The latest data from Coin360 shows that since New Year's Day in 2020, the total market value of cryptocurrencies has increased from a minimum of US $ 167.6 billion to a recent maximum of US $ 307.7 billion, an increase of 74%. BCH, ETC, BSV and other popular production-reducing currencies rose by more than 150%, and the currency market has been lively for more than a month, sweeping the haze brought by the "overcast" in the second half of 2019.
With soaring currency prices and miner donation plans, 51% attacked and questioned, BCH is undoubtedly the focus of this capital feast.
Under the spotlight, the "destroy for perfection" and "good reputation" for BCH came one after another. There were "BCH sounded the horn of this round of production reduction" and "BCH is excellent in decentralization". ", And" BCH is still a cold coin in essence "and" destruction "such as" is undergoing a 51% attack ".
- Twitter Picks | Follow BCH? Li Qiwei proposes that miners donate 1% of block rewards to support Litecoin development
- BCH's "time bomb"? The commentary believes that "halving BCH" is a disaster for them.
- Bitcoin ABC will include BCH miner donation plan in May, donation ratio changed to 5%
- It is only 32 days from the halving of BTC. BCH and BSV have completed the halving in succession. Does the reduction in production affect the geometry?
- Double spend attempts on the BCH network are frequent, and about 10% of double spend transactions are confirmed
- Transaction reversal: the two mines attacked Bitcoin cash by 51%
Unprecedented reputation, destruction of perfection. From "Mencius · Lilou Chapter 1 · Sect. 21", Mencius said: "It has the reputation of perfection and the destruction of perfection." It means that there are both unexpected praise and slander that demand perfection.
Then, what kind of value core does the "mainland currency" in people's impressions and the "prince" of "relying on forked BTC stand on" have a market capitalization of USD 7.4 billion? Is the stable development of BCH the pursuit of capital or the power of consensus?
"Change" before BCH cuts
According to the BCH code setting, when the block height reaches 630,000, the mining reward will change from the current 12.5BCH / block to 6.25BCH / block, and the annual BCH inflation rate will also change from the current 3.97% to 1.80%.
The latest data from 1bch.com shows that it is expected that the BCH production reduction time will be April 8 and the countdown will be 50 days.
The immediate result of the reduction in production and the reduction in inflation caused by production reductions is the rise in currency prices.
The price of BCH rose from a low of around 190 at the beginning of January 2020 to 490 USD in mid-February 2020. It has increased by more than 150% in less than a month, which has also driven mainstream currencies such as B S V, BTC, LTC, and ETH. The price of species is rising. BCH is reputed to be the first to “sound the clarion call for production cuts” to reduce production coins.
At the same time that the currency price has risen, the mining computing power of the BCH network has also increased significantly.
BCH network computing power trend since 2019
BCH network computing power trend since 2019
Bitinfocharts real-time data shows that the BCH network computing power has also increased from a minimum of 2.33Eh / s more than a month ago to the recent 5.00Eh / s. With the BCH price increasing by 150%, the network computing power has increased by 114%. During the same period, the computing power of the BTC network has not increased significantly, and has fluctuated around 110Eh / s in the past month.
For BCH, for such a currency with a computing power of only 5% of BTC, each increase in computing power means that its own security and stability will increase.
In the case of a small increase in the overall computing power of the SHA256 network, the BCH price has increased significantly, which can be said to have saved some miners.
"My S9 miner was basically retired years ago."
The miner Yule is a Bitcoin miner. Some of his S9 miners have been used for more than two years. Even after the "AsicBoost" is turned on, his life is short. At this moment, BTC, BCH, and BSV are three SHA256 currencies. The price started to skyrocket, which saved his mine.
According to AsicBoost official website data, using AsicBoost technology can reduce power consumption by 10% -20%. 
"Under the background that the hash rate of the entire SHA256 network has not increased significantly, the currency price has increased a lot, which is a good thing." Yu Le told OKEx Intelligence Bureau. "The reason for the analysis is the sudden domestic epidemic situation, which has caused many miners to fail. Miners cannot be put on shelves for delivery. "
According to the observation of the OKEx Intelligence Bureau, the computing power of the three networks, BTC, BCH, and BSV, has indeed remained at 120Eh / s since the Lunar New Year. This has given those "minor dying" generations of mining machines a chance to breathe.
"This is also an indirect benefit of the market driven by BCH production cuts." Yu Le said.
Of course, Bitcoin Cash (BCH) as a bitcoin's competitor has also been questioned, and BCH network security is the first to bear the brunt.
BCH cuts production, does not incur 51% attack
After BCH cuts the rewards, will the BCH network be safe?
In fact, as early as October 2019, at the "2019 Global Digital Mining Summit" held in Frankfurt, Wu Jihan accepted an interview with bitcoin.com CEO Stefan Rust when asked about his During the impact, Wu Jihan gave an objective explanation of his view on the impact of reduced production on network security.
"BCH is much earlier than Bitcoin's production reduction, which means that at some point in the future, the computing power of the BCH network will suddenly decrease production, but I don't think this (BCH network) is safe." Wu Jihan said.
Wu Jihan also believes that the 51% attack is not particularly worth panic.
Wu Jihan said: "Because there are some people who monitor the network (technical personnel responsible for risk control), hackers face not only the known computing power on the network, but also the unknown computing power (it is difficult to control the entire network) ), So I do n’t think this is a problem that deserves special attention. There has been a 51% attack on PoW, but people are less and less worried about this problem these years. Even if a 51% attack occurs, it is not The end of cryptocurrencies, because people will always find a solution. "
"Don't worry about 51% attacks" is Wu Jihan's attitude, and Liu Changyong also holds the same view.
"The impact on security is not great. Some people say that the reduction in BCH production will lead to a 51% attack. This is hostile." Liu Changyong told the OKEx Intelligence Bureau.
Liu Changyong (hereinafter referred to as Teacher Chang Yong) is the founder of Zhimi University, the director of the Blockchain Economics Research Center of Chongqing Technology and Business University, a PhD in economics from Peking University, and an important supporter of the BCH ecology. When the question will be affected, teacher Chang Yong said.
Teacher Chang Yong is popularizing blockchain knowledge for students
"The currency of POW is relatively safe as long as the computing power reaches a certain scale. BCH has added restructuring protection (10 block confirmations), and its ability to resist 51% attacks is stronger and more secure."
As for why BCH is safe after the cut, Chang Yong gave his own explanation.
"Now the price of BCH is around 3300 yuan. After the reduction of production, the security of computing power will also be equivalent to the price of 1650 yuan. In November 2018, when the price of BCH was around 600, it faced the true 51% computing power of the CSW team. There is no problem with the attack threat, let alone now. In addition, in November 2018, BCH added a restructuring protection mechanism in response to the CSW attack threat. The exchange only needs to set 10 confirmations to prevent 51% attacks. Therefore, More secure than BTC and BSV. "
"In general, the reduction in production has little effect, and there is no need to worry about the impact on safety," said Chang Yong.
What is the impact on miners in the BCH network after BCH cuts?
"The impact of BCH production cuts on miners 'earnings is also limited. Since BCH accounts for a small proportion of the entire SHA256 algorithm coin, the impact of BCH cuts on miners' earnings is not significant, which is roughly equivalent to the 2% drop in BTC prices."
"What really affects the market is the reduction in BTC production, which may lead to short-term mining disasters," Chang Yong told OKEx Intelligence.
What are the differences between BTC, BCH, and BSV as the three giants of reduced production coins in 2020?
Line disputes-irreconcilable contradictions
Speaking of the differences between the three giants that reduce production in 2020, the "route dispute" of BTC, BCH, and BSV is the biggest difference.
"The direction of BCH is a decentralized cryptocurrency. (32M large block route) I think it is the most likely among mainstream currencies to achieve Satoshi Nakamoto's original intention." Teacher Chang Yong said.
Regarding BSV's return to the BTC 0.1 version of the course, Chang Yong believes that its competitiveness mainly comes from three aspects.
"The first is the financial support of the casino owner CA. These external funds are very scarce and effective in a bear market;"
The second is organized professional operation. CA and Jimmy have extensive experience in financial, political and public opinion operations and have systematically operated BSV; "
The third is to use CSW to establish the banner of returning to classics. In the immature cryptocurrency community, a group of people who admired Satoshi Nakamoto, were dissatisfied with the status quo, and were anxious to succeed. "
But gaining these advantages comes at a huge price.
"These advantages of BSV seem to be very powerful, but the price is a high degree of centralization. This is an advantage in company management, but it is indeed a great disadvantage in cryptocurrencies with decentralization as their responsibility. And if we want to be centralized BSV cannot compete with the cryptocurrency of fiat currencies at all. "
When asked about the ferocious rise of BSV years ago, and the market value once surpassed BCH, Mr. Chang Yong said: "BCH can adhere to the direction of decentralized cryptocurrencies, and does not need to care about what BSV does and how much it costs."
So, what is the difference between BCH and BTC?
"BCH mainly insisted on the direction of making free world currency, and BTC turned to stored value digital gold." Chang Yong said.
From a development perspective, BTC and BCH have also chosen two different routes.
Part of the BCH development team
"The development of BCH has been more decentralized than BTC from the beginning. The reason is that BCH was originally born because it opposed Core's dominance of Bitcoin's direction. There are several teams trying to get rid of Core's control and develop an expanded version for BTC. .Although they all failed, when the expansion failed and BCH was born, most of these teams went into the development of BCH. Therefore, the development of BCH has always involved multiple teams, ranging from 5-8 in different periods. "
Even the Bitcoin ABC team that first developed the 8M BCH version has far less influence than Core's influence in BTC. In terms of community influence, it is affected by other development teams, large enterprises, and important figures like Roger, Wu Jihan Checks and balances. Therefore, the degree of decentralization of BCH is much higher than that of BTC. "
According to Chang Yong, BCH, the star of this year's production reduction, is moving along the direction of Satoshi Nakamoto's understanding of cryptocurrencies.
Before any new thing becomes deterministic, it will face a mixed reputation situation, and BCH is no exception, especially when the BCH production reduction is imminent and the community is fiercely discussing it.
On the way to reducing production, both "destruction" and "reputation" make BCH stronger
"The essence of BCH is to avoid cold coins, mainland currencies." Such a recognition has almost become a small-scale consensus in the currency circle. So, is BCH taking over?
"The misunderstanding that BCH is a cold coin, ore bullion coin, and even Chinacoin stems from the battle for expansion. Opponents of expansion, mainly core proponents, attack BCH by creating this misunderstanding, and this attack continues to this day. In 2018 CSW supporters also used this to attack BCH during the year's computing war, regardless of being highly centralized, "the teacher told OKEx Intelligence.
If it is said that the attack on the name is just a matter of "no pain and no itch", then the "unknown computing power" incident that happened more than a month ago may be "damaging the muscles and bones".
In December 2019, a large amount of unknown computing power appeared on the BCH network, which almost exceeded 51%. Therefore, there are voices on the Internet that BCH is facing a "51% attack".
Currently unknown computing power accounts for 23.5%, and at the end of December 2019 this number exceeded 51%
Teacher Chang Yong gave his own observations on the incident.
"The BCH community has been paying attention to this incident for a while. At least a large part of the unknown hash power has been proven to come from tokens. They have indeed opened the function of switching hash power between BTC and BCH, also known as the 'machine gun pool'. The main reason for the existence of the machine gun pool is that the difficulty adjustment of BTC and BCH cannot keep up with the changes in relative prices, so switching mining will have a certain profit margin. Profit is the rule of the market economy, so the "machine gun pool" itself need not be condemned . "
In order to solve the problem of the machine gun pool, BCH modified the difficulty algorithm as early as November 2017, changing the difficulty adjustment cycle from 2 weeks to 10 minutes (that is, each block is called DAA), so that the difficulty adjustment can keep up with the computing power faster. Fluctuations, which guarantees their survival. BSV also survives on DAA, although they think it is wrong.
However, in the view of Teacher Chang Yong, this is still not enough. The 10-minute difficulty adjustment cycle still gives the machine gun pool a chance.
"BCH's 10-minute difficulty adjustment time is still relatively long, which gives the machine gun pool a profitable space for computing power. Although there is no fatal effect, it will lead to fluctuations in block production time. In this regard, I think shortening the block time to 1 minute It can shorten the profit window of the machine gun pool and reduce the harm of the machine gun pool. However, this modification involves the underlying consensus and is difficult to reach. "Teacher Chang Yong said.
In any case, the so-called 51% attack threat has allowed the BCH network to evolve the DDA mechanism. These threats have allowed BCH to evolve a more powerful defense system.
The "destruction" and "reputation" of BCH have not ended, nor will they end. As investors and observers in the crypto field, what you and I need to do is to ensure that we do not get out.
In the first half of 2019, Bitcoin's gains outpaced those of its competitors. Many people take this as a basis and believe that it was correct not to expand the capacity that year. Bitcoin should not be used for payment, but for value storage and digital gold. This recognition has seriously impacted the original intention of Bitcoin, and endangered the consensus on decentralized cryptocurrencies.
As a result, Chang Yong's more than 20,000-word long article "The Beginning and End of the Bitcoin Expansion" was born, spanning more than 4 years, and truly restored the details of the BTC fork and later the BCH fork. 
 What technology is AsicBoost? Let the mine ring explode;
 Wu Jihan talked with Bitcoin.com CEO about mining and industry growth;
 Liu Changyong: The beginning and end of the battle for Bitcoin expansion;