Over the last months, there have been active debates over the issue of bitcoin block size. While some developers propose to increase the limit, the others are staunchly opposing the idea.
The main argument against raising the limit is that the bitcoin mining will become too expensive. This, in turn, will make the network more centralized, what is against the whole notion of “unregulated ” currency. However, the consensus needs to be found, as the current block size limit of 1MB is likely to create a problem of undercapacity in the near future.
The CEO of the leading bitcoin payment services provider, BitPay, has unveiled his thoughts on this problem issue. In a new blog post on Medium, Stephen Pair proposed his own solution, which he describes as an “adaptive block size limit”.
According to Pair, the block size limit should not be fixed, as it will add a lot of uncertainty for miners. “It is useful for miners to know the limit that is observed by a majority of the mining power and that we have a clear and simple consensus rule for it,” Pair wrote.
A dynamic limit based on a recent median block size, according to the company, is the most appealing solution. The block size will be determined depending on the median size in the last months.
“To determine the block size limit, you compute the median block size over some recent sample of blocks and apply a multiple. For example, you might set the limit to 2x the median block size of the last 2016 blocks,” he noted.
Notably, Ethereum has a similar approach, although instead of a simple moving median it uses a weighted moving average.
In addition to a hard limit, Pair said, there will also be a configurable soft limit. The miners would be able to raise or decrease the soft limit, thus influencing the future direction of the block size limit.
“The choice to use the median, rather than the average, prevents miners from gaming the rule by producing blocks that are artificially inflated with their own transactions. Or, conversely, producing empty blocks,” Pair wrote.
Before proposing the idea to other miners, BitPay will experiment with the approach. “We will perform back testing to analyze what impact various settings might have on historic blocks. We will also analyze behavior under extreme circumstances and critique it from a game theoretic perspective.” Still, it is unknonwn whether the community will accept the proposal.