Did the hype come true? A brief recap of the Qubic double-spend attack

Qubic's claimed "51% attack" on Monero (XMR) is revealed to be a psychological operation rather than a genuine display of overwhelming computing power. The entity only temporarily reached around 35% hashrate, not the 51% required for a true majority attack.
The core tactic employed was selfish mining, where Qubic mined six consecutive blocks in secret before releasing them to create the longest chain. This action invalidates blocks mined by honest miners, a method that can theoretically enable double-spending, though no actual double-spend occurred.
Analysis shows that with 35% of the network's hashrate, such a selfish mining attack is statistically probable and could occur multiple times per day, making it a credible threat.
The primary goal appears to have been psychological warfare and intimidation. Following the event, many miners joined the Qubic pool out of fear that their future blocks would be invalidated, which ironically pushed Qubic's actual hashrate above 50% after the fact.
The incident is characterized as a "Fake it till you make it" strategy, using propaganda and the threat of attack to create a real computing power hegemony by coercing miners to join their pool.
Qubic has since announced Dogecoin as its next target, a move perceived as an extension of its psychological warfare campaign, though attacking an ASIC-based network like Dogecoin may present greater technical challenges.

Some follow-up: This is fascinating, and it's a bit of psychological warfare. Since last week's announcement of a 51% attack on $XMR by Qubic, the community has come to several conclusions after reviewing the situation:

1. During the so-called 51% attack last week, Qubic did not actually possess 51% of the computing power; it only temporarily reached around 35% for a short period of time.

2. Qubic has produced six consecutive XMR blocks, which is suspected to be selfish mining.

Selfish mining involves mining blocks but not announcing them until six have been mined, then releasing them all at once to create the longest chain. This renders the five blocks (the second longest chain) of the honest miners useless, thus enabling double spending.

PS: I, a soul painter, made a rough sketch for your reference.

In fact, even if I only have 1% of the computing power, I can theoretically mine 6 blocks in a row, but the probability is too small, while the probability with 35% computing power is quite high.

I did some simple calculations. This is just natural probability. Based on Monero's 1440 blocks per day, a 35% hashrate would mathematically allow for 2.6 successful attacks per day.

This does not include the bonus of selfish mining, which would be even higher if it were included. Otherwise, Qubic might not be willing to spend money to rent computing power in a short period of time to reach 6 yuan.

Why is this model called selfish? Because when blocks are held back, in order to ensure the success rate, they often do not contain transactions, resulting in many empty blocks, wasting block space.

Let’s get back to the point. Qubic doesn’t have double spending. Many exchanges require 10 blocks to confirm XMR deposits. Of course, it has no motivation to actually attack.

So you can understand that Qubic has neither 51% computing power nor 51% attack capabilities. It just flexed its muscles briefly and then released a promotional article, claiming to have completed a 51% attack.

But why is it called psychological warfare? Because after the incident, many miners actually surrendered and joined the Qubic mining pool. As a result, as of yesterday, Qubic's computing power actually exceeded 50%.

So this is not a battle of computing power, but a psychological battle.

This is a kind of deterrent to miners - if you don't join Qubic's mining pool, then the blocks you mine in the future may be invalidated, affecting your harvest; if you join, although it is like aiding and abetting the evil, not only will you suffer losses, but you may even be able to double-mine. Not all miners are tough, and many still have to consider the economic benefits.

Soon after, they officially announced that their next target would be Dogecoin. However, I suspect that since Dogecoin is based on Litecoin mining hardware, which uses ASICs, it might not be that simple. However, they are masters of psychological warfare. Therefore, this official announcement itself could be a new form of psychological warfare.

It's amazing. This is called Fake it till you make it. It's hard to translate. The literal translation is: "Fake it till you make it until it becomes true."