European financial supervisors warn that quantum threats may arrive early
The EU financial supervisors’ autumn risk report warned that quantum threats to blockchain cryptography could precede viable commercial applications. It raised a financial-system security concern without imposing a Bitcoin-specific migration deadline.
On September 23, 2026, the Joint Committee of the European Banking Authority, ESMA and EIOPA issued its autumn update on risks and vulnerabilities. The report warned that quantum threats to cryptography, including blockchain systems, could materialize before viable commercial quantum applications.
The Bitcoin connection is an inference from its reliance on elliptic-curve signatures: a sufficiently capable quantum computer would create risks for cryptographic authorization. The report’s warning, however, was about financial-system dependencies and cryptographic migration more broadly. It did not quantify vulnerable Bitcoin holdings or announce a new rule governing Bitcoin transactions.
The report also pointed to Europe’s existing post-quantum transition work. The end-of-2026 objective concerned member states adopting migration strategies, not a deadline for Bitcoin to replace its signature system. September’s contribution was a formal warning from EU financial supervisors that defensive planning should account for a threat timetable different from commercial adoption.