Adam Back says Bitcoin safe from quantum threat for decades; Blockstream researching post‑quantum fixes

Blockstream CEO Adam Back dismissed recent claims that quantum computers pose an imminent risk to Bitcoin, saying current quantum hardware is far from capable of breaking Bitcoin’s secp256k1 signatures. Back and Blockstream estimate a realistic threat — which would require thousands of error‑corrected logical qubits running reliably for days to execute Shor’s algorithm — is likely decades away (Back suggested 20–40 years, if ever). Blockstream researchers are nonetheless working on proposals to make Bitcoin quantum‑resistant. The debate has prompted some large holders to prefer address formats (e.g., SegWit) that avoid reusing public keys, reducing theoretical attack vectors. Critics (including Charles Edwards) urge faster action or an accelerated fork/consensus timeline, while others (including Michael Saylor and some researchers) argue the mid‑term risk is overstated because quantum machines able to break public‑key cryptography would have broad systemic implications beyond crypto. Publicly reported quantum devices still suffer high error rates and lack the stable logical qubits needed (current device counts such as IBM’s noisy qubits or Google’s earlier claims are not equivalent to error‑corrected logical qubits). For traders: immediate quantum‑driven risk to BTC is low — the story is primarily about long‑term protocol planning, developer priorities, and address hygiene (avoid address reuse), rather than near‑term price action.