delvingbitcoin

BIP 8.5: Flag day activation based on nLockTime signaling

BIP 8.5: Flag day activation based on nLockTime signaling

Original Postby 40000bytes

Posted on: August 19, 2024 04:25 UTC

This document introduces an innovative method for activating soft forks within the Bitcoin network, proposing a shift away from the contentious BIP 8 and BIP 9 activation mechanisms.

It outlines a structured process that leverages nLockTime signaling combined with a flag day activation to streamline the adoption of new protocols. The essence of this proposal is to allocate specific numbers—either arbitrary or based on existing BIP identifiers—to various soft fork proposals. Users would then signal their support for a given proposal by broadcasting transactions with the chosen number encoded in the nLockTime field. This approach enables miners to demonstrate their readiness to support a soft fork by including such transactions in a block.

The proposal emphasizes a community-driven analysis phase lasting three months, during which the volume and distribution of transactions supporting different soft forks are evaluated. This preparatory period culminates in a flag day, a predetermined date on which the network collectively activates the agreed-upon soft fork. This method aims to mitigate the divisiveness observed with previous activation mechanisms by fostering a more transparent and consensual decision-making process.

Furthermore, the document addresses potential concerns regarding transaction inclusion. If a user's transaction, designated to signal support for a soft fork, remains unconfirmed for an extended period, the protocol allows for the submission of a replacement transaction. This substitute would spend the same inputs but could utilize a different nLockTime, thereby enabling users to adjust their support signals based on changing circumstances or preferences. To facilitate the proposed activation mechanism, reference implementations for both the activation process and adjustments to relay and mining behaviors have been provided, accessible here for activation and here for exclusion in relay or mining. This structured approach seeks to harmonize the activation of soft forks, ensuring a smoother transition to upgraded protocols within the Bitcoin network.