Europe’s three financial supervisors have added quantum computing to the risks facing the financial system, warning that the technology could one day undermine the cryptography that secures blockchains. The caution appears in the European Supervisory Authorities’ Autumn 2026 risk update, published on September 23, and it gives regulators’ weight to a debate that has mostly played out among protocol developers and cryptography researchers.
What the regulators actually said
The passage is short but specific. The authorities (the European Banking Authority, the European Securities and Markets Authority, and the European Insurance and Occupational Pensions Authority) describe quantum computing as a technology that could soon reshape pricing, fraud monitoring and compliance work. They add a caveat in the same breath: it could also create major risks by undermining the cryptography widely used to secure communications, transactions, databases and blockchains.
The timing is the striking part. The regulators say these risks could materialise faster than any commercially viable application. In other words, the danger to encrypted systems may arrive before the promised productivity gains do, leaving institutions exposed during the gap between capability and payoff.
The distinction matters because the two timelines point in opposite directions. The financial sector’s interest in quantum computing is driven by the promise of faster pricing, better fraud detection and cheaper compliance. The security concern is driven by the opposite scenario, in which the same capability is turned against the encryption that underpins payments, identity and custody. The authorities are effectively asking institutions to prepare for both outcomes at once, rather than waiting for the technology to arrive before deciding how to respond.
A warning inside a wider risk outlook
The quantum finding is one strand of a broader assessment that names external dependencies, emerging technologies and private credit as the main vulnerabilities for the EU financial system. The authorities are especially concerned about reliance on information and communication technology providers outside the European Economic Area, and about increasingly capable artificial intelligence models that could make cyberattacks more powerful and harder to contain.
The findings were presented to the Financial Stability Table of the EU’s Economic and Financial Committee on September 10 as input from the supervisors. Even so, the report notes that the EU financial system has remained resilient, with banks, insurers and investment funds holding strong fundamentals.
What the warning does, and does not, do
The update is a risk-monitoring document, not a rule and not a finding about any specific network. It names no protocol, sets no deadline and bans nothing. Its practical message is narrower: supervisors and market participants should strengthen their preparedness and keep monitoring risks from emerging technologies, including quantum computing and artificial intelligence.
For the crypto industry, that turns a technical research question into a planning item. A blockchain that relies on widely used public-key cryptography is, by the regulators’ logic, exposed to a future in which a sufficiently advanced quantum machine could break the assumptions that secure transactions and wallets. The warning does not say that day is imminent, and it offers no assessment of which networks are more or less prepared. It simply asks institutions to stop treating post-quantum risk as a distant abstraction.
The practical steps are left deliberately general. The authorities ask for stronger preparedness and continued monitoring rather than prescribing a migration timetable or endorsing any particular post-quantum algorithm. That is consistent with the document’s role as an early-warning signal. It gives compliance and security teams a clear, citable basis for starting the conversation about cryptographic agility, without pretending that the industry has a settled answer today.
Adapted from EU Watchdogs Warn Quantum Computing Could Break Blockchain Encryption.