The combined computing power of the top two BTC mining pools has exceeded half, making it possible for them to jointly initiate a 51% attack.

A few days ago, the article on the teaching chain introduced the Qubic Mining Pool being suspected and its claim that it successfully implemented a so-called 51% Attack on Monero by controlling more than half of the total Computing Power of Monero, thus excluding other Miners through selfish mining and achieving a monopoly on the accounting rights.

Yesterday, on August 19th, netizen @l3olanza discovered that the combined Computing Power of the two largest BTC Mining Pools has already exceeded half of the total Computing Power of the entire network. This means that if they collude, they may have the conditions to carry out a 51% Attack on the BTC network.

The two major mining pools are Foundry USA, which accounts for 33.6% of the computing power, and AntPool, which accounts for 17.9%. Together, they account for 51.5% > 51%.

In this regard, netizen @CPOfficialtx believes: "It requires two mining pools to collude to pose a threat to BTC... but this situation may not occur. No one, including miners, wants to suffer losses. However, this is not the first time that two or more mining pools have controlled over 51% computing power."

Netizen @uonnaberich pointed out a historical case: "This statement is not accurate. If miners detect malicious behavior, they can easily switch mining pools. This situation occurred in 2014—when the computing power of the GHash.io mining pool approached 51% of the BTC network, miners spontaneously withdrew, causing its share to drop back to around 38%, quickly restoring ecological balance."

Netizen @JacobKinge was horrified to discover, "Foundry USA has just mined eight blocks in a row. This is simply shocking! Even many BTC veterans I know are starting to panic. For years, I've been warning everyone: the degree of centralization of BTC has become extremely dangerous. A small group of miners and insiders control the network and manipulate prices, and this incident is the latest solid proof. There's an even more dangerous signal: now the blocks are completely empty, and transaction fees have plummeted to 1 sat/byte. Seriously, no one is using BTC anymore."

Netizen @JeffPasquino pointed out that this is just a simple probability problem: "As of last year, Foundry's computing power accounted for about 32%. The probability of mining 7 consecutive blocks is only 0.03% (about 1 in 3300). But the key is: after mining one block, what is the probability of mining another 6 consecutively? And how long should it take them to mine a block? Based on a third of the computing power, Foundry should be able to mine 2 blocks per hour—i.e., 48 blocks per day. The probability of mining 6 consecutive blocks is 0.1%. Therefore, the probability of Foundry mining 7 consecutive blocks on any given day is 4.8%. This also means that the probability of achieving such a consecutive mining record once a month (>1%) far exceeds the mathematical expectation. Mathematics is really interesting."

Netizen @CsTominaga sarcastically said: "Ah, the believers have started to make a fuss again – Foundry has mined eight blocks in a row, and it's as if the sky is falling. Mastering 40% of the Computing Power to mine eight in a row? This is not black magic, just probability taking a stretch. The fifth chapter of the BTC white paper has made it clear: miners and nodes are one, and the active ones have never exceeded twenty or thirty. Right now, there are probably just 13. So this performance is not evidence that decentralization is dead, it's just math paying rent on time."

But panic is always more fashionable than arithmetic. If Wilde were alive, he would surely appreciate this absurd drama: gentlemen shouting at empty blocks, as if they had stumbled upon a séance. Bukowski would probably spit and bluntly say—this is just a trick to scare people in a shabby bar, where they haven't sold real drinks for a long time. If Pratchett were still writing, he would surely compare it to watching the crooked wheels of Ankh-Morpork's carts: those wheels have never been round, and now they are surprised that they don't roll straight.

In the past, Jiao Lian has mentioned that for heavy PoW chains like BTC, a 51% attack is difficult to steal coins by rewriting historical data, nor can it crack anyone's address private key. In fact, even for the vast majority of people with small transaction amounts, conducting a double-spending attack is not worth the cost.

Historically, double-spending attacks that occurred on other PoW chains with insufficient weight were executed using a 51% Attack to deceive centralized exchanges, repeatedly depositing and withdrawing coins to achieve fake deposits. Once successful in making the exchange mistakenly believe that a large amount of assets had been deposited, but in reality, they had not been credited, one could then realize a profit through other means. For example, one method is to short sell using the coins from the fake deposit, leveraging global price correlations to open short positions in advance on other trading platforms to exit profitably.

The selfish mining attack on Monero mentioned at the beginning of this article by a certain mining pool is a new strategy that utilizes a 51% attack. If we ask whether Foundy USA and AntPool will join forces to engage in such selfish mining, improving the treatment of miners in their own mining pool to attract more miners' computing power, thereby further expanding their control of computing power until they eventually monopolize BTC block production, i.e., the right to keep accounts, it depends on whether they are willing to sacrifice their reputation to collude. What conditions can they offer miners as a bribe, and whether miners in the entire BTC community prioritize profit over everything else, going where the money is, or if they will balance short-term gains with long-term interests, thus considering the long-term development of BTC, refusing to cooperate with mining pools that violate BTC's values, and refusing to use their own computing power to help mining pools achieve monopolies.

Ultimately, it is a test for the community.

No matter how perfect the design and mechanism are, they cannot withstand the corruption of the hearts of the entire community and their self-indulgence.