Europol has identified cryptocurrency wallets as the primary exposure point for quantum computing threats, warning that sufficiently powerful quantum computers could derive private keys from exposed public keys to unauthorizedly transfer assets. The European Cybercrime Centre noted that while hash functions securing blockchain mining remain relatively quantum-resistant, wallets with publicly exposed keys cannot be remediated after the fact and require proactive fund migration before quantum attacks become viable. Glassnode estimates approximately 6.04 million BTC, representing 30.2% of Bitcoin's circulating supply, currently have exposed public keys. However, transitioning to post-quantum cryptography presents significant challenges: NIST-standardized signatures are 10 to 120 times larger than current ECDSA signatures, potentially increasing block space pressure and transaction fees. Research suggests migrating all unspent Bitcoin transaction outputs to quantum-resistant systems would require at least 76 days of network processing time. Rather than predicting a crypto collapse, Europol recommends a phased migration to post-quantum cryptography and enhanced key management. The agency highlighted "instant attacks" during the brief window between public key exposure and transaction confirmation as a more realistic near-term risk than retroactively cracking historical transaction data.