The fixation of the proposal to improve Bitcoin BIP 91 has officially taken place on the night of Friday, July 21, when more than 90% of the network hashrate showed support of this decision as reported by Bitcoin Magazine.
The next step is to activate Segregated Witness (SegWit). In addition, theoretically there is no need to activate BIP 148 (UASF), and the key date, August 1, also loses its relevance.
However, as the observers noted, the activation of SegWit still can not be considered as guaranteed.
We remind, that BIP 91 is a modified version of the BTC1 plan (SegWit2x), which supported a number of bitcoin-companies and mining pools, in May, this year they signed the corresponding agreement in New York. In addition, BIP 91 is compatible with BIP 148 (UASF) – another proposal to activate the original SegWit offer, described in due time in BIP 141.
To fix BIP 91, it was necessary for the miners to signal support for this solution through the fourth signal bit (bit 4) during the strictly determined time period (56 hours). And provided that 269 of the last 336 blocks include bit 4, BIP 91 fixation takes place. That's exactly what happened on the Friday night.
However, now when the second activation period of the BIP 91 has come, the miners have to start using the first signal bit (bit 1). Blocks without such bit will be rejected, i.e., they will not get into the general blockchain.
Favorable scenario
Provided that most of the miners support BIP 91, after a certain time their capacity should begin to control the longest valid chain, which all the nodes will accept. And since this chain consists of blocks, signalling support only for SegWit, accordingly, the SegWit protocol itself will be activated.
In this case, the fixation of the user-activated softfork (BIP 148) should take place in mid-August, and two weeks after the so-called “grace period”, the activation of SegWit should take place.
Unfavorable scenario
Despite the fact that more than 80% of the miners in the last few days voted for the activation of BIP 91, there are still no guarantees that the proposal will be activated. As it was mentioned above, starting from the new activation period, they should go to bit 1, but at the moment the number of the miners signaling the support of BIP 91 on the first bit is much less than the required threshold – less than 50%.
And since the activation of BIP 91 is possible only due to the hash ate of miners, this means that they can theoretically continue finding blocks with bit 4. In fact, this will mean quitting BIP 91 and refusing the support of SegWit. Despite the fact that this is associated with certain reputational losses, the miners, if they are the majority, continue controling the longest valid chain.
Moreover, the remaining miners, who continue voting for BIP 91 through bit 1, may be subsequently divided into a separate chain. They will consider it to be valid, but the rest of the network will completely ignore them.
Thus, successfully fixing BIP 91 through the fourth signal bit (bit 4), most of the miners, including the pools that previously rejected the SegWit implementation, essentially made nothing more than a statement of intent. Time will show how much these statements are in line with their actual intentions.
The fact that some miners, voting for BIP 91, hid their true intentions, experts warned about this a few days ago. So, according to Oleg Andreev from Chain, we can talk about actual "sabotage."
He does not give a very optimistic forecast for the future development of the situation: a false alarm in support of BIP 91 will lead to a chaotic reorganization of the network, the miners themselves will leave BIP 91, the fault will be assigned to UASF supporters, the current status quo, i.e. the absence of any consensus will continue.
The near future will show, how much such a forecast is correct. Meanwhile, the community reacts positively to the fixation of BIP 91, which is confirmed by the rapid growth of bitcoin prices: on Friday night, the weighted average rate of the first cryptocurrency, according to Coinmarketcap, reached $ 2900, and at the time of publication is $2,787.