Can Bitcoin be cracked by quantum computers? If 'upgrading to quantum level' means Bitcoin has completed a quantum-resistant algorithm hard/soft fork and all users have migrated their assets to new addresses: quantum computers cannot crack it. If 'upgrading to quantum level' means Bitcoin has merely 'enhanced' or 'optimized parameters' for its encryption algorithm under the existing architecture but still relies on elliptic curves: it can be cracked. As long as the foundational algorithm remains unchanged, Shor's algorithm is its nemesis. Current reality: Quantum computers (as of 2025) are still far from reaching the scale needed to crack Bitcoin (requires logical qubits, not physical qubits). The cryptography community and Bitcoin core developers are actively researching quantum-resistant migration solutions (e.g., proposals like BIP-360). Whether Bitcoin can complete its quantum-resistant upgrade before the arrival of quantum supremacy is the real suspense in this game. @cz_binance