Qubic Shakes Monero: A Calculated Attack?
In a twist worthy of a crypto thriller, Qubic, a mining pool affiliated with IOTA, has shaken Monero (XMR) by claiming control of 51% of its hashrate on August 12, 2025, causing a 6-block reorganization and a 6.65% price drop.
Presented as a “stress test” by Sergey Ivancheglo, IOTA co-founder, this action highlighted a critical vulnerability in RandomX, Monero’s anti-ASIC algorithm. While the XMR community downplays the incident, debate about privacy blockchain security has ignited.
Indeed, Qubic, leveraging Useful Proof of Work (UPoW) for AI calculations, saw its Monero hashrate surge from 2% in May to 51% in August, mining 63 blocks out of 122 in a single day. This spike caused a 6-block reorganization without double-spending or prolonged censorship, but alarmed privacy advocates. A week-long DDoS counterattack slowed Qubic but didn’t eliminate the threat.
That’s why Joel Valenzuela, a key member of the Dash DAO, warns: “Monero remains vulnerable. Reorganizations could resume at any moment with standard hardware.” Charles Guillemet (Ledger CTO) and Yu Xian (SlowMist) doubt a sustained attack, estimating the cost at several million dollars with no clear gain.
RandomX: Monero’s Exposed Vulnerability
Monero (market cap of $4.5 billion), the leader in privacy cryptocurrencies, relies on RandomX to democratize mining via CPU/GPU, eliminating ASICs.
But this accessibility makes the network susceptible to economic attacks, as Qubic demonstrated by repurposing AI compute power to dominate the hashrate. Valenzuela compares this to Dash, which since 2019 has used ChainLocks (staked masternodes) to block 51% attacks, a solution impossible for Monero without a massive overhaul.
The Monero community is therefore exploring FCMP++ and CARROT to strengthen RandomX, but no immediate fix is ready. “This is a wake-up call,” notes a Monero developer on Reddit, highlighting the need for innovation in the face of modern compute pools.
Qubic’s Motives: Hype or Real Threat?
Valenzuela speculates that Qubic sought to promote its UPoW blockchain. Financially, mining XMR recycles compute power and then buying back QUBIC, offering an economic incentive. Moreover, Qubic is now targeting Dogecoin, signaling a growing threat to accessible PoW networks.
Valenzuela criticizes slow regulators, advocating for legal clarity like the US Clarity Act (2024), which legalizes cryptocurrencies without forced KYC. MiCA (EU) threatens privacy coins with increased surveillance, hampering adoption despite their utility for anonymous payments. “Consumer protection excuses don’t hold up,” Valenzuela insists.
In conclusion, Qubic’s attack exposes the limitations of RandomX, forcing Monero to rethink its security. Dash, with ChainLocks, offers a robust alternative, but the PoW challenge persists. For investors, XMR remains attractive but risky. Watch for FCMP++ upgrades and diversify with secure blockchains.
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