Bitcoin developer Chris Guida has dusted off code that could swap the mining algorithm on a breakaway BIP-110 chain if supporters fail to overcome miners’ resistance. With the activation height closing in fast, supporters are now openly floating a proof-of-work (PoW) swap if BIP-110 leaves them stranded on a weak minority chain that stops moving.
Key Takeaways
Chris Guida rebased 2017 PoW fork code as BIP-110’s Aug. 8-9 window nears.BIP-110’s 55% threshold tests whether Bitcoin nodes can overcome miner resistance.Start9 closed Lightning channels before block 961632 as split risks grew“People seem to think that the intention is for this pow change to activate immediately,” the developer wrote. “That’s not the case This is just some code to have in our back pocket in case miners betray bitcoin, to activate at some point later.”
BIP-110, formally called the Reduced Data Temporary Softfork, would tighten Bitcoin’s rules on arbitrary data for roughly one year. It would limit certain contiguous data, reduce permitted script sizes and restore an 83-byte consensus limit for OP_RETURN, a transaction field that can be used to attach data. Supporters say the restrictions would return the base layer’s focus to financial activity and reduce legal or operational risks for node operators.
Voluntary signaling has remained low, even as Bitcoin Knots adoption has appeared higher among reachable nodes. That gap matters because miners provide the computing power that advances the chain, while nodes independently decide which blocks and rules they accept. When miners and a meaningful group of nodes follow incompatible rules, Bitcoin can divide into competing histories, ultimately leaving businesses and users to decide which chain they recognize.
A PoW Switch Would Strand Today’s ASICsBitcoin currently uses double SHA-256, known as SHA-256d, as its PoW algorithm. Specialized machines called application-specific integrated circuits, or ASICs, perform that calculation far more efficiently than ordinary computers and account for nearly all modern bitcoin mining. Changing the algorithm would make those machines ineffective on the new chain unless developers selected a compatible replacement.
Guida’s code allows a future hard fork to switch algorithms after a configurable time. The available options include SHA-256, SHA-256d, RIPEMD-160 and HASH160, although the mainnet setting leaves the fork unscheduled by default. Any actual launch would require developers and users to agree on an algorithm, activation time, software release and coordination plan. No such schedule currently exists.
The first block under the replacement algorithm would receive a mining target roughly 1 million times easier under the default setting. That reset is intended to help a chain with little initial computing power produce blocks instead of freezing. Normal difficulty rules would then resume. Supporters see the mechanism as leverage against miners, while critics say it could destroy mining investment, fragment liquidity and create a minority cryptocurrency with weak infrastructure support.
Lightning Operators Move to Limit Fork ExposureFor now, Guida’s proof-of-work branch remains an unused contingency. The immediate test is whether bitcoin miners change their signaling behavior during the mandatory window and whether enforcing nodes remain on a viable chain. The next signals to watch are official Bitcoin Knots releases, miner support, Lightning channel closures, exchange policies and any move to give the hard-fork code a specific algorithm or activation date.
