Bitcoin Knots prepares BLAKE2b fork test after previous split failed

Weekend rehearsal planned for new mining algorithm

Bitcoin developer Luke Dashjr announced on Aug. 29 that Bitcoin Knots is preparing a test of a breakaway network using the BLAKE2b proof-of-work algorithm. The attempt aims to follow a previous split called BIP-110, which failed after producing only two blocks.

Dashjr asked SHA-2 miners to stop mining ahead of the test scheduled for Sunday. Bitcoin Knots version 29.4.1rc4 will establish the final SHA-2 block before the switch. If the test succeeds, a final version could launch the new chain on Sept. 1. If problems occur, the team will release another candidate and reset to the last SHA-2 block.

The proposal tries to solve a key weakness from the earlier split. Instead of relying on miners who secure the main Bitcoin chain, the new network would reject old blocks and use BLAKE2b hardware. Backers say miners originally built for the Sia network, such as the Bitmain Antminer A3 and Goldshell SC5, can support this system.

Mining capacity and node rules remain uncertain

• A reviewer calculated that initial difficulty might require roughly 870 terahashes per second, but current testnet capacity is estimated at only 50 to 70 TH/s.
• The public Bitcoin Knots release page did not yet show the rc4 update or a final build as of Aug. 29.
• There is a discrepancy in the proposed block-weight limit: the FAQ lists 700,000 units, while a source commit shows 800,000.
• The project has not yet identified major exchanges, wallets, or custodians committed to supporting the new chain.

Technical details still being finalized

The BLAKE2b implementation and a related reduced-data proposal remain open as of Aug. 29. The mainnet activation height has not been fixed in the public materials. The proof-of-work change would be permanent, but the reduced-data restrictions, including the smaller block cap, are scheduled to expire in 2027.

Nodes enforcing different block limits could disagree on validity, making the final configuration critical before participants follow the same chain.

Infrastructure and replay risks

Even if the chain works technically, it faces a coordination test outside the core software. The new chain uses a 164-byte block header, while existing light wallets expect Bitcoin's 80-byte format. Dashjr stated that light-client compatibility falls outside Bitcoin Knots' scope, meaning infrastructure providers may need changes.

The project also faces replay risk, where a transaction spending pre-fork coins could be valid on both chains. Bitcoin Knots proposed a SIGHASH_UNIFIED signing mode for directional protection, but it would not automatically protect every existing wallet. The switch does not make ownership keys quantum-safe, as it does not replace existing addresses or signatures.

Why this matters for the network

The immediate test is whether Bitcoin Knots can produce and maintain a BLAKE2b chain after the BIP-110 failure. A successful test would show the fork can run, but it would not prove that enough miners, infrastructure providers, and users are prepared to keep it economically viable.

The larger question remains whether the new chain can attract the hash rate and community support needed to survive long-term.

• CryptoSlate