Birthplace of virtual currency

1. The emergence of digital currency was born under the expectation of pursuing a more perfect social and economic transaction mode and Global trade facilitation. It was discovered in the process of using science and technology to graally explore this need. The history of digital currency should start with the creation of bitcoin
the creation of digital currency
the origin of digital currency can be traced back to the 1990s, and electronic gold is one of the best forms. E-gold came out in 1999. It is based on real precious metals. Another consistent digital currency service is LR. Founded in 2006, it is an online payment company in Central America. It allows users to convert U.S. dollars or euros into LR, and only 1% of the transaction cost can be exchanged freely. This kind of two-way service is used by some people to launder money, so it is inevitably shut down by the U.S. government under the charge of money laundering
then, a person named Nakamoto published an article called "bitcoin: a peer-to-peer e-cash system" in the cryptography forum, which gave birth to bitcoin. Compared with legal currency, bitcoin does not have a centralized discoverer, but is generated by the calculation of network nodes, and is composed of a series of complex codes generated by computers. Anyone can dig, buy and sell bitcoin, and it is an anonymous transaction and cannot be tampered with. As a result, it is surrounded by geeks of popular technology, pursuers of complete liberalism and speculators
digital currency can be divided into open mining cryptocurrency and issuing cryptocurrency. Digital currency is defined as an Internet-based currency or exchange medium, which is different from physical currency. Digital currency can realize instantaneous transaction and ownership transfer without borders
for reference.

2. This is where the myth of bitcoin really takes over. According to legend, Satoshi Nakamoto, an unknown person, released an agreement on the digital point-to-point system of decentralized digital currency on October 31, 2008. I urge you to read this short and wonderful paper. While the idea behind bitcoin is revolutionary, it can now begin to make more sense in the context of all other systems, not all of them. Bitcoin proposed blockchain as a synchronous network to solve the probability consensus. According to BFT, from having less than 50% of the total network hash rate of Byzantine rivals Security is achieved in different ways than other historical protocols. Blockchain is designed to support availability rather than consistency, and can support thousands of distributed nodes. The cost of decentralization is much lower throughput in terms of transactions per second (TPS).

3. In the 1980s, a group of talented programmers explored this problem in the password mail group. In 1982, David Chaum proposed an untraceable cryptography network payment system. Eight years later, he extended this idea to cryptology anonymous cash system, namely ecash.
2 in 1998, Wei Dai's paper elaborated an anonymous and distributed e-cash system: B-money. At the same time, Nick Szabo invented bitgold and put forward the workload proof mechanism. Users solve mathematical problems competitively, and then publish the results in series with encryption algorithm to build a property rights authentication system. Hal Finney improved the mechanism as a "reusable workload proof"
3 on the basis of previous work, in 2008, the little-known "Nakamoto Tsung" published "bitcoin: a peer-to-peer cash payment system" in the cryptography mailing list of metzdowd.com. On January 3, 2009, bitcoin network was born, and Nakamoto himself released the first version of open source bitcoin client
since then, the monetary history of mankind has opened a new page.

4. Yes,
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 to issue. It is generated by a large number of calculations based on specific algorithms. 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.

5. Mainstream investment is in BTC, Eth and usdt, and other new currencies and counterfeit currencies emerge one after another. Specific attention can be paid to professional platform.

6. Linux and windows are two kinds of operating systems. For those who operate and maintain the server, when choosing the operating system for the server, is it confusing to choose Linux or windows
in terms of user groups, Linux is a developer centric operating system, while windows is a consumer centric operating system, which is the fundamental difference between the two operating systems. In short, the choice between the two systems depends on whether you develop them or use them as consumers
the advantages and disadvantages of Linux and windows can be summarized as follows
1. Linux can see the source code, but windows can't
the direct result of this point is that the required kernel moles can be tailored and customized in special applications, which is quite beneficial to the optimization of advanced system kernel management and the development of drivers. In addition, because the code is visible, there is no need to worry about malicious functions or backdoors, which is beneficial to the use of military and government enterprises. In addition, when there is a serious problem in the system, you can modify the code by yourself, or you can compile and use it after a few K patches. For windows, you have to wait for a Microsoft patch
2. Linux command line is powerful and can do anything. Windows also has a command line, but it is an accessory
the command line is the foundation of Linux. Even if you are not satisfied with some commands, you can modify or write your own commands. The advantage of the command line is that it is repeatable. To know exactly what the command line is, you can visit old boy ecation. If you want to tell others how to do a thing, you can send a command line to it. If you want to do a thing that you did before again, you can call up the historical command record and execute it again. A lot of things that need to be done regularly are written into scripts. If you set a crontab timer, it's done. In addition, this also ensures that you do the same thing with the same command line
3. Open source and highly customizable
the original intention of open source is not for freedom, but for customization. At & T UNIX has always been righted, but the source code is still available, so that users can modify it according to their needs. Most of the software and systems appreciated by the Linux community follow the same rules - they should be able to adapt to different environments of different users, easily change their behavior, and easily integrate with different environments. Instead of assuming that others are in line with your needs, give them the freedom to customize the system
4. Decentralized
software development also predestinates that the interface and form of the system are not unified because everyone likes to invent wheels. And everyone's wheel is more or less suitable for themselves and the community, rather than everyone. In the Linux environment, no one can force everyone to use their own wheel (except kernel developers, but in fact many distro also have patches on the kernel). Therefore, instead of formulating a practice, Linux allows users to choose a way of life
you can see that there are a large number of distros in the Linux ecosystem. Different distros have different init modes, different package managers and installation strategies; Everyone's habit of using different VCs, different shells and different editors is the embodiment of more choice philosophy
5. Linux is based on the network and was born in the network
when you connect to SSH remotely, you can easily control the Linux server thousands of miles away. As long as you have the corresponding permissions, it's almost the same as sitting in front of a physical machine. Even if the network speed is poor, it's just some encrypted characters being transmitted, and the bandwidth required is very small.

7.

The earliest currency in China was seashell. Seashells are often found in the prehistoric Yangshao culture, Longshan culture, Dawenkou Culture, Erlitou culture and tombs of Shang and Zhou dynasties

there is also a record of "xuanbei after the summer" in the wrong coin of Yantielun. Seashells are proced from the warm sea in the south of the distant exchange of goods, is a beautiful and precious decoration. It can be traced back to the Xia Dynasty, when China entered the class society and the state came into being. In Shang Dynasty and Western Zhou Dynasty, it was the main currency in circulation

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I. currency of the spring and Autumn Period

1. Dishonoured cloth: it circulates in Guanluo Sanjin area, and "Zhou, Zheng, Jin and Wei" are mainly flat and sharp dishonoured cloth

Dao Hua (goods): circulated in the eastern Qi State, imitating a proction tool

(3) ant nose money: copper imitation shell circulating in southern Chu state

Second, the currency of the Han Dynasty. Gold is the upper currency, and copper is the lower currency. It is still the legal currency unit. The unit is changed from long to Jin, and 1 jin = 10000

2. In the period of Emperor Wu of Han Dynasty, there were gold (round) and gold (oval) in imitation of Qilin horseshoe

In the Western Han Dynasty, gold was mainly used for rewards and gifts. Wang Mang nationalized gold, but after the Eastern Han Dynasty, gold was reced, and silk, cloth and copper coins were used for rewards

8. As for the origin of money, paper money is a common form of money in the world. The earliest paper money in the world is Jiaozi in Cheng, Sichuan Province in the Northern Song Dynasty. China is the first country in the world to use currency. According to the literature records and a large number of unearthed cultural relics, the origin of Chinese currency has a history of at least 4000 years. The development of Chinese currency culture has a long history, from the original shell coin to cloth coin, knife coin, round coin, ant nose coin and fangkong coin popular after the unification of China by the first emperor of Qin Dynasty. In the Northern Song Dynasty, jiaozi appeared in China. The emergence of paper money is a great progress in the history of money. Some people think that the origin of Chinese paper money can be traced back to the "white deer skin money" of Emperor Wu of Han Dynasty and the "flying money" of emperor Xianzong of Tang Dynasty. During the period of Emperor Wu of Han Dynasty, the National Treasury was empty because of the long-term war with Xiongnu. In order to solve the financial difficulties, the "three baht coins" and "white gold coins" (alloy coins made of silver and tin) were coined, and the "white deer skin coins" were issued at the same time. The so-called "white deer skin coin" uses the white deer skin of the palace as the coin material. Each piece is one square foot, and the surrounding color is painted. The value of each piece is 400000. Because its value is far away from its own value, the "white deer skin coin" is only used as a tribute between kings and princes, not used in the field of circulation, so it is not a real sense of paper money, only a pioneer of paper money“ "Feiqian" appeared in the middle of Tang Dynasty. At that time, when merchants went out to do business with a large amount of copper money, there were many inconveniences. They first went to the official to issue a certificate, which recorded the place and the number of coins, and then went to other places to withdraw money and buy goods with the certificate. This certificate is called "feiqian"“ In essence, "flying money" is only a kind of exchange business. It does not intervene in circulation and does not function as currency. Therefore, it is not paper money in the real sense. In the Northern Song Dynasty, "Jiaozi" in Cheng, Sichuan Province was the beginning of real paper money. It is not accidental that paper money appeared in the Northern Song Dynasty, it is the inevitable proct of social, political and economic development. The commodity economy developed rapidly in Song Dynasty, and more money was needed in commodity circulation. However, the shortage of copper money at that time could not meet the demand in circulation. At that time, the iron coin was used in Sichuan area, which was of low value and heavy weight, and was extremely inconvenient to use. At that time, one copper coin was worth ten iron coins. The weight of one thousand iron coins was 25 Jin for a large coin and 13 Jin for a medium coin. It costs 20000 yuan to buy a piece of cloth. It weighs about 500 Jin. It takes a car. Therefore, we need light money objectively, which is the main reason why paper money first appeared in Sichuan. Moreover, although the Northern Song Dynasty was a highly centralized feudal autocratic country, the national currency was not unified, and there were several currency areas, which were independent and not universal. At that time, there were 13 routes (administrative units in Song Dynasty) dedicated to copper coins, 4 routes dedicated to iron coins, and Shaanxi and Hedong used both copper and iron coins. The use of paper money can prevent the outflow of copper and iron money. In addition, the Song Dynasty government was often attacked by Liao, Xia and Jin Dynasties, and the military expenses and reparations were very large. It also needed to issue paper money to make up for the fiscal deficit. Various reasons contributed to the emergence of "Jiaozi". The first jiaozi was issued freely by merchants. In the early years of the Northern Song Dynasty, "Jiaozi shop" appeared in Cheng, Sichuan Province, which specialized in keeping cash for merchants carrying huge sums of money. The depositor delivers the cash to the shop owner. The shop owner temporarily fills in the amount of cash deposited by the depositor on a roll made of paper, and then returns it to the depositor. When the depositor withdraws the cash, he pays the shop owner the interest of 30 Wen, that is, 3% of the deposit fee. This paper voucher which temporarily fills in the deposit amount is called "Jiaozi". At this time, "Jiaozi" is just a kind of certificate of deposit and withdrawal, not currency. With the development of commodity economy, "Jiaozi" has been used more and more widely. Many merchants set up jiaozi shops which specialize in issuing and exchanging "Jiaozi", and set up jiaozi sub shops in various places. Due to the fact that jiaozi shop owners abide by the credit and take it as they come, the printed "Jiaozi" pattern is exquisite, it is hidden as a mark, there are mistakes between black and red, and it is difficult for others to forge their own words, so "Jiaozi" has won a high reputation. In order to avoid the trouble of carrying coins, there are more and more cases of large-scale transactions between merchants who directly use "Jiaozi" to pay for money at any time. It is in the repeated circulation process that jiaozi has graally acquired the character of credit currency. Later, jiaozi shop owners found that only using part of their deposits would not endanger the reputation of Jiaozi. So they began to print jiaozi with uniform denomination and format, which was issued to the market as a new means of circulation. This kind of "Jiaozi" has been the symbol of coins, and has really become paper money. However, jiaozi was not recognized by the government at this time, and it was still a private issue. But not all jiaozi shops are law-abiding and trustworthy. There are some greedy shop owners who are greedy for profits, who cheat maliciously and shut down their business after they have made excessive payments; Or misappropriate deposits, run other business failure and bankruptcy, so that the "Jiaozi" can not be cashed. In this way, when depositors can't withdraw money, they often cause trouble and litigation. Therefore, ring the reign of Jingde (1004-1007), Zhang Yong, the governor of Yizhou, reorganized jiaozi shops, eliminated outlaws, and managed them exclusively by 16 wealthy merchants. So far, the issue of Jiaozi was approved by the government. In the first year of Tiansheng (1023) of emperor Renzong of the Song Dynasty, the government set up jiaozi business in Yizhou. One or two officials of the Jing Dynasty acted as supervisors to preside over the distribution of Jiaozi, and "set up a papermaking house to eliminate the disadvantages of forgery" to strictly control the printing process. This is the earliest paper money officially issued by the government in China - "guanjiaozi". It issued paper money 600 or 700 years earlier than the United States (1692), France (1716) and other western countries, so it is also the earliest paper money in the world“ In the early stage of the issue of guanjiaozi, its shape was modeled on the private relationship among the people, and stamped with the seal of the state, but the amount of money temporarily filled in was different, generally from one to ten, and the scope of circulation was specified. In the reign of emperor Renzong of the Song Dynasty, it was changed into five Guan and ten Guan. By the time of emperor Shenzong of the Song Dynasty, it was changed to two kinds: Yiguan and wuwuwen. There are also restrictions on the amount of issue. It is stipulated that the issue shall be divided into three years (two years in full) for each sector, and the new one shall be exchanged for the old one. The first jiaozi issue was 1 256 340 units, with a reserve capital of 360 000 units (taking Sichuan tieqian as the note capital), and the reserve was equivalent to 28% of the issue“ The circulation scope of Jiaozi was basically limited in Sichuan. Later, although it was popular in Shaanxi and Hedong, it was soon abolished. In 1107, the Song government changed jiaozi to qianyin and jiaoziwu to qianyin. In addition to Sichuan, Fujian, Zhejiang, Huguang and other places still use "Jiaozi", other roads use "qianyin". Later, Sichuan changed jiaozi to qianyin in 1109“ The biggest difference between "Qian Yin" and "Jiao Zi" is that it takes "Luo" as the unit“ The paper, printing, picture and seal of "Qian Yin" are excellent. But "Qian Yin" did not buy notes, and was not allowed to exchange them, so the value of paper vouchers dropped sharply. In the Jiading period of the Southern Song Dynasty, each coin was only worth 100 Wen in cash“ The emergence of "Jiaozi" has facilitated commercial exchanges and made up for the shortage of cash, which is a great achievement in the history of currency in China. In addition, "Jiaozi", as the earliest banknote issued in China and even in the world, also occupies an important position in the history of printing and printmaking, which is of great significance to the study of ancient banknote printing technology in China. On the history of currency development, China is one of the earliest countries in the world to use currency, with a history of 5000 years. In the process of its formation and development, ancient Chinese currency has undergone six major evolutions: first, the evolution from natural currency to artificial currency. In Chinese characters, most of the characters related to value have changed from "Bei". From this we can see that Bei is the earliest currency in China. With the rapid development of commodity exchange, the demand for money is increasing. Seashells have been unable to meet people's needs. People began to imitate seashells with copper. The appearance of copper shell is an important evolution from natural currency to artificial currency in ancient Chinese currency history. With the extensive use of artificial coins, seashells, as a natural currency, graally withdrew from China's currency stage. 2、 From the appearance of Tongbei in Shang Dynasty to the Warring States period, China's currency graally formed four systems characterized by the domination of the feudal lords, namely, shovel coin, Dao coin, ring coin and Chu coin (yuan Jin and Yi Bi Qian). After Qin unified China, the first emperor of Qin promulgated the earliest currency law of China in 210 BC, which stipulated that half Liang coins with round square holes of Qin state could be used throughout the country. The circulation of Qin banliang coins with round square holes in the whole country ended the disordered state of different shapes and great weight differences of ancient Chinese coins, which was a significant evolution from disordered shape to standard shape in the history of ancient Chinese coins. The shape of this round square hole determined by the Qin banliang coins continued until the early Republic of China. 3、 The evolution from local coinage to central coinage according to the records of Shi Huo Zhi in the book of Han Dynasty, after the founding of the Han Dynasty, Liu Bang allowed the people to make coins privately. The gentry, the rich businessmen and the local forces took advantage of the opportunity to make money. In the reign of Emperor Wen, "Dr. Deng Tong also made money for the king." In the fourth year of Yuanding (1115 years ago), Emperor Wu of the Han Dynasty took back the minting right of the prefecture, and the central government minted five baht coins. From then on, it was determined that the central government should be responsible for the unified management of coin casting and issue, which was a significant evolution from local coin to central coin in the history of ancient Chinese currency. Since then, the central government has been in charge of the coinage. The return of the minting right to the central government played an important role in stabilizing the political situation and economic development of the dynasties. 4、 The evolution from the weight of documents to Tongbao and Yuanbao coins since the Qin and Han Dynasties are usually clearly marked with the weight of money, such as "half Liang", "five baht", "four baht" and so on (24 baht is one or two). In the fourth year of Wude (621), Emperor Gaozu of the Tang Dynasty, Li Yuan decided to reform the currency system, abolish the ancient coins of different weights, and cast "Kaiyuan Tongbao" coins with the meaning of "opening up a new era". Kaiyuan Tongbao is a change from the weight of documents to Tongbao and Yuanbao in ancient China. Kaiyuan Tongbao coin is the earliest Tongbao coin in China. Since then, copper coins in China no longer use money to mark the weight, but use Tongbao and Yuanbao. It has been used until the "Tongbao of the Republic of China" after the 1911 Revolution. 5、 In the Northern Song Dynasty, e to the shortage of copper materials, the government made a large number of iron coins in some areas to make up for the shortage of copper coins. According to the records of the history of Song Dynasty, the cast iron coins in Sichuan at that time always weighed 25 Jin and 8 Liang. To buy a piece of silk in Sichuan, you have to pay 130 Jin of iron. Iron money is so cumbersome and inconvenient that paper money jiaozi came into being in Sichuan. The appearance of Jiaozi is an important evolution from metal currency to paper currency in ancient Chinese currency history. Jiaozi is not only the earliest banknote in China, but also the earliest banknote in the world. 6、 In the late Qing Dynasty, with the graal introction of foreign advanced science and technology, people began to buy coin making machines abroad in Guangxu period to make silver and copper coins. Later, Guangdong began to use machines

9. If a nurse leaves the hospital, going to the confinement center is also very promising. First of all, he has some nursing foundation, and then he learns some knowledge about how to take good care of children or pregnant women. He is very comprehensive, and his future is also very big

10. Toobi, for many years, it can't be a pit