Bcoin and Extension Blocks

This is a supplement for my Patreon Episode released 4/4/2017 that can be found here.

Timeline Begins

Yesterday I noticed some tweets about strange blocks and Samson Mow started tweeting about a secret Bitmain project. I started investigating and this is what I found.

Bcoin Extension Blocks

In January the Bitcoin Development Grant gave out funding to 3 projects, Bitcoin Classic, Bitcoin Unlimited and Bcoin. There was some controversy at the time, as many companies either pulled their names off a list of supporters or refused to sign in the first place. They saw it at the time as very politically motivated and not healthy for bitcoin.

Bitmain’s BTC.com Uses Bcoin for Mining

Several months ago, Bitmain acquired Blocktrail and used it on BTC.com. Then in March BTC.com’s pool mined it’s first block with a bcoin miner. At the time where was congratulations, because it was seen as diversity and bcoin was a segwit ready implementation.
Secret Development

We know now that over the last few months, after their funding from the political Bitcoin Development Grant backed by Jihan and Ver, bcoin developers were working on this Extension Block project.
What are Extension Blocks

Extension Blocks (EB) are blocks of data like a real block that are attached to a real block through the header and coinbase transaction that creates new bitcoins. It looks something like this block that was mined on April 1st, seemingly as an April Fool’s joke.

Anyway, EB create a second layer that is controlled by the miners, that insulate real blocks from other layer two things like Lightning Network. This essentially gives miners control over layer two.

Since miners don’t want to scale, hate layer two, and don’t want more than 1MB blocks, this is very very dangerous. They want to control layer 2.
Here is a breakdown of EB from a few weeks ago.

Fishy Release

Bcoin avoided the standard release procedure of creating a BIP or first asking other devs for peer review. Instead, they approached media under a nondisclosure type agreement and released a blog post. They said, “don’t talk to anyone close to Core.” Extremely, fishy. Miners were aware, too, because of the April Fool’s joke.

Jihan was also prepared, because not more than 2 hours after the blog post release, Jihan started tweeting about supporting Extension Blocks. The paid shills of BU/Ver/Jihan started coming out in support of EB, too. Just a few hours into this out-of-the-blue announcement, things were getting very obvious that it was a hostile takeover attempt.


The Hard Fork debate is over, but not completely gone right off the bat. That’s a big win for bitcoin.

Question every word the Bitcoin Cabal says, writes, etc. Nothing they say can be trusted. Users can stop this hostile group by throwing them out of the community.

Let’s show our unity, as the 90%+ of nodes for Segwit shows.

As a Miner Activated Soft Fork (MASF) it is placed directly in competition with SW’s UASF. It has to be activated by a majority of miners, which might be the case here, and be accepted by economic nodes like exchanges and stuff. That will not happen. Bottom line, this is another delay.

It’s not a replacement for BU yet, but it will be. First, it will be sold as BU + EB and rejected vigorously. The cabal will need to drop BU. Debate will be filled with wild claims from MASF side, like it has miner support, and lies will be thick as shit everywhere.

As a Soft Fork, discussion might not be moderated in r/bitcoin so watch out for crazy sock puppet accounts.

Let me know what you think.

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