Bitcoin Core Proposes Unlimited OP-Return Size Amid Community Debate

On June 10, the Bitcoin Core development community released a statement titled "Bitcoin Core Development and Transaction Relay Policy," which has sparked significant debate within the community. The statement outlines plans to implement a built-in transaction relay within the Bitcoin Core software, a move that has raised concerns and ignited discussions.

The controversy centers around the Bitcoin network's handling of script transactions. Two years ago, scripts began embedding content into the Bitcoin blockchain's OP-Return area, effectively bypassing the block size limit. This practice, known as a "card bug," has divided the community into two factions: the mainstream right, represented by the Bitcoin Core team, and the far right, led by figures like Luke. The far right faction introduced a garbage filter in the second-ranked client, Knots, to treat these script transactions as junk and refuse to mine them. This move caused an Ordi crash but was seen as a necessary measure to maintain the integrity of the blockchain.

The Core team, however, has a different perspective. They believe that since these scripts have already found a way onto the chain, it is better to legitimize them rather than continue to block them. This stance has led to a new pull request proposing to change the OP-Return size from 80KB to unlimited, effectively removing restrictions on scripts and allowing them to be included on-chain openly. This move is seen as an additional subsidy to miners, potentially enhancing the security of the Bitcoin network.

The transaction relay policy aims to address two main issues: preventing DoS attacks by filtering out spam 0-fee transactions and speeding up transaction block propagation. This relay system is voluntary, allowing users to choose whether to send their transactions through it. The Core team argues that this policy helps prevent large miners from gaining unfair advantages and ensures a more secure and efficient network.

The debate centers around the definition of spam transactions. The far right believes that data embedding is a form of spam and should be eliminated, while the mainstream right argues that only purely DoS attacks should be filtered out. The Core team's mild spam filtering rules are seen as a compromise that benefits both the security and lack of transaction censorship, which are core attributes of Bitcoin.

Critics argue that this move is a concession to miners, prioritizing their income over user interests. However, supporters, including the author, contend that Op_Return users are also Bitcoin users and that the network should evolve with the times. The author supports the Core team's proposal, stating that Bitcoin's electronic gold should allow for data storage as a side job, much like physical gold can be used to carve records.

The author concludes by emphasizing the importance of Bitcoin's security and lack of transaction censorship. The Core team's proposal, while controversial, is seen as a step towards maintaining these attributes while adapting to the changing technological landscape. The debate highlights the ongoing tension within the Bitcoin community between those who prioritize strict adherence to the original vision of Bitcoin and those who advocate for evolution and adaptation.