EU Regulators Flag Quantum Risk to Bitcoin and Ethereum Security

Overview

• The Joint Committee of EU financial supervisors (EBA, ESMA, EIOPA) said in their Autumn 2026 assessment that quantum computing is an emerging risk for financial cryptography and urged stronger preparedness.
• Google Quantum AI’s 2026 paper sharply cut prior estimates for breaking 256‑bit elliptic‑curve signatures, citing roughly 1,200 logical qubits in some models and far larger physical qubit counts after error correction, while no quantum computer today can carry out such an attack.
• Bitcoin developers are debating draft BIP‑361, authored by Jameson Lopp and others, which would phase out ECDSA and Schnorr signatures once post‑quantum transaction types exist and would require protocol upgrades and users moving funds off vulnerable addresses.
• The Ethereum Foundation has formed a post‑quantum security team and set an internal goal to make execution, consensus and data layers quantum‑resistant by December 2029, and it says users do not need to act today because current funds remain secure.
• Regulators and standards bodies are already pushing migration steps that could affect exchanges, wallets and national infrastructure, and millions of bitcoins tied to address reuse are cited as a future exposure that makes coordinated upgrades and user action an urgent operational challenge.