Adam Back: BIP-110 flawed, could create minority Bitcoin fork

On June 8, Blockstream CEO Adam Back rejected BIP-110, calling the proposal technically flawed and lacking support across the Bitcoin ecosystem. He warned that forcing a user-activated soft fork would risk creating a minority, contentious chain.

BIP-110 would impose a default limit on non-monetary data in Bitcoin transactions. The change would be enforced by node software rather than through miner agreement. Proponents say the measure would reduce on-chain data bloat and unwanted payloads.

Back argued the design would not work as advertised and that the proposal has not achieved technical or ecosystem consensus. He contrasted the proposal with Segregated Witness, noting SegWit reached broad coordination among developers, miners and node operators before activation in 2017, even though the later activation process saw disputes.

On Twitter, Back called the proposal “stupid” and wrote that it “completely fails at technical consensus.” He posted an image labeled “DEFAULT OP_RETURN LIMIT” with the caption “the 110 contentious fork in a nutshell,” reflecting his view that the change would enforce a rule the wider network does not accept.

Investor Michael Saylor described BIP-110 as “Bitcoin’s biggest self-inflicted risk,” raising alarm among some industry participants. Critics have also accused the proposal’s lead backer of misrepresenting past events related to activation processes.

The UASF activation route depends on node operators enforcing the new rules. Back and other critics say that approach bypasses established coordination among developers, miners and node operators and increases the chance of a split if miners continue to build on the existing rules. Observers and proponents report node support remains at low single-digit percentages and that the proposal’s activation window narrows in the coming months.

Back has published a separate essay on Bitcoin treasury arbitrage, linking his views on sound money to longer-term asset value. On June 9 he reiterated a bullish outlook on Bitcoin, identifying “the bitcoin permabulls” as those who remain fully committed to BTC.

Supporters of BIP-110 maintain the proposal would limit non-monetary uses of block space and reduce unwanted data on chain. Opponents point to low node adoption and the risk of a contentious fork if a UASF proceeds without broad agreement. Whether BIP-110 can secure wider backing before its activation deadline remains undecided.