Chun Wang, co-founder of major Bitcoin mining pool F2Pool, has voiced strong opposition to a proposed temporary soft fork designed to curb data spam on the Bitcoin network. Wang explicitly stated that BIP-444 is a "bad idea" and that neither he nor F2Pool will support any soft fork, regardless of its temporary nature. He expressed disappointment with what he perceives as developers moving in an "in the wrong direction."
Bitcoin Improvement Proposal (BIP)-444 is a temporary soft-fork proposal for the Bitcoin network. Its primary aim is to restrict the inclusion of arbitrary data, which proponents consider to be spam. The proposed soft fork would impose limitations on non-transaction data, which currently enables alternative uses for the Bitcoin blockchain, including a cap of 83 bytes for such data, among other restrictions.
BIP-444 and Its Rationale
BIP-444 appears to be a direct response to an update from leading Bitcoin node software, Bitcoin Core, in late September. This update removed the 80-byte limit previously imposed on OP_RETURN, a component of transaction scripts that allows users to embed arbitrary data.
This change has been interpreted by many as a move towards corporate capture of the Bitcoin blockchain, as it facilitates companies in building layer-two solutions and other infrastructure on Bitcoin. Furthermore, some argue that permitting more arbitrary data on-chain will lead to more rapid increases in blockchain size, higher node requirements, and increased centralization.
Others have pointed out that this issue is part of a long-standing debate that dates back to the earliest days of Bitcoin. Additionally, proponents of the change emphasize the difficulty in enforcing rules that may conflict with miners' incentives. A review conducted in January 2024 revealed that miners, including F2Pool, were already incorporating non-standard transactions that exceeded OP_RETURN limits.
The BIP, submitted by pseudonymous developer Dathon Ohm, is titled "Reduced Data Temporary Softfork." It proposes to "temporarily limit the size of data fields at the consensus level." This limit is intended to remain in effect until Bitcoin block 987,424, which is approximately 1.27 years from the current date.
In a dedicated mailing list, the creator explained the core idea: "the idea is to strongly reaffirm in consensus that bitcoin is money, not data storage." They added, "After a year, the soft fork expires, giving us time to come up with a more permanent solution."
Functionality of BIP-444
BIP-444 is designed as a temporary soft fork to restrict most data-embedding methods on Bitcoin. This includes implementing stricter size limits for outputs and pushes, prohibiting the use of annexes, unknown witness versions, deep Taproot trees, OP_SUCCESS* opcodes, and conditional branches. The proposal aims to limit Ordinal-based non-fungible token (NFT) creation, large data payloads, and complex scripts, while ensuring that simple monetary transactions remain unaffected.
The text of the BIP argues that with modern data compression techniques, it is feasible to embed "objectionable images (often illegal to even possess) in as few as 300–400 bytes." This capability could allow "a malicious actor to mine a single transaction with illegal or universally abhorrent content and credibly claim that Bitcoin itself is a system for distributing it."
However, Bitcoin developer and cypherpunk Peter Todd has contended that this approach is not effective in achieving its stated goal. Todd demonstrated this by successfully embedding the entire BIP-444 text within a Bitcoin transaction that would comply with the proposed soft fork.
Despite this, proponents of the change highlighted that the fee for such a transaction exceeded $100. They argued that if embedding illegal data is made more difficult, it "would not make sense to hold node operators legally responsible." They further explained:
If Bitcoin provides an officially supported method of storing arbitrary data [...] node operators could conceivably be held responsible for possession and distribution.
Nevertheless, some individuals view this distinction as arbitrary and impractical. One user on X demonstrated this point by sharing two commands capable of extracting data from an image stored on the Bitcoin network, illustrating the minimal practical differences in practice.
