What if quantum computers already broke Bitcoin?

If a sufficiently powerful quantum computer capable of breaking Bitcoin's Elliptic Curve Digital Signature Algorithm (ECDSA) encryption were operational today, the resulting theft would appear as legitimate transactions, making detection nearly impossible until coins were moved. Experts like David Carvalho warn that such a machine could already be active, having compromised wallets whose public keys are exposed on-chain, especially older ones like Satoshi's. While researchers race to implement post-quantum cryptography, most blockchains still rely on 1980s-era encryption, lagging behind traditional finance which is already testing quantum-safe standards approved by NIST. Transitioning Bitcoin requires complex consensus among miners, developers, and users, unlike centralized finance. The primary risk for average holders is a collapse in confidence if the breach becomes public, though experts believe quantum-secure systems are achievable if built proactively.

(Source：Cointelegraph)