Monero, the leading cryptocurrency dedicated to privacy, faces one of the most serious security challenges in its history.
Quubic, a project led by IOTA co-founder Sergey Ivancheglo, says today Controls more than 51% of the network hashrate. In blockchains secured by proof-of-work algorithms, that is the same method used by Bitcoin, the control level may allow an attack to re-write transaction history, block transactions or perform double rotation attacks.
In a Blog postQuibic described the acquisition as a “experiment” that is a “strategic, and sometimes combined, application the theory of the game.”
Developers, miners and security experts are now debated if the network’s decentralization is as strong as many believe.
What is a 51% attack?
In a Proof-of-work blockchainMiners compete to add new blocks of chain transactions. If a group controls more than half of the total computing power, they can exceed each other participant.
The level of that control The door opens in a set of capabilities that can break confidence in the network. This includes chain repairs, which are usually shortened to “Reorg,” which involves replacing previously confirmed blocks with new ones. It also covers double spending, which means sending the same token twice,
Reasonable the most affecting part of a 51% attack is the transaction of transactions – expressing some payments from confirmation – specifically related to Monero’s case that has given its focus on privacy
These attacks are not theoretical. The Ethereum Classic is that -hit many times in 2020worth millions. Bitcoin Gold faces similar incidents in 2018 and 2020. Smaller tokens such as Verge have been targeted and proven.
Why is Monero still at risk
Monero uses Randomx Algorithm to discourage mining using specific application integrated circuit (Asics)CPU mining is encouraged instead. This design is meant to maintain network decentralized. That is why the rapid increase of quubic is so important. From less than 2% of Monero’s hashrate in May, it grew more than 25% in late July, and is now said to have crossed a 51% threshold.
Quubic runs a “useful proof-of-work” system that turns Monero’s mining rewards to the USDT, then uses those funds to buy and burn own quubic tokens. The mechanism is not uncommon, combining a mining approach with a token supply zinc. And this continues to increase the control of the Qubic in Monero’s hashpower.
Qubic only reached the 51% part of Monero. This is a great deed. They were the first to manipulate a cryptocurrency with 51% attack. They aim to orphaned all the blocks from each other miner, making themselves the only creature of Monero’s mining. The only way Monero’s mine is … pic.twitter.com/riihj5ctpo
– Caffeinated user | ꓘ & ױ (@caffeinateduser) August 11, 2025
Ledger cto charles guillemet Says That “maintaining this attack is estimated to cost $ 75 million per day,” before adding that while it is potentially benefiting, “it threatens to destroy the network trust almost overnight. Other miners are left without incentive to continue.”
Bitmex research added: “Qubic says the purpose of the end is to get all the rewards of the Monero block, which means that it means full and sustainable selfish mining. It is unclear whether they can actually achieve that. If it can be achieved, the amount of coin can fall.”
It was made. Monero’s XMR is currently trading at $ 252, down 6% in the past 24 hours to compound a 13.5% decline over the past seven days.
What does this mean for Monero?
In the blog post, Qubic said the acquisition was not about destroying the Monero, but about proving that economic incentives and a coordinated mining strategy could provide a smaller protocol that effectively controls a larger.
The experiment, says Qubic, is to test if mining resources can earn transferred from a target network to another loop of economic protocol.
At its peak, the Qubic claims that Monero’s mining is almost three times more benefit than Monero’s traditional mining. A repair of its reward system, approved by its community, strengthened payouts on its validators and drawn miners away from other Monero pools.
Quubic reaches more than 51% of Monero’s hashrate, which effectively provides network control.
Quubic chose not to launch further extraction, proving a strong theory through action.
But this story is not over yet. What is next for the quubic and the future of chains?
Below article⏬ pic.twitter.com/jqqnqpy95j
– Quubic (@_quubic_) August 12, 2025
The first quubic push for most control was met with long-distributed denial-of-service (Ddos) Attacks interrupted peripheral services for more than a week but failed to overthrow its main network.
DDOs attacks continued on Tuesday, Ivancheglo announced to X, on what his decribes as “Monero Maxis returning the favor.”
The Quubic says that to this day has ceased to complete the consensus, citing concerns about the potential impact on XMR prices.
Other blockchains are vulnerable to attack?
The hashrate of Bitcoin is so high that a 51% attack will not be loved. But mid-tier proof-of-work coins are weaker. The cost of having a majority hashpower in Monero, Ethereum Classic or Bitcoin Gold is lower.
Privacy -focused coins face an extra challenge. Their censorship -resistant nature means that if a party controls the network, it overthrows the privacy itself designed to protect.
