BIP 301

BIP-301 is the companion proposal to BIP-300 (drivechains). It defines blind merged mining, the mechanism by which Bitcoin miners would mine blocks on drivechains without having to actually run those sidechains' software or validate their transactions.

How blind merged mining works:

1. A drivechain produces block templates internally, including a "header hash" that commits to the sidechain block.
2. The drivechain block's header hash gets embedded in a Bitcoin mainnet transaction's OP_RETURN or witness data.
3. A Bitcoin miner who finds a mainnet block that includes this commitment is automatically considered to have "found" the corresponding sidechain block.
4. The miner earns sidechain transaction fees without running the sidechain or validating its contents - hence "blind."

The point: Bitcoin miners can earn fees from many sidechains simultaneously by including their commitment hashes in their mainnet blocks. They don't need to run validators for each sidechain; they just need to include the hashes.

The arguments for:

• Lower overhead for miners. They don't have to maintain N different sidechain validators.
• Easier ecosystem expansion. New sidechains can launch without requiring miner buy-in.
• Fee revenue diversification. Miners get income from sidechain activity, not just Bitcoin transaction fees.

The arguments against:

• Miner power further concentrates. Combined with BIP-300's peg-out voting, blind merged mining gives miners economic incentives across many chains and political authority over peg-outs.
• "Blind" is doing a lot of work. Miners are economically committed to sidechains they're not validating. If those sidechains have rule disputes or attacks, miner incentives might pull them toward outcomes that benefit them economically rather than what's "right."

BIP-301 stands or falls with BIP-300. Neither has activated as of 2026. See BIP-300 for the framing and Merged Mining for the underlying technique.