Put to death: Full record of BCHA offensive and defensive battles. Who is chasing them in a bloody way?

The author is Mr. Liu Changyong, who has exclusively authorized WuShuo Blockchain to publish the text. The full text has 7,619 words.

BCHA is under continuous computing power attacks by suspected BCHN supporters, mainly in the form of empty block attacks. Both the attacker and the defender have made multiple stages of strategic adjustments.

Regardless of the outcome of the attack, this BCHA offensive and defensive battle provides a good example for us to understand PoW and the problems in the development of decentralized cryptocurrency, which is worthy of study and reflection.

1. Three BCH forks

On November 15, 2020, BCH forked again. This is the third fork after the BCH birth fork on August 1, 2017 and the BSV fork on November 15, 2018.

The reason why BCH forked is that the decentralized crypto-economy will have different exploration directions in its evolution, just like the evolution of organisms. However, BCH forks more frequently because decentralized cryptocurrencies have not yet formed an effective governance mechanism, and BCH is more decentralized, with a diversified development team and opinion leaders, making it easier to fork due to major differences.

Other public chains either have strong ecological centers, such as ETH, TRX and other public chains; or they have moved from decentralization to centralization, such as BTC forming the Core center and BSV centered on the CSW team; or they simply have no development community, and thus no forks, such as Dogecoin, LTC, etc.

In 2017, BCH forked from BTC due to a dispute over capacity expansion (see https://www.8btc.com/article/450758), and in 2018, BSV forked due to the failed organized power grab by the CSW team (see https://www.8btc.com/article/287572). Both times experienced long-lasting and fierce wars, and the hostility and attacks even continue to this day.

In comparison, the cause of the BCH fork was somewhat unexpected, the war was relatively mild, and the impact was relatively small. However, the fork practiced and demonstrated the inherent logic of the decentralized crypto-economic ecosystem, which is still very valuable.

2. Reasons for BCHA fork

The root cause of the BCHA fork is the lack of an effective decentralized governance mechanism. The direct reason is that BCH's original core development team ABC, regardless of community differences, used code management rights to arbitrarily write the IFP (8% of new coins per block are paid to addresses controlled by ABC) code into the upgrade node program and announced the upgrade on November 15.

The problem behind this is that BCH, which does not have a mature governance mechanism, has actually given the ABC team greater power. ABC is not good at governance and politics, and after three years of leading development, it has become arrogant and no longer pays attention to the opinions of other developers, related companies and other influential members, and even complains a lot.

At the same time, after three years of bear market, ABC is under great financial pressure, and the opportunity cost of focusing on BCH development and maintenance is high. Due to some complaints and frictions, the relationship between ABC and donors has also deteriorated, and the donated funds have decreased.

ABC originally had high support in the ecosystem. Opponents of IFP have also been trying to resolve the crisis through communication and avoid division. Some supporters of IFP also advocate the implementation of IFP on the premise of reaching consensus. However, ABC’s political experience and ability are seriously insufficient, and it naively took the wrong step of forcing IFP. It not only broke with IFP opponents, but also caused some IFP supporters to firmly oppose ABC and turn to support BCHN, including Jiang Zhuoer and myself.

It can be said that ABC’s naive behavior directly led to the BCHA fork. When ABC wrote the immature IFP into the code and announced the upgrade on November 15, the fork became irreversible. This is because, for most people, this IFP version is unacceptable, and it is difficult to withdraw the announcement once it is released.

3. Harmonious fork suggestions

Realizing that the fork is inevitable, on August 27, I sent the "Suggestion for the Rational and Harmonious Fork of BCH" to the community. (https://read.cash/@ProfLiu/the-suggestion-for-the-rational-and-harmonious-fork-of-bch-cca9fb96)

I think that since the fork is inevitable, we should try to make the fork peaceful, determine the details of the fork as early as possible, and reduce uncertainty and mutual attack consumption. The fork of the decentralized ecosystem is inevitable, and it is more important to establish a harmonious fork mechanism through this fork for the orderly evolution in the future. This is the same as the significance of a peaceful presidential election instead of a bloody regime change.

I suggest that BCHN and ABC put aside the most acute issue of the naming rights dispute, reach a consensus on a harmonious fork, and sit down to talk. In the negotiation, focus on resolving the naming rights issue. Once the naming rights issue is resolved, other issues will be easily resolved, and ecological stability and protection of user rights and interests can also be achieved.

This suggestion was agreed by some important members of the ecosystem, but the key warring parties, BCHN and ABC, firmly opposed it. They both believed that the other party was a bad guy and should be driven out of the community. Both sides were firm in their beliefs and could not be shaken.

A harmonious fork is impossible to achieve, but the key to reducing uncertainty, intensity of struggle, and damage to the BCH ecosystem is to determine the naming rights as early as possible.

For this reason, I suggested to Yang Haipo that we launch BCHN and BCHA futures trading, and clearly name the one with a higher price before the fork as "BCH". At the end of September, Coinex launched two futures trading pairs and announced the strategy of naming the one with the highest price as BCH. At that time, the BCHA/BCHN price ratio was roughly 0.17.

As the transaction unfolded and other exchanges followed suit, the situation became clearer, with BCHA/BCHN falling from 0.17 to 0.05. The naming dispute was basically settled. In early November, the ABC team announced the release of a version supporting BCHN, and was willing to hand over the management rights of the BCH official website bitcoincash.org, and identify the ABC chain as BCHA. The naming dispute was over before the fork.

At this point, the suspense left is whether BCHA can survive the fork.

4. The Birth of BCHA

On November 15, at the height of block 661648, the fork moment came. The price of BCHN was high, and the supporting computing power was also large. The block was successfully produced 3 minutes after block 661647. However, the price of BCHA was only about one-tenth of that, and the difficulty of the two chains was the same at the time of the fork. Therefore, mining BCHA meant a loss of 90%.

If no one bears the loss to mine the first few dozen blocks, the difficulty will never be adjusted down, the BCHA chain will not be able to produce blocks, and will die.

One hour and 40 minutes later, BCHA block 661648 was finally born. The miner left a message on coinbase: "Very good mining pool /ABC/". It seems that the foreign miners are thanking the Chinese mining pool. Yang Haipo's Viabtc mining pool has announced support for BCHA mining, and the thank you may be for him.

It took BCHA about 6 days to return to the normal block time. The 100 blocks from 661647 to 661747 normally only took 17 hours, but BCHA took more than 5 days.

This founding miner mined the 22 most difficult and loss-making blocks from 661648 to 661670, which was a considerable expense. Starting from block 661671, the anonymous founding miner stopped mining, and the miner marked as "/ViaBTC/Mined by bucher/" on coinbase continued to mine blocks.

5. Peaceful development proposals

From the beginning of August to November 20, due to the uncertainty and community friction caused by the fork, the price of BCH continued to fall, breaking new lows against the price of BTC. It fell from the lowest of 0.0282 on August 2 to 0.0135 on November 18, a drop of half.

As BCHA moves towards normal block production, the fork seems to have been settled, eliminating mutual interference. Both parties should devote themselves to their respective construction as soon as possible.

To this end, I published "Suggestions after the BCH fork" (https://read.cash/@ProfLiu/suggestions-after-the-fork-of-bch-bch-a2a853a6) on November 19, which mainly includes:

1) It is suggested that both sides stop hostility and develop independently.

2) After BCH completes some consensus-building matters in the next upgrade, the hard fork time will be changed from the original six months to three years to maintain ecological stability.

3) BCHA has a small market value and can maintain a hard fork upgrade every six months and experiment with improvements such as governance mechanisms.

4) BCH introduced improvements based on the successful BCHA experiment in a hard fork upgrade three years later.

This suggestion was not responded to by either side. In fact, an attack was brewing.

6. Empty block attack and dust attack

Just as BCHA's block generation was becoming stable, the attack on BCHA began on November 20. At 22:45, the attacker mined 661684, an empty block with only new coin issuance transactions and no other transactions. At the same time, the attacker sent a large number of junk transactions of around 0.002 to fill up the memory pool.

The reason why the attacker did not use the common 51% attack of POW to reorganize the BCHA chain is that BCH adopted a reorganization protection strategy in the BSV defense war, and the reorganization of more than 10 blocks will not be accepted by the node. In this way, as long as the exchange requires more than 10 confirmations, the double-spending attack will not succeed. At that time, the 51% attack threat from CA and CSW was directly repelled.

The attacker uses empty block attack + dust attack to continuously produce empty blocks, so that normal transactions cannot be packaged, thereby destroying the normal transfer function of BCHA. Dust transactions attempt to congest the node memory pool and further hinder normal transfers and block production.

The attacker left a message on coinbase "Nov 25th 2020/", and later changed it to "Nov 25th 2020: bcha dump | voluntarism.dev", which seemed to be based on a voluntarism stance and threatened the market to sell a large amount of BCHA on the 25th.

After 15 empty blocks were created in a row, the defense began. At 3:31 on the 21st, block 661700 packed 18228 transactions, with a size of 8M and a total mining fee of 0.3BCHA. Coinbase left a message "/ViaBTC/Mined by goatpharmer/".

7. Suggestions for stopping the attack

From the 20th to the 24th, the attackers and defenders were in a stalemate. The attackers produced most of the blocks, and the defenders continued to produce blocks, each block was 8M, and packed nearly 20,000 transactions.

In my opinion, empty block attacks and dust attacks are unprofitable and irrational behaviors, and they are unlikely to succeed. On November 24, I published a proposal on "Stop Attacking BCHA" on read.cash. The main reasons are:

1) The attacking party consumes more energy than the defending party, and the defending party only needs to come up with a block every two hours.

2) Dust attack brings the defender around 20 yuan in transaction fee income for each block.

3) There is no fierce community confrontation like the BSV fork, so there is no need to launch an attack.

4) In the absence of community confrontation, many people are dual wielding, and attacks simply cause losses to everyone and are unpopular.

5) As long as there is computing power to support the block packaging transaction every two hours, BCHA will not be killed and the attack will be futile.

6) It would be better for the ABC team to continue developing BCH than to force them to give up development or turn to the closed BSV development.

7) If BCHA is really killed, it is actually telling Core fans and BSV fans that BCH can be killed in the same way.

After the suggestion was released, at 4:36 on the 25th, starting from block 662116, the empty block attack stopped, and the attacker's 4M block and Viabtc's 8M block together cleaned up the garbage transactions in the memory pool. Some other mining pools, such as ming-dutch, also joined the normal mining.

I once thought that the attacker had regained his rationality. But at 21:23 on the 25th, starting from block 662135, the empty block attack and dust attack started again, and Coinbase left a message "Nov 27th 2020: run the numbers | voluntarism.dev", leaving an identity "voluntarism.dev".

The attacker changed the coinbase to Chinese: "No matter black or white hash, the one that can protect the interests of miners is a good hash." This is a variation of Jiang Zhuoer's cat theory. But this behavior is not in line with Jiang Zhuoer's rational habits. Jiang Zhuoer himself also clearly supports harmonious forks. This coinbase message seems to have some ulterior motives.

8. Orphan Block Attack

An orphan block attack is when an attacker receives a block with normal transaction packaging and immediately uses a large computing power to produce two consecutive empty blocks to isolate the normal block. This is a small reorganization attack or 51% attack, the purpose of which is not to double spend, but to prevent the normal packaging of transactions.

After the attack was recovered, ViaBTC continued to produce blocks normally, and normal transactions could be packaged within three or four hours.

On the 27th, the attacker voluntarism.dev issued an attack threat on Twitter: Anyone who dares to mine BCHA blocks will be isolated unless 100% of the block rewards are given to the ABC fund address. The code was also provided to teach miners how to increase the fund ratio from 8% to 100%.

Weibo blogger Bruce Lee forwarded this threat and believed that facing this kind of orphan block attack threat, it is impossible to have a large computing power loss to protect BCHA. ABC can only change the algorithm or even change the POS.

The orphan block attack occurred on the 28th. After viabtc mined block 662397, voluntarism.dev quickly mined block 662397, 98, and 99, invalidating viabtc's block 97.

However, the defenders were also prepared. Anonymous defensive miners then used their high computing power to produce 12 blocks based on viabtc's 662397, isolating the attacker's 3 blocks again, and more than 10 blocks will not be reorganized. Anonymous defensive miners left a message on coinbase, "/voluntarism.dev, aka asicseer.com and u/ugtarmas, is a bully/", calling the attacker a "bully".

This offensive and defensive battle ended with the failure of the attacker voluntarism.dev. Some people in the BCH community believe that behind voluntarism.dev is the asicseer.com mining pool, whose CEO is Alexander Levin Jr., and his id on reddit is u/ugtarmas.

9. Stand up against it​

After the orphan block attack failed, voluntarism.dev temporarily gave up the orphan block attack because the cost of failure was too high, and continued to use empty block attack and dust attack.

The continuous attacks, especially the orphan block attacks, have aroused the resentment of some people in the mining circle. At the same time, the price of BCHA has remained basically stable. Mining BCHA is still profitable. The number of miners mining BCHA has increased.

From the 28th to the 29th, at least 5 mining pools or independent miners, including anonymous defensive miners, viabtc, and ming-dutch, participated in the defense of BCHA.

Anonymous defense miners only package normal transactions, not dust attack transactions, and the blocks are within 100k. They call voluntarism.dev a "bully" in the coinbase, such as block 662406.

Viabtc mining pool packs 8M blocks, about 20,000 transactions, and different miners produce them. For example, 662453 is produced by miner mminer55.

The Mining-Dutch mining pool packs 2M blocks, such as block 662454.

Bcha.pro mining pool packs blocks within 1M, such as block 662464.

Another anonymous mining pool packs 32M blocks, each of which includes more than 75,000 transactions, with a transaction fee of up to 1.5BCHA, and is the main force in digesting dust transactions, such as block 662450.

At 11:00 a.m. on the 29th, the empty block attack on BCHA stopped, and blocks began to be produced normally at the height of 662447; at 6:00 p.m., at the height of 662462, the dust transactions in the memory pool were cleared.

The offensive and defensive battle came to an end again.

10. The price of “ freedom ”

At 7:57 on November 30, at block height 662589, the empty block attack and dust attack began again. This time the coinbase message was changed to "evoluntarism.dev:6174 x/x | the price of freedom".

This message shows that 1) the attacker wants to kill BCHA; 2) the attacker has paid a significant cost for the continued attack; 3) the motivation for the attack is based on libertarian or anarchist ideas and is opposed to extracting governance funds from block output.

The PoW ecosystem has long had the practice of extracting funds from block output. Dash and ZEC have been running for many years, and no one has launched a computing power attack for this reason. The attacker attacked BCHA, fundamentally because of the hatred generated by ABC's forced promotion of IFP.

So far, the attack has shown obvious irrational characteristics and has become an action based on belief and hatred, more of hatred. This attack itself is to use violence to force consistency and kill the forked chain, which violates the spirit of liberalism.

Under the belief of "the price of freedom", the attacker adjusted the attack strategy again and implemented a "empty block attack + dust attack + orphan block attack" with greater computing power:

1) The attacker first uses high computing power and high-cost empty blocks to attack, maintaining the difficulty at a high level and driving away normal miners. For example, from block 662721 to block 662740, 20 blocks were produced in 34 minutes, and the average interval between blocks was only 1:47 minutes.

2) After the difficulty is raised, stop mining, wait two or three hours, resume high-computing mining, and adjust the difficulty down.

3) If a normal packaged block appears, it is a 51% attack by large computing power, isolating the block. On the afternoon of December 1, 6 Viabtc blocks were isolated.

The attacker is willing to spend all his money, so how should the defender respond?

11. Computing Power vs. Consensus

Under the powerful computing power attack from the attacker, on the evening of December 1, the BCHA block on various browsers stopped at the attacker's block 662658, and no new blocks were produced.

On December 2, ABC urgently released version 0.22.8, set checkpoints, abandoned the attacker's 662687 block and the attacker's empty block, and used defensive computing power to pack a new 662687 block and form a defensive chain based on this block.

However, at this time, BCHA's main browsers such as blockchair.com and viawallet all stopped at the attacker's block 662658. BCHA's exchanges also did not switch to the defense chain. Coinex announced the suspension of deposits and withdrawals. The attacker seemed to be about to succeed.

On December 2, evoluntarism.dev issued a harsh ceasefire condition on Twitter:

1) The sha256 mining algorithm is no longer used.

2) The full name of the coin cannot contain "bitcoin".

3) The coin code cannot contain "bch".

Except for the third point, the first two are extremely excessive. In fact, there are dozens or even hundreds of coins in the market named "bitcoin" and using the sha256 algorithm.

Given that BCH had already been abandoned and the management of the official website had been handed over before the ABC fork, this request was a complete gesture of surrender.

However, no matter the attacker's chain is longer or appears earlier, the attacker is still an attacker. Even if ABC loses the majority of its supporters in the BCH community, it still has its supporters. As long as ABC and its supporters do not give up, for browsers, exchanges, and mining pools, the future of this coin lies in ABC and its supporters, not the attacker.

On the afternoon of December 2, major BCHA browsers such as blockchair and viawallet completed node updates, starting with block 662687 and updating to the defender's chain. As of press time, the attacker's empty blocks have not appeared again.

Many staunch supporters of PoW believe that BCHA does not follow the longest chain rule and is developer-centralized, and mock it as "Prove of Developer". However, as long as there are people to develop and maintain it, there is computing power to support it, there are supporters, and there is infrastructure support such as browsers and exchanges, computing power will hardly kill a decentralized cryptocurrency. Computing power cannot kill consensus.

12. Outlook for Offensive and Defensive Battles

Overall, this offensive and defensive battle is not necessary, because the naming dispute was resolved before the fork, ABC gave up the name of BCH and even handed over the management of the official website. This is completely different from the fierce competition between the two sides during the BSV fork in 2018.

The overall losses in this offensive and defensive battle were not large, which was determined by the nature of the attack.

The BSV fork in 2018 was caused by CSW’s threat to launch a 51% reorganization attack on BCH. Both the defenders and attackers accumulated a large amount of computing power, far exceeding the output income, and the total daily consumption was more than one million yuan. This dealt a heavy blow to the entire market in the cold winter of 2018.

In this offensive and defensive battle, both sides generally maintained normal block generation computing power, and only used a large amount of computing power during the orphan block attack. The price of BCHA did not fall sharply. Therefore, the mining income loss was not large. This is also the reason why the offensive and defensive battle can continue.

The attack and defense mode this time determines that the attacker is at a clear disadvantage in terms of economic benefits. This is a huge difference from the 2018 fork.

In 2018, the defenders had to maintain high mining power and continuous losses in order to protect BCH from 51% reorganization attacks. The attackers did not need to attack all the time, but could launch attacks at any time. It can be said that the defenders were in the open and the attackers were in the dark.

In this attack and defense battle, the reorganization protection eliminated the threat of 51% reorganization attack, and the attacker can only use empty block attack, dust transaction attack and orphan block attack. The situation is reversed, that is, the attacker must continue to pack empty blocks and maintain dust transactions in the memory pool, while the defender only needs to pack a large block every few hours, pack a large number of transactions, and obtain additional transaction fee income.

Therefore, in this offensive and defensive battle, the attackers are in the open, while the defenders are in the dark, and the attackers are in a passive position. In order to prevent the defenders from producing blocks, the attackers also need to increase their computing power, making mining in a loss state. This is a practice of hurting others 800 and losing 1000. This asymmetric offensive and defensive battle that is not favorable to the attackers continues to consume the attackers' resources.

Even if the attacker disregards rationality out of hatred and attacks at all costs, the defender can still abandon the attacker's chain based on consensus or take other temporary measures to resist computing power attacks.

Since BCHA has a core development team, firm supporters, and its own consensus community, and is traded on multiple important exchanges, it has a huge market. As long as the price is low enough, there will be a large number of buy orders, miners will be able to gain benefits, and there will be normal miners mining.

Therefore, as long as ABC does not give up and its supporters do not give up, BCHA cannot be killed by computing power.

This is the huge difference between the information world and the material world. In the material economy, the enemy can be completely killed through physical destruction, but in the information world, the opponent cannot be killed through computing power. The real victory lies in creating value in the market and gaining greater consensus.

13. Fork Wars and the Evolution of Cryptocurrencies

Decentralized cryptocurrency can be viewed as an evolving innovative experiment. From the expansion fork in 2017, to the BSV fork in 2018, to this offensive and defensive battle, the three forks have revealed important issues with decentralized cryptocurrency.

The main problem exposed by the expansion fork in 2017 was the governance problem of the decentralized ecosystem, which has not been solved and continues to appear in new forms. The fork in 2018 showed that the decentralized community was unable to resist organized centralized attacks. This offensive and defensive battle was directly caused by the exploration of a new governance model (IFP) that led to the fork.

The 2018 fork showed another important question: Do decentralized cryptocurrencies need to continue to evolve, or return to the classics to maintain stability? A large number of people who support CSW, especially developers, are formally attracted by CSW's return to the classic route.

This offensive and defensive battle also reveals a deeper question: Should the minority survive? I have mentioned this question in both the 2016 and 2018 battles. I believe that since it is an innovative field, it is difficult to determine a path that will definitely lead to success. Major and irreconcilable differences should be forked. After the fork, the minority should survive and retain an extra possibility of success.

Unfortunately, all three forks were filled with cries and actions to kill the minority. Previously, BTC supporters and BSV wanted to kill BCH, and this time it became BCH supporters who wanted to kill BCHA.

During and after the BSV fork, the BCH community as a whole maintained a tolerant attitude and was always on the defensive, never launching a hashrate attack on the BSV chain. Why is it so harsh on BCHA this time? It is puzzling.

14. The value and enlightenment of offensive and defensive battles

In the research of the previous two forks, governance issues and the survival rights of the minority have become the focus of my attention. In the long run, I think this is the key to the success of decentralized cryptocurrency. If effective governance cannot be achieved while maintaining decentralization, the road to success will be very long.

To this end, I started looking for solutions in 2017, and was verified and inspired by the evolution of BCH. In the Freecash (FCH) system launched on January 1, 2020, I inherited the successful experience verified by BTC, BCH and other cryptocurrencies, and also made some deductions and new designs.

In terms of governance mechanism, we use the prisoner’s dilemma between ABC and donors as a reference to divide governance into two layers: First, the governance fund must be publicly produced and cannot rely on donations. Second, we explore the decentralized governance fund operation model to prevent public funds from causing the centralization of the ecosystem. The experiment has achieved initial success.

In terms of consensus disagreements and minority survival issues, the principle of free forking was established, inheriting BCH's block-by-block difficulty adjustment mechanism (DAA) and reorganization protection, allowing the minority to survive after the fork.

As a new chain using the SHA256 algorithm, it can be said that FCH was born as an absolute minority. To this end, FCH made more modifications to the Bitcoin framework. Interestingly, these modifications and related deductions were practiced and verified in this BCHA attack and defense battle.

For example, the block time is shortened to 1 minute. This makes FCH's difficulty adjustment speed 10 times that of BCH. As a result: 1) The difficulty of BCHA is adjusted to normal after 5 days after the fork, while FCH only needs half a day in the same situation. 2) When encountering an empty block attack or a difficulty bomb attack, the time for normal block generation and difficulty recovery, and the defensive computing power requirements are reduced to 1/10.

Another example is to extend the output maturity time. In this attack and defense war, the attacker can sell the mined BCHA on the market. FCH has designed a 10-day mining output maturity period and a 100-day governance fund maturity period. This makes: 1) the risk and loss of the attacker greatly increased, 2) when the fork occurs, the cost of the majority killing the minority is greatly increased.

This attack and defense exercise rehearsed the empty block attack, dust attack, orphan block attack and other situations that were considered when FCH was designed. The attack is still ongoing, and it is very likely that there will be attack and defense methods that were not thought of before.

In addition, in the information world, the success of a decentralized ecosystem ultimately depends on a group of people who share common ideals and are willing to take action. As long as this consensus does not disappear, the ecosystem can continue. Establishing a consensus that can create value, share value, and benefit society is the source of power for survival and development. Our cognition should rise from world currency to free consensus.

(Image from NullTX)