TLDR
- Bitcoin Core v30 update introduces significant changes, including a new wallet format and the ability to include non-monetary data.
- The update removes the 80-byte limit on OP_RETURN, potentially allowing up to 4 megabytes of data per transaction output.
- Critics warn that the expansion of OP_RETURN could lead to blockchain bloat, increasing costs and risks of spam or malware.
- Nick Szabo entered the debate, raising concerns about the legal risks for Bitcoin nodes storing harmful data on the blockchain.
- The Bitcoin Core team supports the update, but the release remains uncertain due to ongoing testing and community debate.
The Bitcoin Core Project has announced the second test version of its Bitcoin Core v30 update. The update introduces a new wallet format and allows non-monetary data inclusion. This new version is set to release in late October after further testing. However, it has stirred controversy within the Bitcoin community.
The main issue surrounding the Bitcoin Core update is the changes to the OP_RETURN opcode. The update removes the default 80-byte cap on data storage, allowing up to 4 megabytes per transaction output. This change has sparked intense debate, especially regarding the potential for blockchain bloat.
Some developers, including Bitcoin maximalists, argue that the update is necessary. They believe that if users pay transaction fees, they should be able to use block space as they see fit. Market forces, they claim, will naturally limit malicious usage due to the costs involved.
Bitcoin Core Update Could Increase Spam and Malware Risks
A significant aspect of the Bitcoin Core v30 update is the expansion of OP_RETURN. This opcode allows for embedding arbitrary data in Bitcoin transactions. With the new changes, the data limit is effectively unlimited, which has raised concerns about network efficiency.
Critics of the Bitcoin Core update worry that this will lead to blockchain bloat. If large amounts of non-financial data are included, Bitcoin nodes will be forced to store more information. This would result in higher operating costs and could cause the network to become slower and more costly for participants.
Furthermore, critics fear that the increased data storage limits will lead to spam and potential malware risks. They argue that allowing such large data blocks could make the network more vulnerable to attacks. The Bitcoin Core team, however, believes the update is necessary for the network’s growth and flexibility.
A new release candidate of Bitcoin Core, v30.0rc2, is available for testing.
This is a new major release, and follows v29.0.
Work-in-progress release notes are here: https://t.co/5oFSOBoXGM
It is available here: https://t.co/sxUTx7Gmu0— Bitcoin Core Project (@bitcoincoreorg) September 28, 2025
Nick Szabo Weighs in on Legal Risks and Network Security
Bitcoin pioneer Nick Szabo has entered the debate surrounding the Bitcoin Core update. Szabo, who recently returned to social media after a five-year hiatus, raised concerns about the potential legal risks. He argued that increasing the OP_RETURN allowance could create further legal complications for Bitcoin nodes.
He highlighted that the increased data could lead to more dangerous content being stored on the blockchain.
“The network fees protect miners, but they don’t do enough to protect full nodes,” Szabo stated. He also pointed out that “it’s an open legal issue almost everywhere,” suggesting that nodes could be held accountable for harmful data.
Szabo emphasized that the nature of OP_RETURN makes data prunable, which could reduce some legal risks. However, he warned that easily accessible and viewable data could increase legal risks. He said, “Standard formats that are easily accessible are more likely to cause problems with legal authorities.”
