How many nodes does bitcoin need
The total number of bitcoins is 21 million
in 2009, when bitcoin was born, block reward was 50 bitcoins. Ten minutes after its birth, the first 50 bitcoins were generated, and the total amount of money at this time is 50. Then bitcoin grew at a rate of about 50 every 10 minutes. When the total amount reaches 10.5 million (50% of 21 million), the block reward will be halved to 25
when the total amount reaches 15.75 million (5.25 million new output, i.e. 50% of 1050), the block reward will be further halved to 12.5. The monetary system used to have no more than 10.5 million in four years, after which the total number will be permanently limited to about 21 million
extended data
monetary characteristics
1. Decentralization: bitcoin is the first distributed virtual currency, and the whole network is composed of users without a 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
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
According to 1ml data, the current number of bitcoin lightning network nodes has reached 18061, an increase of 7.30% in the past 30 days; The number of channels was 40065, which increased by 5.9% in the past 30 days; Network capacity reached 1154 BTCs, an increase of 6% in the past 30 days
blockchain technology workstation under "BTC
Lianqiao ecation online" is the only approved "blockchain Technology Specialty" pilot workstation of "smart learning workshop 2020 Xueshuo innovation workstation" launched by the school planning, construction and development center of the Ministry of ecation of China. Based on providing diversified growth paths for students, the professional station promotes the reform of the training mode of the combination of professional degree research, proction, learning and research, and constructs the applied and compound talent training system
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: January 8, 2021. Please refer to the official website of Ping An Bank for the latest business changes
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When bitcoin nodes connect with each other, they will get transactions they don't have from each other. But because bitcoin has accumulated a large number of transactions for a long time, it is very difficult for two nodes to compare which transactions you are missing / which transactions I am missing one by one
to solve this problem, Nakamoto Tsung invented the important technology of block chain. Nodes use blocks to synchronize transactions, which ensures the data consistency of all nodes, and ensures the uniqueness of the blockchain by competing for block packing rights (that is, mining)
① a block and blockchain
a packet formed by a transaction over a period of time is called a block. On average, bitcoin generates a block every 10 minutes, and each block is linked to the previous block to form a blockchain
② the transaction data is synchronized with the block as a unit
the block is numbered from 1, so after node a connects with node B, it is convenient to synchronize the transaction data as long as the block number height of both parties is checked. For example, if node A's own block height is 100 and node B's block height is 110, all it needs to do is request B to synchronize the 10 blocks 101-110<
③ reward for packed blocks
in order to ensure that there are nodes to pack bitcoin transactions, bitcoin rules stipulate that nodes of packed transactions will receive bitcoin as reward
A. part of the package reward comes from the transaction fee paid by the transaction creator (100-1000 transaction fee per KB)
B. the other part comes from the initial distribution of 21 million bitcoins. At the beginning, the reward is 50 bitcoins for each block. After that, the reward will be halved for every 210000 blocks (about four years). Until about 2140, the reward for each block is less than 1, and the total reward for each block is 21 million bitcoins, This is the source of the total amount of 21 million bitcoins (2099999.97690000 to be exact)
after 2140, the package reward will only come from the transaction fee paid by the transaction creator<
④ competition for block packing right
node packing transaction only needs to consume very low-cost network and computing resources. The existence of packing reward (at present, the packing reward for each block is 25 bitcoin, about 40000 yuan), makes a large number of nodes want to pack transactions. In order to ensure the uniqueness of the blockchain, bitcoin rules stipulate that nodes use a method similar to "coin tossing" to compete for the right of transaction packaging. Nodes constantly toss coins. Whoever first throws the results that meet the rules will get the right to pack the transaction in this block, as well as the package reward of this block
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 currency 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
according to the notice on preventing the financing risk of token issuance, there is no approved digital currency trading platform in China. According to China's digital currency regulatory framework, investors have the freedom to participate in digital currency transactions at their own risk
warm tips: the above information is for reference only. Before investing, it is recommended that you first understand the risks existing in the project, and 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: January 14, 2021. Please refer to the official website of Ping An Bank for the latest business changes
[Ping An Bank I know] want to know more? Come and see "Ping An Bank I know" ~
https://b.pingan.com.cn/paim/iknow/index.html
bitcoin is a kind of point-to-point e-cash system, more directly, node to node. Each transaction is broadcast by the originator to the nodes around it, and then broadcast to the nodes around it after receiving it, and finally spread to the whole network
every bitcoin wallet is a node, and the node with a complete blockchain ledger is called the whole node. In October 2017, there were about 9300 nodes in the bitcoin network, which were responsible for broadcasting and verifying bitcoin transfer transactions. After the transfer transaction occurs, all nodes broadcast to the whole network. After the mining node verifies that the transaction is correct, it will be recorded in the blockchain ledger. The United States, Germany and France have the largest number of bitcoin nodes, with China accounting for about 5% of the world's total nodes Data source: bitcodes. 21. CO) running bitcoin node does not provide any reward, and it does not need the whole node to transfer bitcoin, so the total number of bitcoin nodes only accounts for a small part of the node number.
does each node have complete blockchain data? You mean a user node? A user node needs to keep the of the block head of the longest workload proof chain, so it knows the data of all the block heads. It can move forward to know all the data on the block chain, but not all of them are saved. A block header is very small, only 80 bytes, which can be saved completely, because the generation of nodes is very slow. Even with the passage of time, the amount is not too large now.
as we all know, bitcoin is generated by a network node after completing the calculation of specific mathematical problems, and with the passage of time, the generation of bitcoin will be slower and slower. With the discovery of data blocks, unlocking a single block will be more and more complex, but the bitcoin will be less and less. Unless you use circuits or computer systems designed for mining, such as GPU computing, it's hard to quickly mine bitcoin - and these systems, in general, consume a lot of power< A computer used for mining bitcoin is very expensive in electricity and body.
the tracking results of foreign institutions on bitcoin data show that bitcoin miners use 1 million kilowatt hours of electricity every day - yes, 1 million kilowatt hours of electricity, which costs US $150000 in total to mine bitcoin. At the current exchange rate, the daily income of miners is about 470000 US dollars, but the majority of the income is not attributable to ordinary people like you and me. Most of these benefits are taken away by people who have built a special mining system. If ordinary users use ordinary computers to dig bitcoin, the benefits can't catch up with the electricity bill
as an emerging e-currency, bitcoin is not as easy to dig as it used to be, and its market prospect is difficult to determine.