How many HDA digital currencies

1.

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

2. I can't give you an accurate answer to this question because digital currency covers too many aspects. There is also the possibility that many new cryptocurrencies are born or die every day. Now the world's more well-known digital currencies are bitcoin, dogcoin, Leyte coin, bitstock, reborn coin, Yuanbao coin, Diandian coin and so on. It is said that Ecuador, a small South American country, recently created its own official cryptocurrency
according to incomplete statistics, more than 200 counterfeit coins have been proced since 2014, and more than 100 have survived. The life cycle of Shanzhai coin is generally about 2-3 months. Because the purpose of some Shanzhai coins is to earn money without any innovation. When the price is high enough, the makers will sell a lot to cash out. Without the support of the makers, this kind of counterfeit money will eventually die.

3. One of the controversial attributes of bitcoin is its fixed supply. At present, 25 new bitcoins are proced every 10 minutes, and the number is halved every four years. Overall, there won't be more than 21 million bitcoins & gt;. On the other hand, each bitcoin can be divided into 100 million shares (each is called 1 "cong"), if one cent is enough to buy a car, it will be troublesome to trade in US dollars, but even if bitcoin rises to the level of US dollars assumed above & gt; We will not encounter such problems. Therefore, in short, the total number of monetary units that will always exist is 2100 billion, that is 2100 trillion, or 250.899. In the square of choosing this value & gt; In fact, Nakamoto is much luckier or smarter than most people realize. First of all, 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, & gt; The value will return to zero like a odometer
secondly, however, there is a smaller threshold for the total number of "smart": the largest possible integer that can be represented in floating-point format. Integers are not the only numbers that computers can store; To deal with decimals, computers & gt; Use a format for floating point representation. Floating point notation is essentially a binary version of scientific notation. For example, here is a value you will encounter when you study physics:
mass of the earth: 5.972 1024 kg
mass of the sun: 1.989 1030 kg
speed of light: 2.998 108 M / s
light year: 9.460 1015 m
mass of proton: 1.672 10-27 kg
Planck length: 1.616 10-35 m
we can notice that, How does scientific notation allow you to represent all of these values with reasonable accuracy, even though they vary greatly in size. Floating point notation is essentially a binary scientific notation; When you store numbers & gt; When the word is 9.625, what your computer stores is "1.001101
* 1011" (in other words, it stores 0100000000100011
& gt; This is the same thing with high-precision sequence form). In this high-precision form, the coefficient (that is, the part that is not the exponent) has 52 bits. This means high precision (more refined & gt; Double precision floating point number is enough to store up to 253 numbers, but it can't be any higher. If it exceeds 253, you have to start cutting off the numbers at the end. Bitcoin's 250.9, the total number of "smart" in the form of index, is just & gt; OK, below this maximum
if we have integers, why should we care about floating-point values? Because more high-level programming languages (such as JavaScript) do not open low-level "floating point" and "integer representation", but only provide "number" representation for programmers; Concepts
– of course, in floating-point form. If Nakamoto chose 210 million instead of 21 million at that time, bitcoin programming in many languages would be much more troublesome than it is now
note that Stefan Thomas unfortunately didn't notice this in time when he wrote bitcoinjs, so that the library used a special "big number big
number" object instead of an ordinary number to store the tutorial output value; My own bifurcated bitcoin JS (along with other improvements) uses ordinary numbers.

4. Digital currency is an unregulated and digital currency, which is usually issued and managed by developers and accepted and used by members of a specific virtual community. The European Banking authority defines virtual currency as a digital representation of value, which is not issued by the central bank or authorities, nor linked with legal currency. However, because it is accepted by the public, it can be used as a means of payment, or it can be transferred, stored or traded in electronic form
China: actively and steadily promote the implementation of the research on the central bank's digital currency
as early as 2014, the central bank set up a special research group on the issue of legal digital currency to demonstrate the feasibility of the central bank's issue of legal digital currency< On October 28, 2019, Huang Qifan, vice president of China Center for international economic exchange, said: "the people's Bank of China has studied DC / EP for five or six years, and I think it has become mature. The people's Bank of China is likely to be the first central bank in the world to launch a digital currency. "
on November 28, fan Yifei, vice governor of the people's Bank of China, said at the forum that at present, the central bank's legal digital currency DC / EP has basically completed the top-level design, standard formulation, function research and development, joint debugging and testing under the premise of adhering to double-layer delivery, M0 substitution and controllable anonymity. In the next step, we will follow the principle of steady, safe and controllable, reasonably select the pilot verification area, scene and service scope, continuously optimize and enrich the DC / EP functions, and steadily promote the introction and application of digital legal tender< European Central Bank: exploring the form and possibility of CBDC. 'we are analyzing what form CBDC may take in order to achieve its potential purpose and mitigate its potential negative impact on monetary stability and financial intermediation,' Mr. kindos said. On the stable coin, Mr jindos said that it was very uncertain whether the stable coin could deliver on its promise, and it was clear that it could bring risks to consumers and the financial system. So it is understandable that authorities around the world are calling for regulatory stability.

5. It shows that the total amount of this kind of digital currency is relatively large, and the total amount of many digital currencies is as high as 10 billion. The circulation of some MLM coins is not constant and can be increased or split at will. Moreover, there are many different digital currencies in the world, and the number of each digital currency is very considerable
the well-known digital currencies in the currency circle include bitcoin, Ruitai coin, Laite coin, doggy coin, etc.

6. Chinese digital currency should refer to Chinese currency, the specific amount of this currency is not clear. However, many things of this kind of coin are fabricated, not real. And its related companies are mostly forged. Now the Chinese currency has basically disappeared, it is estimated that it should be dead

is it a reliable currency? Just compare it with the mainstream currencies such as bitcoin, Leyte, decent and ether.

7. At present, these currencies are all classified as MLM currencies in China, so it is not recommended to participate in them.

8. The total amount of money in DCEP is not constant

why

let's take a look at the current definition of DCEP

Digital legal tender

in addition to being different from legal paper money in carrier, it has the same function as paper money: value scale, circulation means, payment means and value storage

this is also the function of paper money

the issuance of DCEP is based on 100% reserve and will circulate with cash currency, that is, M0 issuance

although the central bank's digital currency was slowly launched after the rise of blockchain technology, it is not pure blockchain technology, but only uses some technologies related to blockchain

we all know that the commercial application of block chain technology still faces many problems, such as concurrency, data storage and so on

a country with a large population like ours, if we use blockchain technology in a strict sense, it will not be able to carry it at present<

Wanxiang blockchain analysis:

from the information disclosed by the people's Bank of China, DC / EP does not use the real blockchain like Libra

although digital currency is not a token in the blockchain, it is similar to the token in the blockchain in the key features of non double flower, anonymity, unforgeability, security, transitivity, separability and programmability

therefore, DC / EP still belongs to token paradigm rather than account paradigm

the central bank is responsible for the maintenance of the DC / EP issuance registration subsystem, which is centralized and does not need to run consensus algorithm, so it will not be subject to the performance bottleneck of the blockchain

in DC / EP, blockchain is used to confirm the right registration of digital currency and plays an auxiliary role

each country's base currency issuance is increasing every year

therefore, the central bank's digital currency improves the bearing property of money. Paper money is naturally suitable for the atomic world, and digital currency is more suitable for the consumption scenarios in the bit world

the supply is definitely the same as that of the previous monetary system, increasing every year.

9. Mining is mainly enough graphics card, memory and CPU requirements are not high. The problem is that the graphics card needs at least gtx1060. And generally use the graphics card shelf, with six graphics cards at a time, so the motherboard requires six graphics cards and six graphics card slots, or use the adapter card to drive six graphics cards
in addition, the power consumption of the mining machine is very serious. If you turn on the machine 24 hours a day, you may not be able to earn back the electricity bill at home
Mining studios are usually built in remote places where there are private small hydropower stations, because the electricity price of private small hydropower stations is low.