European financial authorities warned that an advanced quantum computer could undermine cryptography used to secure blockchains, saying the threat could emerge before the technology has a viable commercial application.

The warning from the Joint Committee of the European Supervisory Authorities (ESAs), which includes the European Banking Authority (EBA), European Securities and Markets Authority (ESMA) and European Insurance and Occupational Pensions Authority (EIOPA), brings fresh urgency to a long-running question for bitcoin of whether to freeze or not freeze the BTC in legacy wallets. In the event that quantum computers one day do become capable of breaking bitcoin’s cryptography, roughly 6.9 million bitcoin, worth roughly $586 billion, are currently vulnerable, according to Cryptoquant.

“Threats could materialize earlier than any viable commercial application,” the authorities said in their Autumn 2026 Risk and Vulnerabilities report released Wednesday. An advanced quantum computer “could undermine some cryptography systems widely used to secure communications, transactions, databases and blockchains,” according to the report..

Although the report does not mention timelines for quantum computing becoming commercially viable, a recent IBM report says it will be in use in four years or less.

The Satoshi-era bitcoin held in older, legacy addresses or reused addresses could face greater risk if quantum computing advances. In those cases, the public key may already be visible on the blockchain. A sufficiently powerful quantum computer could use it to derive the private key and take control of the coins.

That does not apply equally to every dormant wallet. Many unspent bitcoin outputs still hide the public key behind a cryptographic hash, leaving them less exposed for now.

Source link