The Qubic mining pool gained control of more than half of the computational power (hashrate) of the Monero network, enabling a 51% attack. According to some estimates, Qubic’s hashrate exceeded 53%, creating a risk of centralization and the potential for block reorganizations, transaction censorship, and double spending on the network.
This is reported by Business • Media
Details of the Attack and Community Response
The successful attack was reported by SlowMist founder Yuy Xian, noting the significant concentration of power within a single pool. He stated that Qubic could theoretically rewrite the blockchain, execute double payments, and block any transactions.
“Theoretically, Qubic, this mining pool, can rewrite the blockchain, execute double payments, and censor any transactions right now.”
The head of Qubic and co-founder of IOTA, Sergey Ivanchiglo, previously stated that the initiative’s goal is an “economic demonstration,” with no intention of disrupting the Monero network. However, concerns arose within the community regarding the potential consequences of such a concentration of hashrate.
According to SlowMist, at one point, Qubic controlled 52.36% of Monero’s hashrate, while other sources reported it was even over 53%, amounting to 2.65 GH/s. Following this, the price of XMR fell by 8%.
At the same time, some analysts pointed out the uncertainty of the economic benefits of such an attack due to the significant costs involved in maintaining it. For instance, Ledger’s CTO Charles Guillemet estimated daily expenses at around $75 million. He noted that Monero has limited options to address this issue, and a complete takeover of the network is a plausible scenario.
Discussion Around Hashrate and Future Developments
A community member using the pseudonym dkat, likely the head of Qubic’s core developers, commented that the team “besieged” Monero and “starved out” other miners, gaining at least three opportunities for reorganizing up to 10 blocks. However, he stated that Qubic has no intentions of taking harmful actions against the network.
Meanwhile, several experts questioned the success of the attack. Lead developer of SeraiDEX, Luke Parker, believes that in the case of a genuine 51% attack, there would be no blocks from other miners, and the Qubic team likely just took advantage of a fortunate coincidence. His opinion is shared by user tuxsudo, who also pointed out the disconnection of the public hashrate API by the Qubic pool.
According to MiningPoolStats, the two largest mining pools processed 44 out of the last 100 blocks on the Monero network, confirming the increase in centralization.
Qubic employs an economic incentive method – rewarding miners with QUBIC tokens, attracting operators to its pool. The mined XMR is exchanged for stablecoins and then for QUBIC, forming a sustainable economic model to support computational power.
Organizing a 51% attack opens the pool to manipulate blocks, execute double spending, and restrict transactions. Against the backdrop of this news, the price of XMR dropped by 8%:
At the same time, the price of QUBIC rose by 4% over the last day:
The experimental initiative by the Qubic team will continue until the end of August 2025.