The Google Quantum AI whitepaper published in March 2026 has shed light on the vulnerability of certain Bitcoin addresses to quantum attacks. The study identified approximately 6.9 million coins, about one-third of the total supply, that are exposed due to permanently visible public keys.
The researchers used optimized quantum circuits to demonstrate that breaking elliptic curve cryptography could be achieved with fewer than 500,000 physical qubits, a significant reduction from previous estimates. This has sparked concerns and discussions within the Bitcoin community about migration and governance.