Europol Warns Bitcoin Wallets Face Quantum Computing Risk

Cryptocurrency wallets, rather than blockchain networks themselves, face the greatest threat from future quantum computing attacks, according to a new Europol report published Wednesday.

The European Union law enforcement agency said quantum computers powerful enough to threaten cryptocurrencies do not yet exist and offered no timeline for their arrival. Still, Europol expects “proactive adaptation, rather than systemic collapse” as the crypto industry prepares for the technology.

Europol urged Bitcoin and cryptocurrency developers to begin a phased transition toward quantum-resistant security through wallet upgrades, post-quantum cryptography and coordination between developers, miners, exchanges and users. Bitcoin researchers and institutions increasingly view 2029 as an important deadline for establishing credible migration plans.

A sufficiently advanced quantum computer could potentially derive a wallet’s private key from its exposed public key, allowing an attacker to spend the cryptocurrency it controls. However, Europol stressed that blockchain hash functions, including those protecting Bitcoin’s transaction history and mining process, are considerably more resistant to quantum attacks than the public-key cryptography securing wallets.

“Cryptocurrencies will not collapse due to quantum computing,” Europol said, emphasizing that asset ownership is the primary vulnerability rather than Bitcoin’s blockchain itself.

The risk is particularly significant for early Bitcoin addresses from the “Satoshi era” whose public keys are already visible onchain. About 6.9 million BTC are reportedly stored in addresses with exposed public keys, including early pay-to-public-key outputs and long-dormant wallets. Europol said these exposed keys cannot be retroactively secured, fueling debate over whether vulnerable Satoshi-era Bitcoin should eventually be frozen.

Migrating Bitcoin to quantum-resistant cryptography could also create substantial technical challenges. Europol cited a 2024 study estimating that converting every Bitcoin unspent transaction output, or UTXO, would require at least 76 days of total block space. Allocating only 25% of each block to migration could extend the process to roughly 300 days.

Post-quantum signature schemes could also be 10 to 120 times larger than Bitcoin’s current ECDSA signatures. Ultimately, Europol said Bitcoin’s biggest challenge may be achieving global consensus on new security standards before quantum computers become capable of targeting vulnerable wallets.