Quantum computers capable of breaking the cryptography securing major digital assets like Bitcoin and Ethereum could emerge within four to seven years, with a significant likelihood by 2033 and possibly as soon as 2030, according to a report from Project Eleven. Such machines could leverage Shor’s algorithm to crack elliptic curve digital signatures in minutes. Google researchers estimate that a device with around 1,200 logical qubits could break Bitcoin signatures in under 90 minutes, suggesting “Q-Day” could arrive by 2032 or earlier. Currently, about one-third of all Bitcoin and over 65% of all Ethereum are held in addresses vulnerable to quantum attacks due to exposed public keys. Blockchains lack mechanisms for reversing fraudulent transactions, making losses irreversible once a hacker obtains a private key. Transitioning to quantum-resistant cryptography is urgent but hampered by slow blockchain governance and technical complexity. Even under ideal conditions, migrating all Bitcoin holdings to quantum-safe addresses would take months. While much of the internet is already adopting post-quantum encryption, the blockchain industry lags behind. Immediate action and migration planning are critical to avoid catastrophic losses once quantum threats materialize.