Virtual currency and quantum computer

1. Alipay and so on are only electronic payment methods. The money used in the transaction is coming through bank accounts, that is, the money in Alipay actually corresponds to a banknote, and the digital money is money. In the actual use experience, digital money and electronic payment may feel similar, but they are still quite different in essence
digital currency is also different from virtual currency. For example, the well-known Q coin and the money recharged in various games are virtual currency. These virtual currencies can only be purchased with real currency, but cannot be converted into real currency
in the world, bitcoin is probably the most famous digital currency. In addition, there are "Wright coin", "Dog Coin" and "Yuan Bao coin" in China.

2.

Virtual currency is the currency used for electronic circulation. Now the scope of virtual currency is very large, including q-coin, bitcoin and so on. With the development of digital currency, virtual currency is becoming more and more abundant, which may become the mainstream in the future. For example, BTC, EOS, bcbot and so on are not only virtual currencies, but also algorithms, landing projects and technologies

virtual currency is mainly issued by online game service providers to purchase game props, such as equipment, clothing, etc. But at present, the use of virtual currency has gone far beyond this category. Virtual currency can be used to buy game cards, physical objects and download services of some movies and software

extended data:

real risk

as the proct of e-commerce, virtual currency has begun to play an increasingly important role, and it is more and more connected with the real world. However, with the growth of virtual currency, the relevant laws and regulations are lagging behind, which has laid many hidden dangers

fraud

the private transaction of online virtual currency has realized the two-way circulation between virtual currency and RMB to a certain extent. The activity of these traders is to buy all kinds of virtual currencies and procts at a low price, and then sell them at a high price to earn profits. With the increase of such transactions, there are even virtual mints. In addition to the virtual currency provided by the main company, there are also some people who specialize in "virtual coin making" to obtain virtual currency by playing games and then resell it to other players

Taking Wenzhou as an example, there are about seven or eight such "virtual mints" with four or five hundred practitioners. This not only creates a bubble for the price of the virtual currency itself, but also causes trouble for the normal sale of the issuing company. It also provides a platform for selling and collecting money and money laundering for various cyber crimes. p>

impact system

in modern financial system, the issuers of money are generally central banks, which are responsible for the management and supervision of money operation. As the equivalent exchange goods used to replace the real currency circulation on the Internet, the virtual currency on the Internet is essentially the same as the real currency. The difference is that the issuers are no longer central banks, but Internet companies

if the development of virtual currency makes it form a unified market, each company can exchange with each other, or virtual currency is integrated and unified, and all of them are based on the same standard and price, then in a sense, virtual currency is currency, which is likely to form a threat impact on the traditional financial system or economic operation

reference: network virtual currency

3. Here's bitcoin
bitcoin price has been cut by the waist
how to implement blockchain application is still the main problem. In addition to bitcoin, the large-scale application of blockchain in other scenarios has not yet reached the commercial stage. Looking back to the second half of 2017, the price of bitcoin almost reached a new high every day, and finally reached the peak in the South Korean exchange with the highest premium in the world - about 140000 yuan per piece. On June 3, 2018, as of press time, coinbase bitcoin trading platform quoted 49688 yuan, and the price of bitcoin has been cut. Since the beginning of this year, the price of bitcoin has rarely seen eye popping ups and downs, and the overall trend of monthly decline
bitcoin development status
according to the data of the in-depth analysis report on business model innovation and investment opportunities of the blockchain instry released by the foresight Instry Research Institute, bitcoin prices showed a downward trend in May, with the overall market value falling from US $157.3 billion at the beginning of the month to US $127.4 billion at the end of the month, a decrease of 19%; In addition, there are 444000 active addresses and 197000 transfers per day. From the trend point of view, the number of active addresses and daily transfers are positively correlated with the transaction price. In May, the overall trend is volatile, and the downward trend is very obvious
reasons for the steady decline of bitcoin in the past half year
how to understand the "steady decline" of bitcoin in the past half year? There are two main reasons: firstly, the most important reason is that institutional investors and speculators who have accumulated a large number of "profit" are cashing in their profits and leaving the market; Secondly, before the blockchain instry has no real application and profit model, the rise of bitcoin price can only be regarded as speculative speculation. In addition, it is an undeniable fact that the Central Bank of China has made a decisive move to close the bitcoin trading platform, which has achieved remarkable results in preventing bitcoin speculation
at present, the domestic bitcoin exchanges have basically moved to foreign countries, which has nothing to do with China. Investors operate on those platforms at their own risk
the current market is not very good. Only when the market is good, can investors find ways to participate in bitcoin investment. As the total market value of the coin circle is still small, with more blockchain applications, there is still potential in the future
over consumed blockchain
e to the "tepid" price of bitcoin, blockchain, as its underlying technology, has reached the level of "known to all women and children", and even surpassed bitcoin in recent years
recently, a series of related reports are suspected of making up for the number and full of hype, and blockchain has obviously been over consumed. In addition to bitcoin, the large-scale application of blockchain in other scenarios has not yet reached the commercial stage
with the graal deepening of the understanding of blockchain technology, domestic enterprises have laid out blockchain technology, platforms and applications, including Internet enterprises such as network, Tencent, Ali, Jingdong, Netease, major banks, financial enterprises such as Ping An of China and Huawei. In terms of application, China actively explores and promotes blockchain + applications in the form of alliance chain and private chain to help solve the pain points of related instries, improve efficiency and rece costs.

4.

The differences between e-money and virtual money are as follows:

1. Electronic money refers to using a certain amount of cash or deposit to exchange from the issuer and obtain data representing the same amount, or through the quick payment service launched by the bank and the third party to transfer the balance in the bank through some electronic ways, so that transactions can be carried out. Strictly speaking, it is a kind of currency that consumers use the bank's Internet banking service to store value and make quick payment to the issuers of electronic currency, and make consumers trade electronically through media (two-dimensional code or hardware equipment)

Virtual currency refers to non real currency. Well known virtual currencies, such as online currency of Internet company, q-coin of Tencent company, q-point and voucher of Shanda company, micro currency launched by Sina (used for micro games, Sina reading, etc.), chivalrous Yuanbao (used for chivalrous road game), silver grain (used for bixue Qingtian game), and popular digital currencies in 2013 include bitcoin, Laite coin, infinite coin, quark coin, zeta coin, etc Barbecue coins, pennies (Internet), invisible gold bars, red coins, prime coins. At present, hundreds of digital currencies are issued all over the world. Popular in the circle & quot; The legend of "bitcoin, Wright silver, infinite copper, pennies aluminum"

The detailed explanation of electronic currency is as follows:

1. Concept: it is an encrypted serial number representing cash, which can be used to represent the currency value of various amounts in reality. With the transformation from paper-based economy to digital economy, e-cash will become the mainstream

2. Features: anonymity, transaction cost saving, transmission cost saving, low holding risk, flexible and convenient payment, anti-counterfeiting and anti repetition, non traceability

There are two kinds of e-cash: one is based on the Internet and keeps the binary data representing the value of money in the hard disk of the computer terminal; One is the electronic wallet that keeps the monetary value in the IC card and can be circulated without the bank payment system

4. Definition: consumers pay traditional money to the issuers of electronic money, and the issuers store the equal value of traditional money in the electronic devices held by consumers in electronic form

5. With the development of the Internet, while providing a large number of free services to the majority of Internet users, according to the company's profit needs and the diversified needs of users, various websites have launched charging services. This also promoted the emergence of virtual currency
in order to provide better services, many portal websites and online game operators have been providing virtual currency for use for a long time. According to incomplete statistics, there are no less than 10 kinds of network virtual currency (referred to as network currency) currently in circulation, such as Q currency, network currency, cool currency, Warcraft currency, Paradise currency, Shanda (game area) coupon, etc. Take Q coin as an example, there are more than 200 million users. Instry insiders estimate that the domestic Internet has a virtual money market scale of several billion yuan per year, and is growing at a rate of 15% - 20%
in a market economy, demand stimulates innovation, which in turn stimulates demand. The increasing popularity of virtual currency is completed in the needs of users and the innovation of enterprises. At present, there are many kinds of virtual currency in China's network market, among which Tencent, relying on its huge QQ users, has timely launched QQ currency with the maturity of instant messaging market
it is undeniable that virtual currency makes us feel the convenience of purchasing network services, which is the inevitable proct of the development of network economy. But at present, the network virtual currency has quietly changed into a huge trading market
Lyndon larush, a famous American economist, once predicted that from 2050, the virtual currency of the Internet will be officially recognized to some extent and become a mobile currency. With such a large market and bright prospects, many companies are eager to try and intend to occupy this market. Now it seems that the network, PayPal (PayPal) and Tencent are in the leading position
at the present stage, most e-money is based on the existing real money (cash or deposit), which has the function of "value measurement" and "value preservation", and the precondition that e-money and real money can exchange at a ratio of 1
: 1 is established
as a means of payment, most e-money can not be separated from cash or deposit. It is transmitted and transferred by electronic means to pay off creditor's rights and debts and realize settlement. Therefore, the function and influence of e-money at present is essentially the relationship between e-money, cash and deposit
at present, there are four types of popular electronic currency in China
1. Stored value card electronic currency. Generally, it appears in the form of magnetic card or IC card. Besides commercial banks, it is also issued by telecommunication departments (ordinary telephone card, IC telephone card), IC enterprises (network card), commercial retail enterprises (various consumption cards), government organs (internal consumption IC card) and schools (Campus IC card). After the issuer receives the customer's funds in advance, it issues the equivalent stored value card, which makes the stored value card a new "deposit account" independent of the bank deposit. At the same time, the stored value card in the customer consumption to dect the way to pay fees, which is equivalent to the deposit account payment currency. At present, the deposits in the stored value cards are not included in the central bank's reserve requirements. Therefore, the stored value cards can rece the demand for cash and current savings
2. Credit card applied electronic currency. It refers to the credit card or quasi credit card issued by commercial banks, credit card companies and other issuers. The loan can be consumed within the credit limit specified by the issuer, and then the repayment can be made at the specified time. The widespread use of credit cards can expand consumer credit and affect money supply
3. They are mainly debit cards, electronic checks, etc., which are used to withdraw cash, transfer settlement and transfer funds from bank deposits in an electronic way. The widespread use of this kind of electronic payment method can rece the cost of consumers to and from the bank, rece the balance of cash demand, and speed up the circulation of money
4. Cash analog electronic currency. There are mainly two kinds: one is e-cash which is based on the Internet environment and keeps the binary data representing the value of money in the hard disk of the computer terminal; One is the electronic wallet that keeps the monetary value in the IC card and can be circulated without the bank payment system. This kind of e-money has the characteristics of anonymity of cash, can be used for payment between indivials, and can change hands many times. It is developed for the purpose of replacing entity cash. The expanding use of this kind of electronic currency can affect the currency issuing mechanism, rece the seigniorage income of the central bank, and rece the scale of assets and liabilities of the central bank

6. Digital currency
unlike virtual currency, digital currency is neither bitcoin nor q-coin! That is to say, it is different from virtual currencies such as bitcoin and Ethernet
virtual currency can only be closed in circulation on the network, just like Tencent's q-coin and Huixin cloud software collaborative instry ecological chain platform, they can only be used for their own procts. Digital currency can be used for real goods and services transactions, but only the digital currency issued by the state is legal digital currency, bitcoin is illegal digital currency. As for legal digital currency, there is no unified international definition. Yao Qian, deputy director of the science and Technology Department of the people's Bank of China and head of the preparatory group of the digital currency Research Institute, believes that the digital currency researched and issued by the people's Bank of China is indexed RMB. From the perspective of national schemes, it belongs to legal encrypted digital currency, which is not only a payment tool but also a currency. Correspondingly, virtual currency is also called illegal fixed digital currency. Li Lihui, head of the blockchain working group of China Internet Finance Association, once said that digital currency must have legal status, national sovereignty endorsement, and clear responsibility subject of issuance. Virtual currencies represented by bitcoin and ethereal currency have no country, no sovereign endorsement, no qualified issuers, and no national credit support. These are not digital currencies
digital money is not equivalent to virtual currency
since digital money can be used for commodity trading, is Alipay and WeChat payment a kind of digital currency?
Alipay, WeChat payment and mobile phone banks are all electronic money, not digital money. These are all payment methods based on electronic accounts, which are in essence just a process of informatization of legal currency, not digital currency in a strict sense. For example, the amount of Alipay or WeChat transactions is essentially banknotes on bank accounts, but it is electronic form. The "100 yuan" displayed on the mobile phone will correspond to the real 100 yuan in the bank.
(edited by Huixin Yunxu)

7. How can I not show you my mother but still prove that my mother is my mother
zero knowledge proof is a technology that the verifier can make the verifier believe a certain conclusion is true and credible without providing the verifier with the information itself. At present, the anonymous transaction of zcash, a digital asset with outstanding anonymity, is realized by "zero knowledge proof"
for example, a has to prove to B that he has the key to a room. Suppose that the key can only be used to open the lock of the room, but no other method can. At this time, a can choose to give the key to B, and B can use the key to open the lock of the room, so as to prove that a has the correct key of the room
or a opens the room with the key, takes an object out of the room and shows it to B. B knows that the object is only in the room. The principle of method two is zero knowledge proof
zero knowledge proof can prove that I know the secret without disclosing the information itself, and can effectively solve many verification problems.

8. Abstract: in a small laboratory in a secluded village 50 miles north of New York City, intricate pipelines and electronic equipment are wound under the ceiling. This seemingly haphazard pile of devices is a computer. It is different from any computer in the world, but it is a milestone device in the history --- quantum computer

on May 3, 2017, a big news in science and technology circles: the world's first optical quantum computer surpassing the early classical computer was born. This "world's first" is a genuine "made in China" and is the result of a breakthrough made by Professor Pan Jianwei and his colleagues of the University of science and technology of China and Professor Wang Haohua of Zhejiang University
if the speed of traditional computer is bicycle, the speed of quantum computer is just like airplane. In the past few months, IBM and Intel have announced that they have built 50 and 49 qubit quantum computers, respectively. Some experts point out that within ten years, the computing power of quantum computer may catch up with and surpass the current supercomputer

at the American Physics Annual Meeting held in Los Angeles on March 5, 2018, Julian Kelly, a research scientist at Google quantum AI laboratory, reported that he was leading the Google team to test a 72 qubit universal quantum computer. However, this is only 72 qubits. At this rate of development, the magic power of quantum computer will soon be terrifying
then, why do we say that quantum computers can easily crack bitcoin? What's the matter
it takes 600000 years to crack an RSA cryptosystem, but it takes less than three hours to use a quantum computer with considerable storage function! In other words, with the leap from electronic computer to quantum computer, the computing power and the ability to process big data of the whole mankind will be improved for tens of thousands or even hundreds of millions of times. In front of the quantum computer, the traditional electronic computer we used to be proud of is equivalent to the previous abacus, which is bulky and old

although the bitcoin protocol uses asymmetric cryptocurrency, the corresponding public key is used to verify the transactions signed by the private key to ensure that bitcoin can only be used by legitimate owners. It is not feasible to force the private key to be consistent with the public key by using the currently available computer, but quantum computer can solve the problem of asymmetric cryptocurrency
in addition, the rule of bitcoin is that the more processed block will be added to the blockchain, and the other block will be voided. For example, it's like 51 people in an account book say that you have saved 100 yuan in the bank, while 49 people say that you have saved 50 yuan. In this case, the minority of blockchain algorithm is subordinate to the majority, and the bank thinks that you have saved 100 yuan is true, and that you have saved 50 yuan is false. So once a miner has 51% of the computing power, other subsequent miners will not be able to continue to get bitcoin

Andersen Cheng, co-founder of a network security company in the UK, says bitcoin will come to an end the day quantum computers come into use. What's your opinion?

9. In fact, the threat of quantum computers to bitcoin is not mining, but trading attacks. We know that the transaction of bitcoin is completed by decentralized cryptography authentication, and the core of this authentication method is hash algorithm. If there is a quantum computer, it can create collisions (Grover algorithm, polynomial acceleration) to forge transactions for profit. Because the core algorithm of bitcoin has been fixed, if the algorithm is not changed, the key length cannot be increased, and this attack cannot be resisted. However, if there is a practical quantum computer, what can we do is better than this kind of attack...
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