Merged Mining

What is Merged Mining?

Merged Mining is the process of sharing hashrate across different blockchains. A Quai block header contains data for a Prime, Region, and Zone blockchain. The validity is determined by the amount of work found for the header. By combining the headers of our Prime, Region, and Zone blockchains, Quai Network is able to secure three networks up and down the hierarchy at once.
Mining of the combined header block is done inside of the Quai manager. The Quai manager is a program that sits on top of Quai Network that handles passing of external blocks via RPC.

Merged Mining in Quai Network

When mining on Quai Network, miners will select the latest header from the Prime blockchain, one of the three Region chains, and one the three Zone chains that belong to the chosen Region. In a 3x3 network, a Quai Network miner will be able to choose from 9 different "slices".
When mining the combined header of Prime, Region, and Zone, the miner will be able to find Prime, Region, and Zone blocks based on the difficulty requirement of each header. It is expected for Zones to have the lowest difficulty, which gives Zone blocks the lowest block time. Upon finding a block with higher difficulty (i.e Prime or Region), all blocks below the difficulty requirement are also valid. So when the Prime chain is extended, so is the Region and Zone chain of the slice being mined.
Read more about the history and capabilities of merged mining here.