17.08.2025 17:53

Kraken exchange, a prominent cryptocurrency platform, proactively suspended Monero (XMR) deposits as a precautionary measure. This action followed reports suggesting a single mining pool, Qubic, potentially controlled over 50% of the Monero network's hash rate, raising concerns about a potential 51% attack. The suspension, a temporary safeguard, aimed to protect user funds and maintain the integrity of the platform.

While trading and withdrawals remained unaffected, the pause highlighted the vulnerability inherent in proof-of-work cryptocurrencies to such attacks. A 51% attack, where a single entity controls a majority of the network's mining power, grants the attacker the ability to manipulate transaction history, potentially reversing or blocking transactions. Qubic's public announcement of exceeding the 50% threshold, coupled with its urging of other miners to join its pool, fueled these fears, though the messaging itself was interpreted by many as an attempt to consolidate power.

However, independent network data painted a less alarming picture. While Qubic's hash rate fluctuated and, at times, briefly surpassed 50% due to the use of selfish mining tactics — a strategy that artificially inflates apparent control — its consistent share remained closer to 35-38%. Selfish mining, a technique where blocks are temporarily withheld before release, can create a deceptive impression of higher dominance, making the true distribution of mining power difficult to accurately assess in real-time. Kraken's decisive action underscores the challenges involved in maintaining security within decentralized crypto networks and the importance of careful monitoring of mining power distribution. The exchange will reinstate Monero deposits only when network stability is confirmed and the risk of a 51% attack is mitigated. This incident serves as a reminder of the ongoing tension between decentralization and security in the cryptocurrency space.