cong packaged the first block and won 50 bitcoin mining awards, which are halved every four years. According to this calculation, bitcoin is expected to be issued in 2140, with a total of 21 million

do you understand what bitcoin is now? If you don't understand, just continue to look down ~ "blockchain 100 questions" makes you a blockchain brick~

7. Bitcoin (abbreviated as BTC) is a point-to-point, decentralized digital asset proposed by Nakamoto (alias); In 2009, Nakamoto Cong packaged the first block and won 50 bitcoin mining awards, which are halved every four years. According to this calculation, bitcoin is expected to be issued in 2140, with a total of 21 million. With