BIP-360: Pay-to-Merkle-Root (P2MR)

BIP-360 is a draft Bitcoin Improvement Proposal: a consensus-layer soft-fork specification aimed at reducing quantum exposure. It was introduced as P2QRH ("Pay to Quantum Resistant Hash") and later renamed to its current title, Pay-to-Merkle-Root (P2MR).

The proposal specifies an output that behaves like Taproot but removes the key-path spend, so that no spendable elliptic-curve public key is revealed on-chain until the moment of spending. It commits directly to the Merkle root of a script tree rather than to a tweaked public key. The goal is to protect against "long exposure" attacks against funds that are simply sitting at an address.

The authors are explicit about scope. P2MR does not by itself solve short-term mempool exposure, and the choice of which post-quantum signature algorithm to use is deliberately deferred to a separate future BIP, so the output type can be debated independently of the algorithm question.

As of 2026 the proposal remains in Draft status and is not scheduled for activation.