EU Warns of Quantum Threats, Calls for On‑Chain Spending Caps and Circuit Breakers

European Supervisory Authorities (ESAs) have issued a warning that quantum computing could compromise cryptographic systems used by blockchains and financial services as early as 2026. The warning ties into the EU’s Digital Operational Resilience Act (DORA), which now requires financial entities to transition to quantum‑resistant algorithms.

Urgent Migration for Major Layer‑1 Networks

Experts highlight that Bitcoin, Ethereum and Solana rely on elliptic‑curve signatures that are vulnerable to future quantum attacks. The networks’ upgrade paths are considered difficult, meaning a multi‑year effort will be needed to replace existing signatures with post‑quantum standards such as hash‑based STARKs.

Zero‑Knowledge and Storage Protocols Must Act Now

Protocols that store long‑term confidential data are advised to replace vulnerable key‑exchange and key‑wrapping mechanisms with vetted post‑quantum schemes. Elliptic‑curve‑based zero‑knowledge proofs are not automatically quantum‑safe; hash‑based alternatives should be evaluated and deployed where possible.

AI‑Enabled Exploits Prompt Call for On‑Chain Circuit Breakers

The ESAs also note rapid advances in artificial intelligence that could allow attackers to execute large‑scale exploits faster than traditional monitoring can respond. To mitigate this risk, developers are urged to embed spending caps, expiring permissions and protocol‑wide outflow limits directly into smart contracts, rather than relying on off‑chain alerts.

Regulatory Timeline

The EU NIS Cooperation Group recommends that member states adopt a post‑quantum cryptography migration strategy by the end of 2026, aligning with DORA’s requirements for financial entities.