Kraken suspends Monero deposits after 51% attack

Crypto exchange Kraken has announced the suspension of Monero (XMR) deposits following a confirmed 51% attack on the network on August 12. The attack was linked to the Qubic mining pool, which managed to control over half of Monero’s hashrate, peaking at 2.6GH/s.

This dominance allowed Qubic to conduct a six-block deep reorganization of Monero’s blockchain, effectively rewriting history and orphaning around 60 blocks. The attack exposes the vulnerability of mid-tier Proof-of-work networks like Monero to majority control maneuvers.

Kraken follows ‘security precaution’ with Monero

Monero is a privacy-focused coin designed to provide secure, anonymous, and untraceable transactions. Unlike transparent blockchains such as Bitcoin and Ethereum, Monero conceals the sender, receiver, and amount for every transaction, and is popular among users who value financial privacy and freedom.

Launched in April 2014, Monero has suffered previous security incidents, including a flooding attack in March 2024 that congested the network. However, the recent 51% attack is the first major breach of Monero’s consensus protocol, heightening community concern about mining concentration and network resilience. Kraken posted:

“As a security precaution, we have paused Monero (XMR) deposits after detecting that a single mining pool has gained more than 50% of the network’s total hashing power. This concentration of mining power poses a potential risk to network integrity.

We are actively monitoring the situation and will resume deposits once we determine it is safe to do so. Trading and withdrawals for XMR remain fully operational.”

Lack of official communications makes Monero look ‘weak’

Monero’s price has fallen by as much as 14%, with the episode reigniting concerns about the centralization of mining in privacy-centric cryptocurrencies and the market impact of such attacks.

While security analysts are still debating the degree to which the reorganization constituted a full 51% attack (some argue it was a stress test on Monero’s decentralization rather than a purely malicious assault), a lack of official communications are conspicuous by their absence, as privacy-centric Unstoppable Wallet posted:

“To be honest, we kind of deserve this…

Zero unified pushback, no official statements, outdated website, passive devs.

Meanwhile Qubic, despite not actually hitting 51%, are winning the info war simply by being loud.

Monero community looks weak.

It’s both pathetic.”

As exchanges like Kraken take protective action, the broader crypto community will need to reconsider the resilience strategies for networks with smaller mining populations, as regulators highlight the added risk of privacy coins in centralized trading environments.

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