Overview
- Blockstream CEO Adam Back said current and foreseeable quantum machines are far from breaking Bitcoin and estimated a 20 to 40 year window before a credible threat.
- Back pointed to NIST‑standardized post‑quantum signatures such as SLH‑DSA and said Bitcoin could adopt quantum‑resistant options well before any cryptographically relevant hardware arrives.
- Experts explain that Shor’s algorithm would target exposed elliptic‑curve public keys, making early or reused Bitcoin addresses the primary long‑term risk vector.
- Proposals under discussion include hybrid post‑quantum addresses (BIP‑360), a Taproot option with a hidden PQ branch, a mandatory migration plan (QRAMP), P2TRH to reduce key exposure, and STARK‑based compression to offset larger signatures.
- Researchers warn that post‑quantum signatures are 10–100 times larger and upgrades require broad coordination, while most users are advised to avoid address reuse and stick with modern wallets rather than take immediate action.