Brexit and “BUxit”

One of the proposals of scaling Bitcoin is known under the name of “Bitcoin Unlimited” (BU).

The recently opened website has this to say about the conditions for activating BU:

Bitcoin Unlimited has no script to create a hard fork. It just gives the stakeholders this option. How they use it is up to them. A possible way to hard fork to bigger blocks was laid out by the Mining Pool ViaBTC which suggests an activation plan at a certain block height after an agreement of at least 75 percent of the hashrate.

It’s important to note that this is just one option. Bitcoin Unlimited gives the whole ecosystem the flexibility to commonly find a reliable and secure way to increase the maximium (sic) block size limit from 1MB. Come together, discuss, decide, do.

While the conditions for activating are unclear, this is clearly a hard fork. Hard forks are changes in the network that are not backwards compatible. Nodes that run Bitcoin Core software will see all blocks over a size of 1 MB as invalid. This will split the blockchain into two branches.

If you are going to split the blockchain anyway, why wait for 75% of the signal?

Why not just go ahead right now?

I call this option “BUxit”, shortened from “BU exit” and obviously inspired by “Brexit”.

The point becomes very clear by the comparison to Brexit. The United Kingdom leaving does not mean taking over the EU. It means their ability to decide on their own about their future policy.

In contrast, the BU proposal wants to stay in Bitcoin and change the way Bitcoin works. That is not “BUxit” as I coin the term here.

It is open to debate if a BUxit is a good idea. The purpose of this post is not to give an opinion about that. It is only to introduce the term and the idea that this is one possible solution, which is distinct from a complete BU takeover.

Brexit was formally triggered by a notice to the EU in March 2017. This leads to a two-year period of negotiations. The United Kingdom will cease to be a Member State after these two years. This is based on the procedure for withdrawal in Article 50 of the Treaty on European Union.

Obviously, there is no regulated procedure for the withdrawal of a minority position from the Bitcoin project. But there is common sense.

Common sense should require at the least a couple of months in prior notice.

Common sense should require a good faith effort of everyone involved to agree about the issues that need to be decided in the event of a BUxit.

The most important issue is which project gets to call itself “Bitcoin”. There is considerable brand value attached to that name.

Another issue is how to deal with the potential for replay attacks.

If these issues can get resolved, it may be good for everyone involved if the BU camp just leaves instead of trying to take over the whole project.