A group of Core coders are developing the next stage of bitcoin scaling solution, including the long-awaited 2Mb block size limit. The work has been going on for a year, one of the devs reveals.

The development of the possible third scaling solution, in addition to the Segregated Witness and Lightning Network, had started long ago, according to Luke Dashjr’s comments on Reddit.

“Some of us also agreed to work on another hardfork proposal including a 2 MB "no wallet changes necessary" block size bump, which we've been making progress on over the past year, including even after conclusion of the original agreement (there is currently a testnet for an incomplete version running).”

The “no wallet changes” part sounds rather confusing, which made users wonder if the proposed update is really a hard fork and how it would fit previous soft fork solutions such as SegWit. Dashjr had to explain that the hard fork “would enable pre-segwit wallet code to take advantage of the higher capacity as well. But even then, the light-node part of that wallet software will need to be updated.”

He clarified that the project aims to increase the maximum block size limit to 2 Mb, while in fact helping to decrease the actual and average block size. This is necessary to reduce the Initial Block Download (IBD) cost and improve the block latency.

Besides scaling and allegedly a more secure way of hard fork implementation, the proposal promises “lots of useful improvements” including the new Merkle tree algorithm that closes some existing vulnerabilities.

The team’s work has not been advertised much among the community, although it was by no means a secret: it was referred to as a hybrid “part-softfork – half-hardfork” project as early as February 2016, even prior to the Hong-Kong scaling consensus between miners and developers.

Speaking to CoinDesk in September, another Core developer, Matt Corallo, mentioned that some work on the solution was going on within the team:

“A number of people working on Bitcoin Core think we should have an idea of how [a hard fork] should look.”

According to 21.co, as of 07:00 UTC the latest version of Bitcoin Core 0.13.1, which includes the activation of the SegWit code, was supported by 1873 nodes, or 35.4% of the network. The full SegWit activation will come in power after receiving support of 95% of miners and generating 2016 blocks during a retarget period.

Elena Platonova, Svetlana Nosova