Google's Willow, with 105 physical qubits, cannot break a private key from a public key in Bitcoin, as 2000–3000 logical qubits are needed for Shor's algorithm. This makes such an attack impossible with current technology.
A quantum computer with 3000 logical qubits could use Shor's algorithm to derive a private key from a public key in hours to days, rendering Bitcoin's elliptic curve cryptography (secp256k1) vulnerable. This threatens addresses with exposed public keys.
Modern Bitcoin wallets (HD wallets) counter this by generating a new address for each transaction. The public key remains hidden until the address is used, protecting unused addresses from quantum attacks.
Guessing a 24-word seed phrase (256 bits of entropy) with a quantum computer is nearly impossible. Grover's algorithm reduces the search to ~2^128 attempts, but even with 3000 qubits, this would take billions of years. Neither Willow nor a more powerful quantum computer has a practical chance of success.
Conclusion: Bitcoin is secure against current quantum computers.
