Sergey Ivancheglo, the co-founder of IOTA also known by the alias CFB, has become the central figure in an emerging network security controversy. Through his blockchain initiative Qubic, which employs a novel incentive structure called "useful proof of work" (uPoW), Ivancheglo has orchestrated a significant shift in the computational landscape of the Monero network. Beginning in May, the hash rate contribution from Qubic has experienced dramatic growth, escalating from under 2% to approximately 27% by early August—a period of just a few months that has triggered substantial backlash within the cryptocurrency community. This concentration of mining power has ignited serious discussions about the long-term sustainability of Monero's decentralized architecture and the potential vulnerabilities it could create.

When confronted with concerns about his actions, Ivancheglo characterized the initiative as an "economic demonstration" meant to showcase Qubic's technological capabilities rather than any deliberate effort to compromise the network. However, he notably acknowledged that the mining campaign could substantially affect how the Monero blockchain operates under normal conditions. Beyond these statements, Ivancheglo announced that starting in August, Qubic would cease publishing detailed information about its hash rate contributions to the network. According to Ivancheglo, this decision stems from his intent to "raise awareness of the risks associated with centralized control"—specifically the threat of 51% network dominance—underscoring the delicate balance required to maintain true decentralization in blockchain systems.