Check whether a Bitcoin address has its public key exposed to a future quantum attack — 100% in your browser.
🔗 Live tool: English · Español
A large quantum computer running Shor's algorithm could derive a private key from a public key — but only if that public key is already visible on the blockchain. Modern unspent addresses only expose a hash of the key, which quantum computers cannot reverse.
Paste an address and the tool tells you which case you're in:
| Verdict | Case |
|---|---|
| 🔴 Exposed by design | Taproot (bc1p…) — the output publishes the public key directly |
| 🟠 Public key exposed | The address has spent funds at some point — signing revealed its key forever |
| 🟢 Protected (for now) | Received but never spent — only a hash is visible |
| ⚪ No activity | Empty / brand-new address |
The check runs entirely client-side: your browser queries the public mempool.space API directly. The address is never sent to, stored on, or seen by any InfoBitcoin server. No sign-up, no tracking of the address.
No build step, no dependencies — each version is a single static HTML file:
git clone https://github.com/optimaquantum/bitcoin-quantum-checker
# then open en/index.html or es/index.html in your browser
- Old P2PK outputs (2009–2011, Satoshi-era) expose the public key too, but they have no standard address form, so they can't be checked by address here.
- A
bc1q/1/3address is judged by whether it ever spent. If the same public key was reused across different address encodings, check each one. - This is an informational tool, not financial or security advice.
- Bitcoin and the quantum threat — full guide (ES)
- BIP-360 — Pay-to-Quantum-Resistant-Hash
Made by InfoBitcoin — Bitcoin market data in Spanish: live dashboard, on-chain whale alerts and a daily market brief.