Europe’s Quantum Warning: Which Bitcoin Wallets Face Greater Risk?
Europe’s financial regulators warned that the threat quantum computers pose to some encryption systems could emerge before the technology is ready for commercial use. The risk is not the same for all Bitcoin wallets; addresses whose public keys are visible on-chain warrant greater attention.
According to CoinDesk, the joint committee of the European Banking Authority, the European Securities and Markets Authority, and the European Insurance and Occupational Pensions Authority said in its 2026 fall risk report, published Wednesday, that some cryptographic systems protecting communications, transactions, databases, and blockchains could be affected by advanced quantum computers.
The warning does not say that a quantum computer capable of breaking the security of Bitcoin exists today. The report also does not give a definite date for when the threat will emerge. Its point is that waiting for widespread commercial use may not be a sufficient benchmark for security preparations.
A wallet’s age alone is not the deciding factor
A significant part of Bitcoin’s risk depends on whether the public key is visible. For older output types whose public keys are directly visible on-chain, as well as reused addresses whose keys have previously been exposed, it may theoretically be possible for a sufficiently powerful quantum computer to derive the private key.
By contrast, in many unspent outputs, the public key remains hidden behind a cryptographic hash. That is why not every wallet that has been inactive for a long time is equally exposed.
According to an estimate cited by CoinDesk and attributed to CryptoQuant, about 6.9 million BTC could be at risk in a scenario where the ability to break Bitcoin’s cryptography is achieved. The report puts the value of this amount at approximately $586 billion. This figure is not a realized loss or a definitive total of funds that can be stolen today; it is an estimate of exposure dependent on future attack capabilities.
Why could Bitcoin’s transition take time?
Moving to quantum-resistant signatures requires broad consensus across the Bitcoin network, unlike updating the software of a single company. Exposed coins may also need to be moved to a suitable new security framework before such an attack becomes possible.
The European Commission’s post-quantum security roadmap aims for member states to begin the transition by the end of 2026, with high-risk use cases protected by 2030. These dates are not a deadline set for Bitcoin or a date for a quantum attack; they are part of a broader security preparedness timeline.