A bunch of miners started signaling for BIP91 yesterday and a lot of people are feeling more hopeful about the state of Bitcoin as Segwit looks to lock in and activate. In this post, I’m going to update you on the latest developments and what could happen when.
In case you are not familiar, BIP91 is a mechanism by which Segwit (BIP141) can get activated using only 80% of network agreement instead of the 95% required by BIP141. Essentially, BIP91 requires blocks to signal for BIP141 once 80% of a 336-block epoch signals at bit 4. After BIP91 activation, if blocks don’t signal for BIP141, these blocks are orphaned in exactly the same fashion as BIP148 (UASF) is supposed to do. This is a way to front-run BIP148 and remove the possibility of a fork.