Europol warns crypto wallets are primary risk for quantum computing attacks

A Europol report published on October 7, 2026, warns that cryptocurrency wallets, rather than blockchains themselves, are the primary point of exposure to future quantum-computing attacks. While quantum computers capable of such attacks do not yet exist, up to 6.9 million bitcoin sit in vulnerable addresses with exposed public keys. Upgrading the decentralized Bitcoin network presents severe coordination challenges, as post-quantum signatures are 10 to 120 times larger than current standards and could overload block space.

Vulnerability of cryptocurrency wallets

• ▪A sufficiently powerful quantum computer could derive a private key from an exposed public key to spend associated funds without authorization.
• ▪The hash functions securing blockchain histories and mining remain highly resistant to quantum attacks compared to public-key cryptography used for wallets.
• ▪Approximately 6.04 million to 6.9 million bitcoin sit in addresses with exposed public keys, which cannot be secured retroactively against quantum attacks.
• ▪A Europol report published on October 7, 2026, states that cryptocurrency wallets, rather than blockchains themselves, are the primary point of exposure to future quantum-computing attacks.

The threat of harvest now decrypt later

• ▪Europol's report found no clear evidence that the 'harvest now, decrypt later' technique is being systematically exploited at scale, noting that government and business data are the most plausible targets.
• ▪Europol's second report, developed with Spain's University Carlos III of Madrid, warns that attackers are collecting encrypted data today to decrypt it later using quantum computers.

Challenges of migrating blockchain networks

• ▪A 2024 study cited by Europol estimates that migrating every Bitcoin unspent transaction output to a quantum-resistant format would require 76 days of cumulative block space or downtime.
• ▪Post-quantum signature schemes can be 10 to 120 times larger than Bitcoin's current Elliptic Curve Digital Signature Algorithm signatures, threatening to overload block space and raise fees.

Cryptocurrency industry migration efforts

• ▪In July 2026, nine firms, including BlackRock and Coinbase, pledged $15 million over three years to fund Bitcoin security research, including quantum defenses.
• ▪Ripple and the Stellar Development Foundation have published migration roadmaps, while Coinbase's quantum advisory council urged developers in June 2026 to begin post-quantum migration work.

Timeline for quantum computing development

• ▪Microsoft expects scalable quantum computing by 2029, while Bitcoin researchers and institutions increasingly view 2029 as the deadline for quantum-resistant migration plans.
• ▪A 2025 survey of 32 experts placed the probability of a quantum machine breaking RSA-2048 encryption within 24 hours in the next decade at 28% to 49%.
• ▪IBM's roadmap targets a fault-tolerant quantum computer by 2029, and the company expects quantum computing to generate significant commercial revenue within two to four years.

Government and regulatory response strategies

• ▪Europol recommends establishing a European Commission-led working group, including Europol, ENISA, and the EU Anti-Money Laundering Authority, to regularly brief policymakers on quantum threats.
• ▪The U.S. National Institute of Standards and Technology has proposed deprecating today's most common public-key configurations by 2030 and phasing out classical public-key cryptography by 2035.
• ▪The European Union's NIS Cooperation Group has recommended that member states adopt a post-quantum migration strategy by the end of 2026.

Debatable claims

• ▪The Bitcoin network should freeze dormant Satoshi-era wallets to prevent quantum theft
• ▪State-led working groups are inappropriate for coordinating decentralized cryptocurrency defenses
• ▪Preventing quantum attacks matters more than keeping Bitcoin transaction fees low