Is my Bitcoin quantum safe in 2025?
If your coins live at addresses that have never broadcast a transaction, yes — for now. If those addresses have ever spent, the public key is on-chain and the coins are in the quantum-exposed set. No machine today can act on that, but the harvest-now-decrypt-later risk is real.
Bitcoin's signature scheme (ECDSA on secp256k1, and Schnorr in Taproot) is breakable in principle by Shor's algorithm running on a cryptographically relevant quantum computer. The hardware required — roughly 2,000-4,000 fault-tolerant logical qubits — does not exist in 2025. Current systems run hundreds to low thousands of noisy physical qubits.
What matters for individual safety today is the exposure category of your addresses, not raw capability. Never-spent P2PKH/P2WPKH outputs commit only to a hash and are safe. Anything that has ever spent — or any Taproot output by construction — has its public key on-chain and would be the first to fall once capability arrives.
Best practical hygiene in 2025: do not reuse addresses, prefer cold-storage UTXOs that have never spent, and watch the post-quantum BIP discussion. A protocol migration to PQ signatures is the long-term answer.
Related questions
How would I know if quantum became a real threat?
The first visible sign would be opportunistic theft from the largest exposed addresses — early P2PK coinbase outputs, Satoshi-era pubkeys, and reused exchange hot wallets. Any of those moving without explanation would precede any public announcement of capability.
Should I move my coins now?
Only if your current setup reuses addresses or holds long-term funds in addresses that have already spent. Moving to a freshly generated, never-spent P2WPKH address is the simplest hygiene upgrade. Moving for the sake of moving costs fees and adds operational risk for no near-term cryptographic gain.