Bitcoin Improvement Proposal 110 (BIP-110) has officially entered its mandatory signaling phase, but the new fork it created is struggling to gain traction, having managed to produce just two blocks in approximately eight hours.
The event was triggered at block 961,632 on Saturday, when nodes enforcing BIP-110 began rejecting any blocks that did not signal support for the proposal. However, the reception from the mining community has been lukewarm at best, with only 51 out of the previous 2,016 blocks signaling support—equating to a mere 2.53%. This is significantly below the 55% threshold required for early activation.
Understanding BIP-110
BIP-110, authored by the pseudonymous developer Dathon Ohm, proposes a set of temporary restrictions on Bitcoin’s block space usage that would last for about a year. The proposal aims to limit most new output scripts to 34 bytes, cap OP_RETURN outputs at 83 bytes, and impose restrictions on certain data pushes and witness elements to 256 bytes, as well as temporarily limiting some Taproot features.
Proponents argue that these restrictions are necessary to reduce inscriptions and non-financial data within Bitcoin transactions, which, they claim, inflate costs for node operators. However, critics believe that every user paying a transaction fee should be entitled to utilize block space as they see fit. In fact, a miner from AntPool was the first to mine a non-signaling block, which was accepted by the main network but rejected by BIP-110 nodes.
The Fork’s Challenges
Following the fork, a miner using Ocean produced the block that the breakaway chain continued to follow. This has resulted in two competing chains, but the disparity in their mining support is stark. The BIP-110 minority chain, although inheriting Bitcoin’s current mining difficulty, holds a mere fraction of the total hashpower, meaning that blocks on this chain are being produced at a much slower rate—hours apart instead of the usual ten minutes.
Bitcoin’s mining difficulty adjusts approximately every 2,016 blocks, and estimates suggest that the BIP-110 chain will not reach its next adjustment for another 350 days, compared to just 14 days for the main chain. By 6 a.m. UTC on Sunday, the main Bitcoin chain had advanced to block 961,681, while the BIP-110 chain lagged at block 961,633.
Moreover, there is a significant risk of transaction replay attacks; both chains are still accepting identical transactions. Consequently, a signed transaction on the fork could potentially be broadcast on the main Bitcoin network, creating a vulnerability for users.
Critics of BIP-110, including notable figures like Michael Saylor and Blockstream CEO Adam Back, warn that the proposal poses a risk of fragmenting Bitcoin. Developer Chris Guida has also suggested a potential proof-of-work change as a contingency plan should miner opposition persist, although no specific activation date has yet been established.
The mandatory signaling window for BIP-110 remains open until block 963,647, but with current miner support so low, the future of this proposal appears uncertain.
