Qubic Targets 51% of Monero Hashrate, Faces Community Resistance

Qubic rapidly expanded its control over Monero’s mining network, growing from less than 2% to over 27% of the total hashrate since mid-May 2025. The project, led by IOTA co-founder Sergey Ivancheglo, now plans to control 51% of Monero’s mining power between August 2 and August 31.

Qubic achieved this growth by offering token payments to CPU miners through what it calls “useful proof-of-work” technology. The project converts mined Monero into USDT, then uses those funds to buy back and burn its native QUBIC tokens.

Ivancheglo announced the 51% plan on social media, calling it an “economic demo” rather than an attack. He stated that once Qubic reaches majority control, it could start rejecting blocks from other mining pools, potentially orphaning blocks and delaying transactions.

The Monero community reacted quickly. Within days of the announcement, Qubic dropped from first place to seventh place in mining pool rankings, according to MiningPoolStats data. At its peak in July, Qubic controlled around 40% of Monero’s hashrate before settling at 27%.

Monero developers and miners expressed concerns about network security. Dan Dadybayo from Unstoppable Wallet said that with 51% control, Qubic could “orphan blocks, reject transactions, delay confirmations, suppress competition and force protocol changes.” He added that “intent doesn’t matter” because centralization creates risks regardless of stated purposes.

The controversy spread beyond mining circles. Social media posts warned that financial incentives can compromise Monero’s security model, with one analyst writing, “They’re not hacking your privacy—they’re buying it.”