Price list of virtual currency in recent years

10. This article will not deal with the details of algorithms and protocols. I plan to write another article on the principle of bitcoin from the perspective of programmers, where I will explain some key data structures, algorithms and protocols in the bitcoin system from the perspective of technicians
in this article, I will give a virtual village called "bitcoin village". The whole article will tell you the motivation of bitcoin, what problems it has solved, and the goals and design schemes of some key components step by step in the way of storytelling
question
let's start with the motivation of bitcoin< In this world, there is a small village called bitcun, which has hundreds of families. The village is almost isolated from the world and lives on its own. Because there is no large-scale trade, the villagers of Biti village have been living a barter life. That is to say, there is no unified currency among the villagers. The trade between the villagers is basically that Lao Zhang's family exchanges a bag of flour for Lao Li's family's sheep, and Wang's sister-in-law exchanges a basket of wild fruits for Aunt Liu's two feet of cloth. The villagers have been living a simple life<

physical currency
finally one day, the villagers felt it was too inconvenient to barter all the time, so the whole village held a meeting to discuss how to solve this problem. It is suggested that, as a general equivalent, the corresponding relationship between other items and gold should be compiled into a table, such as one gram of gold corresponds to a sheep, one gram of gold corresponds to a bag of flour and so on. At this time, Lao Zhang no longer has to carry a bag of flour and pant to Lao Li's house to exchange sheep. He just needs to get a gram of gold from his home, You can go to Lao Li's house and bring back a sheep. Lao Li can exchange this gram of gold for a bag of flour from anyone who is willing to sell flour. Of course, he can also exchange it for anything equivalent to a gram of gold
at this time, bitcun entered the era of physical currency
symbolic currency
the good times are not long. After a period of time, the disadvantages of physical currency also appear. Because there are not many gold mines near bit village, it takes too much time and effort to mine and smelt gold. With the use of gold, it will be worn, lost or deliberately hoarded. Once again, the whole village sat together and began to discuss countermeasures. At this time, someone said that in fact, we don't have to really use gold. Just find a piece of paper and write "one gram of gold". As long as the whole village agrees that this piece of paper is equal to one gram of gold, the problem will be solved. Others agree, but at the same time, there are new problems: the real gold needs to be mined and smelted, and the gold mine is limited, so mining and smelting also need costs, so no one can make a lot of gold out of thin air in a short time, but writing is different. As long as I have enough paper and pen, I can write as much as I like, then it becomes who has more paper, Maybe ten thousand pieces of paper can be exchanged for a sheep (in fact, there will be inflation in Economics)
I think so. However, at this time, someone proposed a solution: This paper is not effective for everyone. We only know the words written by the respected old village head in the village, and everyone knows the words of the old village head. The old village head wrote some paper and gave everyone the same amount of paper according to the gold stock of each family. For example, when Lao Zhang's family had two hundred grams of gold, the old village head gave Lao Zhang 200 pieces of paper with "one gram of gold" written on it, and took Lao Zhang's gold as collateral. In this way, the old village head collected all the gold in the village into his own home, and gave the equivalent amount of paper with words according to the amount of gold handed in by each family. At this time, the villagers can trade with the paper as gold, and everyone can recognize the words of the old village head, and others can't forge them. In addition, if someone's paper is worn too seriously, he can get it to the old village head to exchange for the new equivalent paper. In addition, the old village head promises that if anyone wants to exchange for gold, he will return the equivalent gold to that person as long as he takes the paper back. Because the amount of gold in the paper written by the old village head is the same as that in the real home, so as long as the principle of destroying as many paper as new paper is strictly followed, every effective paper can always be exchanged for the corresponding real gold
at this time, bitcun entered the era of symbolic currency (paper money). The old village head took on the role of the government and the bank<

virtual currency of the central system
a few years later, the old village head has to check a large number of old banknotes every day, write new banknotes, and record various accounts carefully. One comes and two goes. The old village head is overworked and unfortunately drives to the West
bitcun held another plenary meeting to discuss what to do. At this time, er Gouzi, the son of the old village head, volunteered to take over his father's pen and assume the responsibility of currency issuance. The young village head Er Gouzi was very clever. He did it for a few days and found that he didn't really need to write so much paper. It can be done like this: Villagers hand in all the banknotes and destroy them, but Er Gouzi will record the amount of banknotes handed in by each household. If you want to pay later, for example, if Lao Zhang wants to exchange a gram of gold for Lao Li for a sheep, you should call Er Gouzi together to explain that you want to put a gram of gold in Lao Zhang's name under Lao Li's name. Er Gouzi takes out the account book to see if Lao Zhang has a gram of gold in his name. If so, you can subtract one gram from Lao Zhang's name and add one gram to Lao Li's name. In this way, the payment is completed, At this time, Lao Li heard Er Gouzi confirm that the transfer was completed on the phone, so he could rest assured that Lao Zhang would lead the sheep away
at this time, bitcun entered the era of central system virtual currency. Every villager doesn't need to pay in kind. The payment process becomes the change of the number in the account book maintained by Er Gouzi<

distributed virtual currency
the new two dogs are smart, but sometimes they are smart but they are mistaken for smart. One day, er Gouzi was staring at the account book, thinking that how much money each household in the village has is what I say, then I'm not. So his mind a hot, privately from the old Zhang's account to draw ten grams of gold to his name
I thought it would be perfect, but I didn't expect that Lao Zhang also had the habit of keeping accounts. One day, when he was about to pay, er Gouzi told him that his account was out of money. Lao Zhang checked his account book. It was clear that there were still ten grams left, so he took the account book to find Er Gouzi. This check found the transfer without Lao Zhang's consent
east window incident! Bit village is boiling. The impeachment of Er Gouzi is inevitable, but through this incident, we found that the account book is concentrated in one person's hands:
this system completely depends on the personal credit of the account book holder. If this person does not obey the rules and tampers with the account book at will, then the whole monetary system will collapse
if this family is on fire or the account book is stolen, It will also bring a devastating blow to the whole system.
just when people are at a loss, an otaku scientist named Nakamoto came to the stage and told everyone that he has designed a virtual currency system called bitcoin, which does not rely on any central processor, to solve the above problems. Then he spoke slowly about his plan
let's take a look at how Tsung Nakamoto designed this system<
infrastructure construction
account book disclosure mechanism
Nakamoto first explained that the existing account book should be transformed as follows:
the account book will no longer record the balance of each villager, but only record each transaction. That is to record the payer, payee and payment amount of each transaction. As long as the initial state of the account book is determined, each transaction record is reliable and chronological, how much money each person currently holds can be calculated
the account book is changed from private to public, so that any villager can obtain the current complete account book as long as they need it. The account book records all the transaction records from the creation of the account book to the current
as soon as this remark is made, it will be fried immediately. The first one doesn't matter, but the second one is simply unacceptable, because the account book records all the villagers' transactions, so that everyone's privacy is not completely exposed
Nakamoto is in no hurry and takes out a pair of strange things
identity and signature mechanism (public key encryption system)
Mr. Nakamoto said, don't panic. Under his system, no one trades with his real identity, but with a unique code name
he showed the magic things in his hand and said that these two things were called secret seal and seal scanner respectively. Later, he will give each household in the village a secret seal and a seal scanner. The functions of the two are as follows:
the secret seal can be stamped with a seal on the paper. The seal of each seal implies a unique string of characters in the whole village, but it can't be seen by the naked eye. We can't make the corresponding seal through observation
the seal scanner can scan a sealed seal, read out the hidden information, and display a string of characters on the LCD screen
with these two magical things, you can trade without revealing your real identity, and the string of characters implied in the seal is the code of the family. How to use secret seal and seal scanner to trade will be described in detail below<
establish a virtual miner Organization (Mining Group)
next, Nakamoto Tsung recruits virtual miners for the whole village. The recruitment requirements are as follows:
miners are divided into groups, one group can be a single family, or several families can be combined into a group
becoming a miner does not affect the normal use of currency
miners spend a certain amount of time every day engaged in bitcoin "mining" activities, However, unlike gold mining, virtual miners can complete their work at home without taking tools to do field work.
miners have a certain possibility of getting paid. The more efforts they make in mining activities, the more likely they are to get paid.
miners can quit at any time, or new miners can join in at any time.
soon, About a fifth of the villagers join bitcoin miners and are divided into seven groups
set up the initial account book (Genesis block)
next, Nakamoto announced that according to the account book in ergouzi's hand, all the gold mortgaged will be returned to each villager according to the balance recorded in the account book, and then the account book will be completely destroyed
then, Nakamoto takes out a new account book and records some transaction records on the first page of the account book. In particular, the payer column of these records is "system", while the payee is the hidden character corresponding to each seal, representing the initial time. The system allocates a certain number of bitcoins to each household by default, but the number is very small, only a few, Even some unfortunate villagers didn't get bitcoin
then Mr. Nakamoto said that since there are very few bitcoins on the market, you can go back to the era of using gold as currency. Since I'm not the village head, I don't have the right to force you to recognize bitcoin. You can decide whether to accept bitcoin or not. However, with the flow of bitcoin and the activities of miners, bitcoin will graally increase
payment and transaction