Eric Lombrozo, a bitcoin developer and CEO of Ciphrex, spoke at the Blockchain Agenda Conference in San Diego, covering possible changes to Bitcoin’s consensus rules.

As BitcoinMagazine reports, Lombrozo started with pointing at the fact that bitcoin’s most valuable feature, decentralisation, leads to the impossibility to decide upon the rules or force them on the network. Since there is no central authority, Lomrozo says, a consensus should be reached, making sure that “everyone still ends up agreeing in the end.”

Lombroso went on to explaining the difference between soft and hard forks and their possible influence on the life of the community. Hard forks have not taken place in Bitcoin protocol since its very creation, and they are exactly what a part of the community currently advocates for in order to increase block size. Lombroso warned:

“Soft forks happen when blocks that used to be valid become invalid according to the new rules… If a majority of miners agree that the new rules are going to be in effect, then that particular chain is going to outgrow the other one and it will become the main chain. In the case of hard forks, this is not the case. We have invalid blocks that become valid under the new rules, and this creates a network fork that can go on forever. So this is a much, much more difficult situation for us to fix.”

The solution proposed by Lombrozo is a thing called “version bits, BIP 9”: a mechanism allowing miners “to signal when they are ready to enforce the new rules” and set up parallel soft forks without knowing which one is going to be activated first. Thus, a warning system gets established, providing old nodes with an opportunity to upgrade as soon as they see new rules are about to get accepted.

The block size debate fuelled by Bitcoin XT’s failure to get universal acceptance has been ongoing for a long time now, with more and more proposals voiced, neither of them yet leading to a consensus.


Maria Rudina