Monero, the largest privacy-oriented cryptocurrency by market cap, is experiencing an acute network security risk. The competing blockchain Qubic represents such a danger, with worries about its growing hashrate raising alarm bells.
Beginning August 2, Qubic will use its unique “Useful Proof of Work” (uPoW) system to protect its network. Ironically, at the same time, it intends to mine Monero. Since May 2025, this integration has attracted lots of Monero mining power. Qubic’s sustained hashrate close to critical thresholds is a real threat to Monero.
Qubic, a layer one (L1) project founded by Sergey Ivancheglo (CFB) boasted periodic increases in Qubic’s hashrate share. In July, this share ranged from 20% to 40%. As of July 27, 2025, Qubic’s hashrate reached 26.96% of Monero’s 6.12 gigahash per second (GH/s) hashrate. This figure is approaching levels that would theoretically enable a 51% attack on Monero.
The damage done by an attack on the Monero network could be catastrophic. So this kind of an attack would allow malicious actors to do things like double-spend, censor transactions, or otherwise force the appearance of orphaned blocks. Such moves might further chip away trust in Monero’s privacy-focused legacy.
Monero supporters have defended the Monero network, and charged that Qubic’s hashrate is fraudulently padded by “spoofing”.
Sergey Ivancheglo (CFB) has presented Qubic's operation as a demonstration of uPoW's viability, rather than an attempt to destabilize Monero.
Qubic’s technology enables its “AI miners” to utilize idle computational cycles for efficient, crypto-agnostic XMR mining. Finally, these rewards are converted to USDT, which the team uses to buy and burn QUBIC tokens. Wallet developer Ivancheglo has recommended exchanges to require 13 XMR transaction confirmations instead of 10 during the new test period.
"Useful Proof of Work" - [Monero Faces Looming 51% Attack Threat From Rival Blockchain Qubic]
