Merged Mining is a New method for mining drivechains via game theory


Blind merged mining (BMM) is a new method for mining drivechains. BMM uses game theory to help ensure that miners will help keep drivechains fully functional. A full sub-chain node generates a block that assigns itself any fees from block transactions. The sub-chain node then contacts a mainchain miner and asks the miner to include a hash or other cryptographic proof to the mainchain coinbase transaction. The hash or proof allows the next block in the sub-chain - the one generated by the node - to be added and anchored to the mainchain. A new opcode (e.g., OP_VERIFYBMMBLOCK) would be required to make the functionality work on the mainchain.

The full sub-chain node gets the mainchain miner to add the hash by offering the miner a mainchain fee.

The fee is defined as the value of the sub-chain block: The sub-chain block fees, minus an "epsilon" value. When paying the miner, the full sub-chain node essentially keeps the epsilon value. According to game theory, the miners will wish to maximize their fees by minimizing the epislon. Full sub-chain nodes will have an incentive to maximize fees so as to compensate for the minimal epsilon.

Note that the sub-chain withdrawal security level is SPV; the mainchain miners give no guarantee that they'll verify the sub-chain block. Because of this, disputes could arise. In order to resolve disputes, it is possible for miners to temporarily become full sub-chain nodes. The miners can help determine the chain with the most work, thereby resolving the dispute.