What is merged mining?

Merged Mining is a process that enables cryptocurrency miners to mine two or more blockchain networks simultaneously; this allows them to compete for, and claim, separate block rewards without sacrificing their overall mining performance. “The act of using work done on one blockchain on more than one chain, using Auxiliary Proof of Work (AuxPoW).”

Is merged mining a good idea for emerging blockchains?

Ideally, miners would have no issue in switching to merged mining because they receive increased rewards for the same amount of work. Therefore, this type of mining could be a reliable way for emerging blockchains to protect themselves against 51% attacks as they scale. The parent chain is unaffected.

Is merged mining a threat to network centralization?

For some, merged mining poses the realistic threat of network centralization, something which has, at times, made merged mining a controversial topic. For example, a mining pool that contributes a small proportion of Bitcoin’s total hash rate could easily reach <51% on a smaller chain.

Will a merged mining protocol increase network activity & security?

By attracting more miners, both network activity and security will hypothetically increase as long as enough miners agree to adopt the merged mining protocol - this can help reduce the possibility of a 51% attack - a network attack that can only occur if a single entity controls more than 51% of a network's hashing power.