Number of BTC addresses
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
You can download a bitcoin wallet or register on a trading platform. Everyone's bitcoin address is unique. If you have an address, you can make a bitcoin transfer. Download bitcoin client or bitcoin wallet, you can also register your own bitcoin address. A bitcoin address is a string of 26 to 34 bits of letters and numbers, which looks a bit like garbled code
the bitcoin address is an indivial's bitcoin account, which is equivalent to your bank card number. Anyone can transfer bitcoin to you through your bitcoin address. The red box is the bitcoin address. Log in to my bitcoin bag and you can see the money
extended materials:
the concept of bitcoin was first proposed by Nakamoto in 2009. According to Nakamoto's idea, the open source software was designed and released, and the P2P network on it was constructed. Bitcoin is a kind of P2P digital currency. Point to point transmission means a decentralized payment system
unlike most 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 uses the design of cryptography 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. 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 21 million
bitcoin can be cashed and converted into the currency of most countries. Users can use bitcoin to buy some virtual items, such as clothes, hats and equipment in online games. As long as someone accepts it, they can also use bitcoin to buy real-life items
reference: network bitcoin
the assumption is that six data blocks can be generated every hour in the world, and 210000 data blocks can be generated every four years; Then it makes a decreasing payment for the return of data blocks, 50 bitcoin for each data block in the first four years, 25 bitcoin for each data block in the second four years, 12.5 bitcoin for each data block in the third four years, and so on... Finally, the total number of bitcoins is -
210000 x (50 + 25 + 12.5 + 6.25 + 3.125 +...) = 21 million
the cumulative sum in brackets is close to 100 and will never exceed 100, so the total number of bitcoins is 21 million
currently in the second four-year period, each calculated data block contains 25 bitcoins
2. There is no loss of wealth. Many people at home and abroad are digging for bitcoin, and they are also speculating in bitcoin. Computer and Internet speed can only determine the speed of bitcoin digging, but not the value of bitcoin. Even if you say that we dig abroad, we fry. Now we buy a bitcoin for $300, and there will be no bitcoin to dig in the future. Maybe a bitcoin will sell for $3000, and then we sell it again, won't we make a profit? Where is the loss of wealth? Of course, maybe a bitcoin will be worth $3 at that time. Who can say that it is not born by the central banks
3. In addition to bitcoin, there are several similar virtual currencies such as lightcoin. However, they all adopt similar design principles. Therefore, in the future, there will inevitably be a problem that the currency will eventually be widely recognized, and other currencies that are not recognized will be eliminated. Otherwise, a new virtual currency can pop up at any time. It's not the same as printing money, which completely goes against their original design intention.
The concept of 21 million
bitcoin was first proposed by Nakamoto in 2009. According to Nakamoto's idea, open source software was designed and released, and P2P network was built on it. Bitcoin is a kind of P2P digital currency. Point to point transmission means a decentralized payment system
bitcoin is not issued in unlimited quantity, which is different from most currencies. Bitcoin does not rely on a specific currency issuer. But according to the specific algorithm, through a large number of calculations. Its circulation is controlled by software algorithms. The total number is 21 million
extended materials:
generation principle
starting from the essence of bitcoin, the essence of bitcoin is actually the special solution generated by a bunch of complex algorithms. A special solution is one of the infinite (in fact, bitcoin is finite) solutions that can be obtained from the equations. Every particular solution can solve the equation and is unique[ 10] In the metaphor of RMB, bitcoin is the serial number of RMB. If you know the serial number of a note, you have the note. The process of mining is to constantly seek the special solution of this equation system through a huge amount of calculation. This equation system is designed to have only 21 million special solutions, so the upper limit of bitcoin is 21 million
to mine bitcoin, you can download the special bitcoin computing tools, register various cooperation websites, fill the registered user name and password into the computing program, and then click the operation to officially start. After completing the installation of bitcoin client, you can directly obtain a bitcoin address. When others pay, you only need to paste the address to others, and you can pay through the same client. After installing the bitcoin client, it will distribute a private key and a public key. You need to back up your wallet data containing your private key to ensure that your property is not lost. Unfortunately, if the hard disk is completely formatted, personal bitcoin will be completely lost
Let's start with a simple conclusion: a year ago, the data showed that there were about 500000 BTC
two American brothers, Cameron winkleworth and Taylor winkleworth, claiming that they owned 1% of bitcoin [1] 1% of the world's bitcoin? At present, the total amount of bitcoin in the world is about 12 million, that is to say, the two brothers hold about 120000 bitcoins< maybe you don't think it's worth much, but note that the starting price of bitcoin for these two people is less than $10 / bitcoin
Please note that entities are used instead of people. In the analysis method of this paper, bitcoin wallets that may belong to the same owner are divided into the same entity, which may be not only a person, but also a trading organization like Mt. GOx in addition, through the analysis of the most active entity table given in this paper, the income of the people with the most income (excluding expenses) is less than 700000 BTC. In other words, the person with the most bitcoin will hold no more than 700000 bitcoins. How many people in the world own bitcoins? The paper concludes that as of May 13, 2012, 1.85 million entities hold bitcoin. If we assume that bitcoin users have grown linearly since the advent of bitcoin (January 2009), the current number should be 2.5 million. Because the number of entities is counted on paper, the actual number of bitcoin holders should be a little less than this number, but not much smaller, because after all, there are not many large trading platforms
In addition to the above two problems, [3] also gives many interesting conclusions, such as: < UL >about 55% of bitcoin can be saved without money
in places like GOx mountain, almost all deals are small ones
before May 2012, almost all large single transactions (& gt; 50000 BTC) are subsequent transactions of 90000 BTC on November 8, 2011. There are very strange patterns in this long list of transactions. For example, an entity divides 90000 BTCs into different sizes, sends them back to itself three times, and then sells them on Mt. GOx. 90000 BTCs sold are sent back to the entity through 90 different bitcoin addresses, with 1000 bitcoins per address. These operations indicate that the entity appears to be trying to hide the relationship between these transactions
public key and private key are terms in asymmetric encryption of modern cryptography. They usually encrypt information with public key and decrypt information with private key. Why? Because when you watch TV dramas, telegrams are encrypted symmetrically. The disadvantages of this encryption method are obvious. If someone knows the key and encryption method, they can decrypt the telegrams according to the encryption method. Until asymmetric encryption, the situation has changed. Public key is the key that can be made public all over the world. For example, when you communicate with Google, you encrypt with the 1024 bit public key given by Google and send it to Google. Only he has the corresponding private key, and only he can decrypt it, so the communication security is ensured
2. Bitcoin mainly uses ECDSA, which is the elliptic curve signature algorithm, This algorithm has two characteristics. Note that these two points are very important to the following
A. as long as you know the private key, you can calculate the corresponding public key
B. If you have signed something with the private key, you can use the public key to calculate whether you signed it or not
3. After knowledge preparation, let's start with the transaction of bitcoin. In fact, bitcoin has no wallet, only transaction bills, and the whole bitcoin is a lot of transaction bills
for example:
bill 1 transfers from a to B to XXX bitcoin
Bill 2 transfers from B to C and D to XXX bitcoin
bill 3 transfers from C to e to XXX bitcoin
.... Anyone who downloads the client can receive all the bills from the day when bitcoin was established, so as long as all the bills are downloaded, they will naturally know how much money should be left on each account (think carefully here)
4. The account of bitcoin is the public key mentioned just now
5, Here is the core part!!! Each bill is a piece of data. After you sign it, it will be sent to the whole network, and the data structure will be reversed into easy to understand Chinese. The explanation is as follows:
from (who sent it, including two parts)
previous TX: the ID of the bill for which you want to spend the money, that is to say, any money you spend should have been transferred to you, You need to show the ID of the bill
scriptsig: your signature for this transaction is to hash the bill with your private key, only you can do this hash
to (who accepts, including two parts)
value: how much to send
scriptpubkey: the public key of the other party, and the bitcoin account is a public key
6, How to send it? Bitcoin communication is not so complicated. You can compare it to IRC channel, but different from ordinary "IRC", any client is an "IRC" server. When you start the client, you will receive the client address with public IP around, that is, the "server" list. This list is constantly refreshed, and it is all other bitcoin users, So when you shout a word in this "IRC", people around you will hear it and spread it all over the world
7. After sending the signature to the whole world, all the clients who receive this list will verify whether your signature is correct, whether you sent it, and whether you have so much money (according to the historical transaction, you can calculate how much money you have to spend)
if you have calculated this transaction, it's OK, Basically, the transfer is successful
8. In fact, the other party has accepted bitcoin, but in order to spend it, he must have the private key corresponding to the address (public key). So he can fill in the from header of a form. Previous TX is the serial number of the transaction just now. Scriptsig fills in the hash signed with his private key...
space on datavg<
swap will simply increase I / O reading and writing,
it will have a great impact on the system,
so the memory is big enough...
btw,
brother, do you have any results when applying for sap?