Quantum Threat Crushed: P2MR Bitcoin Upgrade Just Landed

Bitcoin’s P2MR upgrade merged into the BIP repository. Protection from quantum computers is now a reality. Your funds just got a quantum-resistant security layer.

Bitcoin just became quantum-resistant. The Pay-to-Merkle-Root (P2MR) protocol was merged into Bitcoin’s official repository. This happened recently, according to Anduro BTC’s announcement on X.

The upgrade addresses quantum computer threats. Cryptographically Relevant Quantum Computers could break Bitcoin’s cryptography. Not anymore.

P2MR removes Taproot’s vulnerable key-path spend. It preserves Tapscript compatibility though. The new output type offers quantum protection, as outlined in BIP 360’s technical documentation.

Bitcoin just made a meaningful step toward future quantum resistance 💪

An updated version of BIP 360 has just been merged into the official Bitcoin BIP GitHub repository.

The update introduces Pay-to-Merkle-Root (P2MR), a proposed new output type that omits Taproot’s…

— Anduro (@andurobtc) February 11, 2026

Source: Andurobtc

Hunter Beast, Ethan Heilman, and Isabel Foxen Duke authored the proposal. Duke joined to make technical details accessible. Average users can now understand quantum threats.

Your Bitcoin Gets Military-Grade Protection

The Commercial National Security Algorithm Suite mandated quantum-resistant upgrades by 2030. Bitcoin beat that deadline. NIST plans to ban Elliptic Curve Cryptography by 2035.

P2MR protects against “long exposure attacks.” These occur when public keys stay exposed. Quantum computers need time to crack them. Short exposure attacks remain theoretical.

According to Anduro BTC on X, the change is opt-in. Existing Taproot outputs remain unaffected. It’s a soft fork implementation.

The upgrade uses SegWit version 2. P2MR addresses start with “bc1z” on mainnet. Example: bc1zzmv50jjgxxhww6ve4g5zpewrkjqhr06fyujpm20tuezdlxmfphcqfc80ve.

Bitcoin developers finally addressed quantum criticism. Some claimed they ignored the threat. This proves otherwise.

P2MR witnesses are smaller than P2TR script paths. No internal key revelation required. Privacy improves slightly. Transaction sizes decrease compared to equivalent Taproot spends.

The protocol commits to Merkle tree roots. It skips the internal key entirely. Script trees remain functional, though.

Post-Quantum Signatures Coming Next?

Anduro BTC tweeted that this provides a foundation for post-quantum signatures. Future upgrades could add complete protection. Short exposure attacks would become impossible.

P2MR reuses existing Bitcoin code. Wallet integration stays simple. Exchanges can adapt quickly. The BIP 360 specification maintains backward compatibility.

Pay-to-Public-Key-Hash outputs were already quantum-resistant. P2MR adds script tree support. Tapscript features remain available.

Long exposure attacks target exposed blockchain data. Public keys sitting on-chain become vulnerable. P2MR solves this problem.

The upgrade requires OP_SUCCESSx opcode support. Post-quantum OP_CHECKSIG opcodes need this. P2WSH outputs lack this capability.

Bitcoin addresses starting with “bc1p” remain vulnerable. Reused addresses expose public keys. P2MR addresses starting “bc1z” offer protection.

Transaction fees for P2MR exceed P2TR key-path spends. Witnesses include leaf scripts and Merkle paths. Control blocks add extra data. The security tradeoff seems worth it.

Anduro BTC noted on X that every Bitcoin contributor helped. Review processes took time. Feedback improved the proposal significantly. The merged code proves Bitcoin’s quantum readiness.

CNSA 2.0 mandates full upgrades by 2033. Operating systems must use post-quantum schemes. Bitcoin positioned itself ahead.