Venomous Reddit comments and division may come to mind when you hear the words “blocksize debate” (at least if you've been following along). Yet in the latest episode of Epicenter Bitcoin proof-of-work inventor Adam Back argued technical consensus is still on the table.

Rewinding a bit, Back noted that decentralization has been difficult to preserve in the past. “PayPal started off as a bearer asset cash protocol, so something much more Bitcoin-like on palm pilots,” he said. “But migrated, presumably for practical reasons, into central web servers,” he said.

Back emphasized:

We need to hold on to the decentralized nature of Bitcoin and its permissionless properties. Everyone wants to scale bitcoin. It's really complicated and there is no silver bullet. What we're trying to figure out is, what is the safe, pragmatic way to do this.

A hardfork is neither, according to Back, who is also the co-founder and President of Blockstream and has been a loud voice in the blocksize debate. Why? Epicenter co-host Brian Crain asked what Back thought of a decision-making process whereby people choose which software to run. This is what Bitcoin XT does. If 75% of miners switch over by January, it will result in a hardfork.

But Back pointed to BIP 66, which made uncontroversial changes to the protocol. When it finally triggered, it caused a temporary network fork, known informally as “4th of July fork.”  The event demonstrates that even a change that everyone agrees with can still go wrong. Hardforks are riskier.

Back argued that the BIP process, where developers talk over proposed technical changes and come to consensus over time, is preferable.

He pointed to the variety of recent BIPs that tackle the blocksize. “There tends to be black and white thinking that there's some Bitcoin developers that want 1 MB blocks only, and then some that want to increase it. But this is a mischaracterization,” he said.

Back further explained why decentralization isn't necessarily easy to safeguard.

“Decentralization is at an ebb right now,” he said, if you look at some of the available metrics, such as the small number of mining pools, and the number of ASIC manufacturers, which has decreased, and the number of full nodes, which has, well, decreased. The last one is a bigger deal than people expect, Back stressed. (Coincidentally, Paul Sztorc, the chief scientist of prediction market Truthcoin, took on this topic in a recent blog post.)

Benevolent dictator vs. BIP

Another interesting aspect of Bitcoin XT, is the “benevolent dictator” model. Developer Mike Hearn will make the “final call” in the case of stalemates, and former lead developer Gavin Andresen argued that he often did the same to settle disputes. Some people like this option because, so the argument goes, there are sure to be other technical battles down the road.

But Back argued that consensus is possible, and suggested that the BIP process is good enough. Consensus has been achieved in the past. “I do think that there are plenty prior examples about complicated technical discussions that reached a consensus and got implemented,” he said.

And it makes sense to do the same here, Back said, “Otherwise we're at risk of people jumping on the first simple proposal that has been put out there that's been articulated, or maybe articulated the most widely in the non-technical community, at the expense of not taking benefit of much more effective proposals.”

The Scaling Bitcoin workshop, going on this weekend in Montreal (live stream here), may be a good gathering point, he said, as it includes a variety of stakeholders, including merchants, miners, and academic sponsors.

Given all the technical details, it's not easy to understand the debate, Back said. “Even the people who are writing the code are still learning new things about consensus limits and scalability limits.”


About Epicenter Bitcoin

Epicenter Bitcoin is a podcast about the technologies, projects & startups driving decentralization and the global cryptocurrency revolution. Every week hosts Brian Fabian Crain and Sebastien Couture talk to some of the most influential people in the cryptocurrency space about their projects and get their perspectives on recent events. Their guests, who range from entrepreneurs to academics, to industry experts, join the conversation from different locations around the globe, which gives EB a truly international scope.

You can watch live Google Hangouts every week on YouTube and listen to the audio version on SoundCloud and iTunes.