A new proposal in the #Bitcoin improvement process — Pay-to-Merkle-Root (BIP-0360) — has been merged into the official BIP repository, but it is only a documented draft, not a network upgrade or emergency patch. No activation timeline exists, no nodes need to update, and publication does not imply consensus or eventual adoption.

P2MR defines a new output type similar to Taproot but deliberately removes the key-path spending option. Instead, every spend must use the script path and reveal a Merkle proof. This increases transaction size and fees on purpose, but reduces long-term exposure to quantum attacks by eliminating always-visible public keys that could be targeted by future quantum computers.

The proposal frames quantum risk in two ways: long-exposure attacks on keys already visible on-chain, and short-exposure attacks during the brief window when a transaction is unconfirmed. P2MR mainly addresses the long-exposure scenario, while broader post-quantum signature schemes would be needed to defend against short-exposure threats.

The core message is about early preparation. Because $BTC Bitcoin upgrades require years of specification, review, debate, wallet support, and user migration, developers are exploring low-risk transition tools well in advance of any confirmed quantum timeline. If ever activated through a soft fork, P2MR would be opt-in, with gradual adoption driven by users and institutions willing to trade higher fees and lower privacy for reduced long-term quantum risk.