Gavin Andresen Explains Why He Prefers BIP 101 Over BIP 100

Bitcoin Magazine
Gavin Andresen Explains Why He Prefers BIP 101 Over BIP 100
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There have been a few proposals to increase the maximum blocksize in Bitcoin over the past year, but the two plans that are garnering the most attention right now are Jeff Garzik’s BIP 100 and Gavin Andresen’s BIP 101. While Andresen has already implemented his plan in BitcoinXT, Garzik is still working on a formal write-up and the code for BIP 100.

Andresen shared his thoughts on BIP 100 via an interview on Epicenter Bitcoin. Although he did not seem completely dismissive of the proposal, it’s clear that he would prefer to go with his own idea for increasing the blocksize, which would offer more predictability in regard to where the blocksize limit will be in the future.

How BIP 100 Works

When asked directly about BIP 100 by Epicenter Bitcoin co-host Sébastien Couture, Andresen was quick to describe the basic way in which the concept is intended to work:

“Jeff [Garzik]’s proposal is that basically the miners get to decide what the next maximum blocksize should be. There’s kind of a regular vote every — on the order of months.”

Andresen then discussed both BIP 100 and BIP 101 in terms of which proposal would lead to a larger increase in the blocksize limit. The Bitcoin Foundation chief scientist noted that Garzik’s proposal does not come with an immediate increase after it has been implemented, but this does not necessarily mean that it would limit the size of blocks over the short term:

[Garzik] starts with the status quo, so he has no jump-up until the first miner vote. It’s more cautious there. I mean, theoretically, miners could double-up — he has a maximum of 32 megabyte blocks — more quickly. So, if miners wanted to and they all voted for the maximum increase every time, we could be at 32 megabytes more quickly than BIP 101, which would probably be OK if the miners are comfortable with that and they think the network can support it, then OK, so be it.”

Is BIP 100 More Conservative?

Due to the unpredictable nature of Garzik’s BIP 100 proposal, it is difficult to tell if the plan would be more or less conservative than Andresen’s BIP 101. Andresen stated:

Depending on how you look at it, it’s either less conservative or more conservative. It’s probably more conservative.”

If BIP 100 were implemented, it would take a vote from the miners to increase the blocksize limit. In other words, BIP 100 does not increase the blocksize limit by default. It’s also possible that miners could limit the blocksize to a size much smaller than Andresen’s proposed immediate increase to 8 megabytes, which is why some individuals see this proposal as a more conservative approach. On the other hand, miners could vote to increase the maximum blocksize to 32MB in a relatively short period. It is difficult to know which approach would be more conservative without seeing how miners would react to a real-world BIP 100 implementation.

BIP 101 is More Predictable

The key attribute that Andresen likes about his own plan when compared to BIP 100 is that his comes with a predictable increase in the blocksize limit. He explained the importance of this predictability during his Epicenter Bitcoin interview:

I don’t like it as much as BIP 101. I don’t really care what the rule is, but I really like predictable rules. I really like rules that are — I know exactly what the maximum blocksize is going to be on, you know, February 15th, 2022. With BIP 101, we know that. It’s set down there in the spec. We know exactly what it’s going to be, in much the same way that we know what the supply of bitcoin is going to be on that date too — pretty much.

[Bitcoin founder] Satoshi [Nakamoto]’s very predictable money supply algorithm for introducing new bitcoins is kind of what inspires me to propose that we just have this limit be very predictable so people can plan…

You can do some modeling of what I think the demand for transactions is going to be. You might be able to figure out what the fees are likely to be. All those kinds of things are easier to do if you, kind of, fix this rule as opposed to letting it be miner consensus over time.”

The majority of the network hashrate is currently supporting Garzik’s BIP 100 solution via a Coinbase blocksize vote on the network. Having said that, miners are not the only Bitcoin users with a say in the matter. Many bitcoin exchanges, wallet providers, and payment processors, such as Circle and, see value in Andresen’s BIP 101 — but not necessarily the BitcoinXT fork. Coming to consensus on this matter has proven to be next to impossible up to this point, but it’s possible that we could be approaching a breaking point with all of the recent activity in the debate.

Photo Web Summit / Flickr(CC)

The post Gavin Andresen Explains Why He Prefers BIP 101 Over BIP 100 appeared first on Bitcoin Magazine.

Ciphrex’s Eric Lombrozo: There Is No ‘December Deadline’

The long-lasting block-size dispute seems to be inching toward a climax.

A large segment of Bitcoin’s academic and engineering community has been discussing the possibilities and tradeoffs of scaling Bitcoin at the Scaling Bitcoin workshop in Hong Kong this past weekend, while prominent Bitcoin companies such as Coinbase, BitPay, Bitstamp and others have posed a “December deadline” afterward, at which point they will change their code to allow for bigger blocks.

But not according to Ciphrex CEO and Bitcoin Core developer Eric Lombrozo: “Talk of ‘deadlines’ is just that: talk. In the end it is not really up to these companies to impose any such deadline.”

According Lombrozo, whose Ciphrex is the company behind the Bitcoin wallet mSIGNA, the block-size dispute represents a clash of visions. And the only way to reconcile these visions to some degree, he thinks, is through added layers on top of the Bitcoin protocol, such as payment channels and the Lightning Network.

“At one extreme – the ‘big block’ side – we have a system where anyone can transact but few can verify, and at the other we have a system where anyone can verify but few can transact,” Lombrozo explained. “The first is not really much different from exisisting centralized payment systems, and the latter is only well-suited for high-value settlement. Neither extreme is desirable. Bitcoin, in its current form, presents us with this fundamental tradeoff. To get the best of both worlds, or something close to it, will require additional technology layers.”

This assesment is not shared by Google veteran Mike Hearn and former Bitcoin Core developer Gavin Andresen. While not opposing additional layers, Hearn and Andresen maintain that Bitcoin should be allowed to scale “on-chain,” which is why they implemented BIP 101 in Bitcoin XT. BIP 101 is programmed to increase the maximum block size to 8 megabytes if a threshold of 75 percent of mining power accepts the change. Once activated, this limit is set to double every two years for 20 years, ultimately leading to an 8-gigabyte block-size limit.

Lombrozo said he could see himself supporting a block-size limit increase, but only after critical issues with the protocol are fixed to ensure bigger blocks can be rolled out safely. Some of the ideas to do this – such as the “segregated witness” proposal – will be presented in Hong Kong over the next couple of days.

The Ciphrex CEO pointed out that Bitcoin’s base layer technology and basic research and development are underfunded compared to funding on the application level, meaning that improvent has not come as fast as it could have otherwise. But rolling out bigger blocks before proper solutions are implemented is a bad idea, Lombrozo argued.

“Continuing to subsidize transactions while externalizing the costs to the validator nodes that keep Bitcoin secure will not drive greater adoption. What made Bitcoin successful to begin with were the incentives for people to run nodes – to contribute resources to the network … not getting a bunch of retailers to ‘accept bitcoin.’ Externalizing the costs to these nodes is not unlike other industry polluters trying to profit while shirking on the cost of cleanup. And – importantly – it actually works against the dynamic that made Bitcoin successful.

“A block-size increase based on political compromise that disregards serious technical concerns sets a terrible precedent. Appeasing certain interests in this manner may encourage others in the future to try the same tactics. That’s actually one of my biggest concerns regarding any controversial hard fork proposal: Even if the network survives without losing some of its important characteristics, it could provide an opening for future saboteurs.“

Apart from Andresen and Hearn, BIP 101 is supported by several prominent Bitcoin companies, including some that stated they intend to change their code by December, and Bitcoin mining pool Slush Pool. Hearn, moreover, recently alleged that miners will change their code to allow for bigger blocks as well – if no solution is agreed upon after Hong Kong.

Lombrozo, however, squarely dismissed this notion.

“Hearn is known for big talk and bluffs… and misrepresentations,” Lombrozo said. “If you look at the raw statistics, by any metric, Bitcoin XT deployment has been a dismal failure. “Barely anyone is mining in favor of Bitcoin XT; far less than one percent of hashing power. Only an estimated 8 percent of all Bitcoin nodes currently run XT, and this figure has been dropping since its peak around August. The sober view is that most miners and companies are not quite ready to risk it all on a fork of Bitcoin that most of the top contributors believe is a bad idea and that has not been extensively reviewed and tested.“

Lombrozo, instead, believes that the Bitcoin industry will follow the development community, as he believes that would be the only sensible thing to to.

“Who is going to support a BIP 101 Bitcoin?” Lombrozo asked rhetorically. “Where is Hearn going to get all the skilled people to contribute? To whom will these miners and companies turn if anything breaks? The overwhelming majority of the top contributors, even in the Bitcoin XT repository, have made it clear they support neither the repository itself nor Hearn’s tactics.”

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