SegWit2x Alpha is Out: More than 75 percent of Blocks Signal Support

On June 16, Jeff Garzik announced the Alpha release of SegWit2x. After all, miners who have signed the agreement started to signal for its activation, SegWit2x is nearly instantly backed by more than 75 percent of the hash rate. The activation of SegWit, it seems, is safe – while the hard fork, which is part of the packet, is not.

Jeff Garzik announced in the SegWit2x mailing list the alpha release of SegWit2x on June 16; this is a fork of Bitcoin Core, developed to solve the scaling debate, after an alliance of miners and companies, which represent around 80 percent of the Bitcoin ecosystem, agreed in New York on a path forward.

At the time of writing the client only exists on GitHub; files for auto-installation are not available yet. As Garzik points out, the official branch of the btc1-repository is the release. In it, you find the code for the increase of the base block size to 2MB, as well as the SegWit activation plan BIP91. Now the SegWit2x working group tests the software on testnet. In late July, so goes the plan, it should start. Then the following will happen.

If SegWit reaches a miner support of 80 percent of the hash rate during a period of 336 blocks, the software will activate SegWit 336 blocks later on all SegWit2x nodes. These clients will start to signal the activation on bit1, with which they help old Core Nodes, which are waiting on a threshold of 95 percent, to also activate SegWit.

Not earlier than September 21, but at minimum 12,960 blocks or roughly three months after the SegWit activation, the SegWit2x nodes will automatically increase the block weight limit from 4 to 8MB, equivalent to a hard fork to a 2MB base block size. If the hard

UASF: The Revolt that Will Not Happen

The User-Activated Soft Fork (UASF) wants to enforce SegWit against the will of the miners. After the movement had gained a growing momentum, it had to gulp serious drawbacks in the past weeks. Neither exchanges, miners nor Core developers stand behind it. Is this the end of the self-declared user’s revolt?

Basically, the whole UASF story is about the question who rules Bitcoin; the miners – or the users?

This smoldering conflict started to get attention when Core released the protocol upgrade Segregated Witness. Like any other soft fork, SegWit should have been activated with the support of 95 percent of the miners. Its goal is to increase capacity slightly and to fix the malleable transaction bug which would enable off-chain solutions like the Lightning Network. However, some Core developers agreed with the miners to combine SegWit with a block size-increasing hard fork. Although the miners repeatedly noted that they want this agreement to be enforced, Core and parts of the community did expect SegWit to activate fast.

UASF: How the Users want to Enforce SegWit by Closing their Eyes

SegWit was released in November 2016. Roughly seven months later, in June 2017, SegWit is still not activated. More precisely, it did not even get 40 percent of block signaling by the miners, while the competing capacity increase, Bitcoin Unlimited, is backed by up to 50 percent of miners.

One solution for this stalemate would have been to comply with the agreement and prepare a hard fork to 2MB. This is what the “Silbert Agreement” aims to fulfill. More radical however was the solution Litecoin developer Shaolin Fry proposed; the User-activated Soft Fork (UASF). It roughly goes like this; instead of letting miners activate a soft fork with block signaling, the users do this job by orphaning non-SegWit blocks with