On October 7, 2026, the European Cybercrime Centre (EC3) of Europol released two reports analyzing the impact of quantum computing on digital assets and encrypted data. The agency concluded that while blockchain networks like Bitcoin are generally resistant to quantum threats due to their reliance on hash functions such as SHA-256, individual wallets remain vulnerable.
The primary risk identified involves public-key cryptography. Europol reports that approximately 6 to 6.9 million BTC, representing roughly 30% of the total supply, are stored in addresses with exposed public keys. A sufficiently powerful quantum computer could theoretically derive private keys from these addresses to authorize unauthorized transactions.
Europol emphasizes that there is no retroactive way to secure these exposed keys. The recommended solution is a proactive migration of funds to secure wallets using post-quantum cryptography (PQC). However, the agency notes that coordinating such an update across the decentralized Bitcoin network presents a significant challenge.
The report estimates that migrating all unspent transaction outputs (UTXOs) could require over 76 days of cumulative processing time. Because the responsibility for moving funds lies with individual users, the agency warns that coins belonging to inactive owners may remain permanently at risk if they are not migrated before quantum technology advances.
