BIP 8 (Soft Fork Activation)

Bitcoin Improvement Proposal (BIP) 8 proposed an alternative method to BIP 9 for activating soft forks. BIP 8 closely resembles BIP 9, with a few important changes, which are intended to improve upon BIP 9’s perceived downsides.

➤ Learn more about how BIP 9 and BIP 8 work.

First, BIP 8 uses block height, rather than timestamps to determine the start time and duration of the signalling period. This small change has relatively little impact on the normal activation process, but it removes the possibility of a precipitous drop in hash rate derailing an upgrade activation.

Secondly, BIP 8 implements an optional flag which, if true, forces the activation of the upgrade even if the threshold for miner support, usually 95%, is not met before the signalling period ends. BIP 8 frames hash rate signalling as a method for accelerating activation for overwhelmingly popular upgrades, rather than as the main mechanism for activation.