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BITCOIN AND QUANTUM COMPUTERS

Is quantum a threat to your Bitcoin?

Not today. But some coins are far more exposed than others, and the fix takes years to roll out. Here is what is at risk, how to check your own address type, and what to do now.

LIVE · QUANTUM VS BITCOIN TRACKER

Physical qubits0.24%

1,180 physical qubits today (Atom Computing Second-generation neutral-atom system) of under 500,000 needed

Error-corrected (logical) qubits4.0%

48 logical qubits today (Quantinuum Helios) of 1,200 needed

Target: what it would take to break one Bitcoin or Ethereum key (secp256k1), per Babbush et al. 2026. Physical qubits are the raw, noisy hardware; logical qubits are error-corrected ones built from many physical qubits. The bars are linear, so a thin bar really is that far away.

Updated from QuantumUnzipped’s tracker. See the full tracker, charts and every source →

How much bitcoin is exposed?

A quantum computer attacks a public key. These coins already have theirs on the blockchain.

6.9 millionBitcoin with a public key already on-chainAll script types: P2PK, reused addresses, Taproot and others. "At the time of writing", from Google BigQuery’s public Bitcoin data. Babbush et al., Google Quantum AI (arXiv 2603.28846 v2), April 15, 2026.
1.7 millionBitcoin in old pay-to-public-key (P2PK) outputs"A little over 1.7 million", nearly 9% of all bitcoin. Mostly 2009–2010 mining rewards. Babbush et al., Google Quantum AI (arXiv 2603.28846 v2), April 15, 2026.
1 millionSatoshi-era coins thought to be Satoshi’sSergio Lerner’s "by eye" estimate from the early-block mining pattern. Never moved; held in P2PK outputs, so part of the 1.7 million above. Sergio Demian Lerner, Bitslog, April 17, 2013.

Is my address type at risk?

This check reads only the address format, in your browser. It does not look up balances or history, and nothing you type leaves this page.

Where the fix stands

Draft BIP

BIP-360 "Pay to Merkle Root" (P2MR, formerly P2QRH): a new output type that hides keys until spent. It adds no post-quantum signatures itself; those are left to a later proposal. Read BIP-360.

A full fix needs three steps: a new output type that hides keys (BIP-360), post-quantum signatures (NIST standardised ML-DSA and SLH-DSA in August 2024), and every holder moving their coins. Each step needs community agreement and a soft fork.

What to do now

  1. Never reuse an address. Let your wallet give you a new one for every payment.
  2. Don’t leave change on a spent-from address. Most modern wallets already send change to a fresh address.
  3. For long-term savings, prefer a never-spent-from bc1q address over Taproot (bc1p), which shows its key on-chain.
  4. Watch, don’t panic. There is no quantum attack today. Follow the live tracker and BIP-360. If you want a wallet that makes this easy, see our wallet guide.

Questions

Can a quantum computer steal my bitcoin today?

No. Today’s largest machines are hundreds of times too small, and their error-corrected qubits are fewer still. The question is how many years, and whether Bitcoin upgrades first.

Which address types are exposed?

Pay-to-public-key (P2PK) outputs and Taproot (bc1p) addresses show a public key on-chain from the start. Legacy (1…), script (3…) and native SegWit (bc1q…) addresses hide it until you spend, so they are exposed only if you reuse them after spending.

What should I do now?

Use a fresh receiving address each time, do not leave coins on an address you have already spent from, and keep long-term savings on a never-spent-from bc1q address. Do not panic-move coins: there is no quantum attack today.

What is BIP-360?

A draft Bitcoin proposal, now called Pay to Merkle Root (P2MR), for a new output type that keeps keys hidden until spent. It does not add post-quantum signatures itself; those would come in a later proposal and a soft fork.

Will Satoshi’s coins be stolen?

They sit in old P2PK outputs whose public keys are visible, so they are among the first coins a capable quantum computer could target. Whether Bitcoin should freeze such coins in advance is an open, contested debate.