Monero is under attack by Qubic, one of its largest mining pools. The pool aims to capture 51% or more of the network's hashrate between August 2 and 31 to test a hybrid form of mining called uPoW (Useful Proof of Work). According to Qubic, this attack is benign. However, some in the community are concerned that this centralized advance could lead to the introduction of orphaned blocks or double-spending on the private transaction network.

Qubic, which is also a cryptocurrency network, is led by Sergey Ivancheglo, the co-founder of IOTA, who has made several comments regarding the experiment, seeing Monero as a supposed proof of concept.

"Like the Monero community, I am seeking a countermeasure to Qubic’s 51% dominance. This is critical for the cryptocurrency industry as we may all face a non-benevolent attack one day. To raise awareness, first among XMR holders and then among everyone else, I suggest that Monero pools stop reporting their hash rate to sites like https://miningpoolstats.stream for a while. The Qubic pool will start doing so next Wednesday."

Sergey Ivancheglo, leader of Qubic.

According to Ivancheglo, one of the motivations for cornering the XMR hashrate is economic. His idea is to "bankrupt the botnet owners who have been stealing the revenue from honest Monero miners for years." His incentive plan to achieve this is as follows:

Miners in its pool will continue to mine XMR, but will be paid in Qubic tokens. The company will then sell their XMR holdings to buy more Qubic tokens or burn them, driving up the price of Qubic (and potentially, XMR itself). Motivated by these incentives, more miners could join the Qubic pool, ultimately cementing its dominance of over 50% of the network's hashrate.

The well-known consequences of a 51% attack on Monero are worrying the community. With that amount of hashrate in its possession, Qubic could censor transactions, orphan blocks on the network, or delay transaction confirmations in the mempool.

This community isn't sitting idly by, even though Monero's vulnerability is exposed. Some users are proposing network forks and changes to its incentive model, such as a transition to proof-of-stake (PoS), which would encourage more people to participate since it wouldn't require specialized ASIC equipment. At the time of writing, Qubic is the second largest Monero (XMR) pool, with 534.90 gigahashes per second (GH/s).