EU regulators warn quantum threat to Bitcoin could precede commercial viability

European financial authorities warned that an advanced quantum computer could undermine cryptography used to secure blockchains. They said the threat could emerge before the technology has a viable commercial application. According to CryptoQuant, roughly 6.9 million bitcoin worth roughly $586 billion are currently vulnerable if quantum computers become capable of breaking Bitcoin's cryptography. The warning appeared in the Autumn 2026 Risk and Vulnerabilities report released Wednesday. The report said advanced quantum computers could undermine cryptography systems used to secure communications, transactions, databases and blockchains. The Joint Committee of the European Supervisory Authorities includes the European Banking Authority, the European Securities and Markets Authority and the European Insurance and Occupational Pensions Authority. Bitcoin's shift to quantum-resistant security would require networkwide consensus and the transfer of exposed coins. The European Commission has urged member states to begin post-quantum transitions by the end of 2026. The report did not give a timeline for quantum computing to become commercially viable. A recent IBM report says quantum computing will be in use in four years or less.