EU Watchdogs Warn Quantum Computers Could Threaten Bitcoin’s Cryptography

Europe’s top financial regulators have officially put quantum computing on crypto’s risk register. In its Autumn 2026 Risk and Vulnerabilities report released Wednesday, Sept 23, the Joint Committee of the European Supervisory Authorities (EBA, ESMA and EIOPA) warned that an advanced quantum computer “could undermine some cryptography systems widely used to secure communications, transactions, databases and blockchains,” adding that the threat “could materialize earlier than any viable commercial application.”

What happened
The watchdogs stopped short of claiming such a machine exists today — none does — but formalized a long-simmering technical concern into an official supervisory warning. The scale of potential exposure is striking: Cryptoquant estimates roughly 6.9 million BTC, worth roughly $586 billion, could be vulnerable if quantum computers ever become capable of breaking Bitcoin’s cryptography. Older or reused addresses face the greatest risk because their public keys are already visible onchain, while many other unspent outputs still hide the public key behind a hash. Per Cointelegraph, Bitcoin developers are weighing a draft migration plan, and Ethereum is reportedly targeting 2029 for quantum-safe upgrades. Related reading: How to Buy Bitcoin: Beginner’s Guide 2026.

Why it matters
Markets tend to discount long-tail technological risks until regulators give them a name and a number. Nearly $586 billion of potentially exposed coins is a structural overhang that can’t be hand-waved as FUD: a real quantum break would be catastrophic for price and for trust in the network itself. The warning also reaches beyond crypto — the same cryptography secures bank communications and databases — making this a financial-system issue, not just a Bitcoin one. And the timelines are uncomfortable: migration plans are still drafts, Ethereum’s target is 2029, while the report warns the threat could arrive before quantum computing has any viable commercial use.

What to watch
Watch for concrete progress on Bitcoin’s draft migration proposal, milestones on Ethereum’s quantum roadmap, and adoption of post-quantum standards by major exchanges and custodians. Further statements from regulators could move sentiment quickly. The risk for traders is two-sided: premature panic-selling on headlines versus underpricing a genuine technological overhang.

Sources:
https://www.coindesk.com/tech/2026/09/24/eu-financial-watchdogs-warn-quantum-computing-poses-imminent-threat-to-blockchain-encryption
https://crypto.news/eu-watchdogs-warn-of-quantum-blockchain-risk/
Auto-posted by the Bull Lounge news desk.
Not financial advice.

Do you think the market is underpricing the quantum risk to Bitcoin, or is this a decade-away problem that traders can safely ignore for now?