The Monero (XMR) network, long regarded as one of the most resilient privacy-focused blockchains, has been shaken by claims that it suffered a 51% attack. Blockchain project Qubic, led by former IOTA co-founder Sergey Ivancheglo, announced it had gained majority control of Monero’s hashrate and executed a reorganization of six blocks, discarding roughly 60 blocks from the ledger.
Control of more than half the hashrate would give Qubic significant influence over the network, including the ability to censor transactions, reorder blocks, and potentially double-spend coins. These claims triggered alarm across the Monero community, raising questions about the integrity and decentralization of the project.
Kraken, one of the largest global cryptocurrency exchanges, took swift action by temporarily halting Monero deposits in response to the security concerns. The exchange later resumed deposits but introduced a stricter requirement of 720 confirmations before crediting funds to user accounts. Withdrawals and trading activity remained unaffected, but Kraken’s decision signaled a strong cautionary stance on the potential risks.
Community Division and Market Reaction
The Monero community has been divided in its response to the claims. Some developers and users argue that Qubic’s assertions reflect a stress test rather than a direct malicious attack, emphasizing that the integrity of the blockchain was not fully compromised. Others warn that the concentration of mining power, even temporarily, exposes the network to risks that could undermine its core principles of decentralization and security.
On Reddit and other community forums, skepticism has been widespread. Several users suggested that Qubic’s control was overstated, estimating its hashrate share to be closer to 35%. They highlighted that due to mining variance, even pools with less than 50% of total power can occasionally produce an outsized share of blocks in a short period of time. This, they argued, could explain the apparent dominance without necessarily implying true majority control.
Despite the doubts, the event had an immediate impact on markets. Monero’s price dropped by about 6.65% within 24 hours of the announcement and approximately 16% over the course of the week. However, the token later rebounded to trade near $276, suggesting that investors may have viewed the incident as disruptive but not existential.
Looking Ahead
The episode has reignited debate over the security of proof-of-work blockchains and the specific risks faced by Monero. While the project has long positioned itself as a decentralized and censorship-resistant network, the concentration of mining power in a single pool raises difficult questions about its future resilience.
For Monero’s developers and community, the challenge now is to assess whether the current consensus model provides adequate safeguards or whether changes are necessary to mitigate similar risks in the future. As exchanges and users remain alert, the incident serves as a reminder of the vulnerabilities that even established blockchains can face.
