Google Quantum AI Estimates Bitcoin Curve Breakable With 500,000 Qubits in 2026

According to Google Quantum AI research published in 2026, breaking Bitcoin's elliptic curve signature algorithm would require approximately 500,000 physical qubits—a significant reduction from earlier estimates. Current quantum machines operate in the 1,000 to 1,500 qubit range, with researchers estimating a viable threat could emerge between 2029 and 2035 depending on error correction progress.

In response, Bitcoin developers proposed BIP-360 in 2026, introducing quantum-resistant address formats starting with bc1z and built around quantum-resistant signature schemes. The proposal was merged into development roadmaps, alongside BIP-361, which outlines how the network could eventually phase out older address types. Wallet providers now face pressure to encourage users to migrate to these newer output types before any potential quantum deadline arrives.