BIP91 vs August 1st

BIP91 reaches 80.5% network support
19 July

Is the first decentralized peer-to-peer payment network that is powered by its users with no central authority or middlemen

Bitcoin community has lost sleep for a couple of months over SegWit2x and the Bitcoin User Activated Soft Fork (UASF) which is to be activated on August the 1st.

Now, while a significant part of users is concerned about a possible hardfork in the Bitcoin network, the miners begin to vote for BIP91 proposal as it is considered to have good chances to become an unexpected compromise solution in the debate on consensus.

In fact, it is the only proposal actively preventing a Bitcoin chain split right now. The bigger question is whether or not BIP91 can gain enough traction in the coming days.


Distributed database that is used to maintain a continuously growing list of records, called blocks

The support for BIP91 is certainly on the rise. Various mining pools are actively signaling support for this solution right now: 80.5% of blocks mined over the past 24 hours support this solution. It goes without saying that scaling Bitcoin without a chain split should be in everybody’s best interest.

Bitcoin voting chart on Bitcoin voting chart on

Why BIP91?

The implementation of softfork in the Bitcoin network requires miners to include a special signal bit into the blocks, thereby showing their willingness to adopt the new rules. The original version of Segwit2x required the inclusion of the fourth signal bit (bit 4) in order to support BIP141, and that's when the conflict appeared, because the BIP141 code had been already written to respond to the first signal bit (bit 1).

To bypass this conflict, BIP91 uses an additional bit signaling the mandatory acceptance of the original first signal bit. Accordingly, there is no need to change the already existing SegWit activation logic.

Thus, if BIP91 to be activated before July 31th, it will replace BIP148, which also assumes the activation of SegWit, but carries the risk of splitting the Bitcoin network into several blockchains.

However, if one big mining pool stops signaling it, BIP91 will be back below 80% pretty quickly. Given that some pools like to play games with the rest of the Bitcoin community, BIP91 may never happen in the end. After all, there are less than two weeks to see it get locked in, which means time is of the essence.

Ethereum network is still unstable

Byzantium had executed on Monday, but developers aren't ready to call the software transition complete
18 October

Organizations and developers are better off refraining from launching large projects until the Ethereum network is fully stable after the recent Byzantium update. This is said by the Gavin Wood, Parity Technologies head and reported by the Coindesk.

Since new versions of the software were released just days before the fork, much of the network has not yet been updated. So, at the time of press, slightly more than 25% of Parity customers updated, in Geth this indicator is slightly higher - about 59%. So, in total, the update was made about 45% of the network.

Another aspect that should also be taken into account is the short time for testing. In particular, the developers recalled previous versions of the software, discovering critical errors that could make the network vulnerable to DoS attacks or lead to incompatibility between nodes and, as a consequence, network sharing.

Therefore, the question of how safe the network is at the moment is fully justified and, taking into account what has been said above, remains open. This is exactly what Gavin Wood warned, recommending at this stage to refrain from launching large-scale projects.

In addition to the nodes that have yet to update, there is also a possibility that in the current Byzantium software there may be bugs that endanger the security of the Ethereum network. The most dangerous among them is a bug of consensus, in which nodes can not communicate. Its result can be the separation of the block-man into several incompatible chains.

As far as is known, at the moment developers are conducting extensive tests, trying to detect such bugs before they are active. As Gavin Wood says, if the network does contain such a bug, it will take several days to prove itself.

I don't think anyone believed the network was going to self-combust on block 4,370,000.

Gavin Wood
Head, Parity Technologies

The head of Parity Technologies is also convinced that if problems are discovered, the Ethereum development team will quickly release new updates designed to prevent any harm to the platform.