Virtual currency rating
this is also a distributed (decentralized) digital currency. Unlike the sha256 mining algorithm used by bitcoin, LTC adopts scrypt algorithm. Scrypt algorithm uses sha256 as its subroutine, and scrypt itself needs a lot of memory. Each hash is used as the seed of the input, and then it needs a lot of memory to store another pseudo-random sequence to generate the pseudo-random points of the sequence and output the hash value. In the mining of BTC (bitcoin), it is not enough to rely on simple graphics card mining (it takes about ten to dozens of days to dig a BTC with general configuration graphics card). The emergence of various expensive mining machines has raised the threshold for ordinary people to get BTC through mining, while LTC has certain advantages in using PC graphics card mining This passage comes from Zhihu.)
compared with BTC, litecain has made a little improvement in technology. If BTC is gold now, LTC is silver for the time being
the biggest advantage of litecoin is that it can confirm the authenticity faster. The virtual currency is designed and maintained by Charles Lee. Bitcoin transactions need to be verified, and the average verification time is more than 10 minutes. Most transaction websites need 1 hour to verify. The average transaction confirmation time of liteoin is 2.5 minutes. Developers claim that shortening the verification time increases the practicability of virtual currency. The bitcoin mining efficiency of customized machine and AMD GPU is the highest, making it almost unprofitable for miners using CPU mining. Litecain's mining excludes GPUs and custom processors, so it doesn't rely too much on a small number of professional miners
ppcoin
ppcoin (PPC) was released on August 19, 2012, which has improved the original technology of BTC. Use proof of make and add the concept of coin age
ppcoin is a bifurcated project of bitcoin, which aims to achieve energy efficiency and maintain the best performance of the original bitcoin as far as possible. The unit price of ppcoin is US $0.22 and the total currency value is US $4 million
ppcoin does not have a fixed upper limit of money supply, but it does not mean that ppcoin has obvious inflation compared with bitcoin. Bitcoin can be compared to gold. The annual inflation rate of gold is about 1-3%. Although gold has no known upper limit of money supply, we still know that it is a reliable scarce commodity
ppcoin has two types of casting: work certificate and equity certificate. The coinage rate of working proof is affected by Moore's law, which depends on the doubling of our working proof ability. What we all know is that Moore's law will eventually come to an end. By then, the ppcoin of inflation may be close to the gold level. The annual maximum inflation rate of certificate of equity is 1%. At the same time, ppcoin's transaction costs were destroyed to fight inflation. So on the whole, the coin design of ppcoin is still a very low inflation design in the future, which can be comparable with bitcoin<
ppcoin's reward is similar to lottery, which will determine the winning probability according to the number of ppcoin held by miners. Sunny king, one of the founders, said that their design is based on a new concept of long-term energy efficiency
terracoin
terracoin (TRC) was released on October 26, 2012, with a total currency of 42 million. The speed of each block is 2 minutes, slightly faster than LTC. There is not much special in technology, similar to the proction of BTC halved every four years
however, the operation team seems to have a strong business background and may be better than other bitcoins in circulation. The development of virtual currency is getting more and more attention. Now some teams with business background will accelerate the development of virtual currency
namecoin
namecoin is a distributed domain name system based on bitcoin technology. Its principle is the same as bitcoin. The first release date of this open source software is April 18, 2011
namecoin is generated from an original block which is different from bitcoin's main trading block. It uses a new blockchain, which is independent of bitcoin's blockchain. Because it is based on bitcoin, the security, distribution, robustness, encryption and migration of domain names are guaranteed mathematically. You can dig bitcoin and namecoin at the same time
this project was discussed and proposed by bitdns, which is mainly dissatisfied with the defects of DNS. The only top-level domain name of namecoin is. Bit. It costs namecoin to register a. Bit domain name
in addition, Q currency, Shanda currency, starting point currency and various online game currencies are also virtual currencies.
Weiss ratings, an asset rating agency, has released the world's first rating report on 74 virtual currencies, according to finance magnates. Among them, Ethernet is the highest rated and bitcoin is in the mid stream
The rating criteria of 
Weiss ratings include risk, reward, technology and social acceptance, which are used to compare computer models and get the final results. Weiss ratings also said in a statement on Wednesday that its website had been attacked by hackers from South Korea in an attempt to block the release of the rating report
According to Martin D. Weiss, founder of Weiss ratings, the price trend of many virtual currencies is relatively low, and there is a risk that they will come to nothing. At present, the virtual money market is still relatively complex. The market value of global virtual money is more than half a trillion US dollars, but it is not regulated. On the technical level, blockchain technology also makes it difficult for regulators to legislate in the traditional way of assetsevery coin should be inspected by every appraiser once, and then each appraiser will classify each coin into a systematic level. The currency rating standard adopted by NGC is widely accepted by the coin instry all over the world. The following table is the description of currency rating:
prefix
numerical grade
descriptive description
MS
60 – 70
Mint State (uncoirculated) is not in circulation
Au
50, 53, 55, 58
about uncontrolled is between non circulation and circulation
XF
40, 45
extremely fine
VF
20, 25, 30, 35
very fine
F
12, 15
fine
VG
8, 10
very good
G
4, 6
good
Ag
3
about good
FA
2
fair general
PR
1
poor
NGC will be responsible for the surface condition (phase) problems (defects) The coins will be packaged with "details grading" rating. The coins will be packaged in a purple holder. The label will indicate the description of the surface condition and the grade corresponding to the wear degree of the coins, Some of the descriptions are explained in Chinese as follows:
Artificial oxidation
chopmarks stamp
corrosion
environmental damage
improper cleaning
rim damage
scratches
stained
surface hairlines scratches
whi Some coins can not be digitally rated or packaged, for example, coins that have been seriously damaged or badly cleaned will not be certified by NGC, and then they will be returned to the applicant in a plastic box with the reasons for refusing to package. NGC's experienced experts can accurately screen coins that cannot be certified, Some of the descriptions in Chinese are explained as follows:
authenticity unverifiable can't identify
non eligible types
not genuine (counterfeit currency)
PVC
questionable authen
NGC will carry out "details grading" rating package for coins with surface condition (appearance) problems (defects), The coins will be enclosed in a purple holder with a description of the surface condition and a rating corresponding to the degree of wear, Some of the descriptions are explained in Chinese as follows:
Artificial oxidation
chopmarks stamp
corrosion
environmental damage
improper cleaning
rim damage
scratches
stained
surface hairlines scratches
whi Some coins can not be digitally rated or packaged, for example, coins that have been seriously damaged or badly cleaned will not be certified by NGC, and then they will be returned to the applicant in a plastic box with the reasons for refusing to package. NGC's experienced experts can accurately screen coins that cannot be certified, Some of the descriptions in Chinese are explained as follows:
authenticity unverifiable can't identify
non eligible types
not genuine (counterfeit currency)
PVC
questionable authen
NGC will carry out "details grading" rating package for coins with surface condition (appearance) problems (defects), The coins will be enclosed in a purple holder with a description of the surface condition and a rating corresponding to the degree of wear, Some of the descriptions are explained in Chinese as follows:
Artificial oxidation
chopmarks stamp
corrosion
environmental damage
improper cleaning
rim damage
scratches
stained
surface hairlines scratches
whi Some coins can not be digitally rated or packaged, for example, coins that have been seriously damaged or badly cleaned will not be certified by NGC, and then they will be returned to the applicant in a plastic box with the reasons for refusing to package. NGC's experienced experts can accurately screen the coins that cannot be authenticated. Some of the descriptions are explained in Chinese as follows:
authenticity unverifiable
non eligible types
not genuine (counterfeit)
PVC
questionable
Coin rating is the process of determining the degree of old and new of a coin, which is a rather subjective process. Traditionally, people often use vague words such as "good" and "good" to describe the appearance of a coin
because the old and new degree of coins has a great influence on the value of currency, the simple lack of standardized description of coins is obviously not concive to the market transaction of collected coins. After long-term development, people have graally established a set of relatively objective and standardized coin rating standards, which originated in the United States and has been widely promoted all over the world
extended materials:
collection value:
I. China's first series of rated banknotes. China's first full set of RMB rated banknotes
since 1948, the people's Bank of China issued the first set of RMB, so far it has issued five sets of RMB. The fourth set of graded banknotes is the first series of graded banknotes since the founding of new China. There are nine denominations ranging from 10 cents to 100 yuan
At the same time, the fourth set of RMB rated banknotes is the only collection of banknotes issued in the form of rating, which is the most authoritative and influential variety of banknotes at present, and has extraordinary significance in the history of Chinese currency issuance Second, to commemorate the 30th anniversary of the circulation of the fourth set of RMBit has been 30 years since the fourth set of RMB came out. With the improvement of people's living standards, the use of small banknotes has decreased, and the loss rate is higher. However, e to the accelerated use of large banknotes, the wear and tear is serious, and new banknotes or banknotes with good quality are rare
and the fourth set of RMB rated banknote collection conforms to the current situation and solves the huge market demand of less genuine and better procts. The people's Bank of China specially issues the fourth set of RMB rated banknote collection to commemorate the 30th anniversary of RMB circulation
This is Pingyang square foot cloth in the pre Qin period
"square foot cloth" means that the trousers of "cloth coin" are straight and square, so it is called "square foot cloth", and the opposite is "sharp foot cloth"
the appearance of Pingyang square foot cloth: flat head, square feet, shoulders flat and slightly shrunken, waist slightly bunched; There is a profile, a vertical line from the front to the crotch; On both sides of the vertical pattern, the right side is "flat" and the left side is "Yang"; There is a vertical grain in the middle of the back and a diagonal grain on both sides
72 means 72 points, belonging to the top grade; 05 means cracked or cracked
According to the research of most scholars, the main casting place of Pingyang square foot cloth is Linfen City, Shanxi Province, which is called Hedong Pingyang in ancient times The proportion of "Pingyang" in square foot cloth was the largest. Pingyang, the most common type of square foot cloth, accounts for more than half of the square foot cloth unearthed several times. Usually, because of the good quality of copper, the unearthed places are mostly found in the north. The climate is dry, most of them are beautiful in rust color and well preserved
extended data:
rating currency is a kind of currency packaged in anti-counterfeiting hard box after being identified by a professional appraisal company and given an objective score for the proct grade
GBCA (China), also known as Gongbo rating, was founded in 2011. It is a professional coin rating company initiated and founded by Duan Honggang (online name: Yang Gongbo), a famous Chinese coin collector the scoring standard of ancient coins of China GBCA (Gongbo) rating company is:
the surface state of ancient coins is based on the beauty of the whole, the beauty of words, the beauty of rust and color or the beauty of handed down. Cooked pit handed down procts, shuikeng procts for the middle. Others are ordinary. All the ancient coins were rated according to three grades:
meipin: corresponding to 75, 78, 80, 82, 85, 88, 90, 92, 95, 98 and 100 points
top grade: corresponding to 55, 58, 60, 62, 65, 68, 70, 72 points
intermediate: corresponding to 25, 35, 45, 50, 53 points
no more points below 25
there was no score for breaking, cracking, repairing and mending, but the corresponding comments were given according to the overall effect
in case of casting defect, cleaning, more attachments, etc., or in case of heavy rust dressing, points shall be given as appropriate
reference materials: square foot cloth network
ms-60: UNC, no wear, many deep scratches or hairlines are allowed, and the identification of casting lines may not be complete
ms-61: UNC +, no wear, multiple deep scratches or hairlines are allowed, and the identification of casting lines may not be complete
ms-62: UNC ＋, no wear, less scratches or hairlines are allowed, and the identification of casting lines may not be complete
ms-63: Bu, no wear, general size scratch or hairline is allowed, and the identification of casting lines may not be complete
ms-64: Bu +, only a few scratches or only one or two more serious scratches or hairlines, and the recognition of casting lines is medium
ms-65: Choice BU, there may be small / unimportant scratches or hairlines, but there are no scratches or hairlines in the focus area, and the recognition of casting lines is above medium
ms-66: Choice BU +, with one or two minor / unimportant scratches or hairlines, but no scratches or hairlines in the focus area, and good identification of casting lines
ms-67: Gem Bu, at first glance, looks like a newly cast one. If you look at it carefully, it may have small / unimportant defects, so it has very good identification of casting lines
ms-68: Gem Bu +. At first glance, it looks like a newly cast one. If you look at it carefully, it may have slight defects, so it has very good identification of casting lines
ms-69: Gem Bu ＋, close to the perfect proct. If you look closely, there may be very small defects, which is close to the perfect casting pattern recognition
ms-70: perfect proct, even when viewed under a 10x magnifying glass, has no trace of contact, and has perfect casting pattern recognition (this rating is rarely found in the three major rating companies NGC, PCGs and ANACS in the United States)
64 is the fraction, followed by RB is the color of the coin, BN is the color of the coin, is coffee copper. RB is the color of the coin, coffee with copper. The color of the RD coin is copper.
A note or coin that has been appraised by a third-party coin appraisal company is called a rating note. It means that the rating company will give the coin a score, which is the rating in the rating. Generally, the one with a higher score will be worth less than the one with the same score. The reason why the price is higher than that of bare money is that the rating costs money, time cost and the risk of losing and damaging the express delivery
the biggest advantage of rating currency over bare currency is that there is no need to worry about the authenticity of the currency (as long as the rating company is reliable) as long as it can enter the shell, the rating company will be responsible for the authenticity of the coin. If the appraisers take the fake procts seriously into the shell, the rating company will be responsible for it and pay the price of the same kind of genuine procts. Secondly, the coins are sealed and sealed, which can relatively eliminate the damage of natural factors such as air and moisture, making the coins easier to keep. Moreover, because the rating coin has a shell outside, it can be taken directly by hand without gloves or tweezers, which is convenient to play
however, there is a misunderstanding that highly rated banknotes must be perfect, which is wrong, such as yellow spots on banknotes, binding marks and stapler pinholes (in the past, central banks in India, Pakistan and other countries used staplers to bind banknotes, counting 20 banknotes and then stapling them together, So it's hard to find bills in some currencies that don't have pinholes. Many rating companies will ignore these flaws. Especially the pursuit of flawless, choose high cents also want to look carefully
moreover, many rating companies are only responsible for the authenticity of banknotes, but they don't specially look at whether it is a change number currency (for example, several 8, several 9). Therefore, the number playing friends also need to look at whether it is a change number currency
for coins, it's better to pass the X-ray machine if conditions permit, because some coins are repaired (especially copper coins). You can't see them by naked eye, only the photo can find the repair.