Merged mining is the process that allows RSK blockchain to be mined simultaneously with Bitcoin blockchain. This can be done because both chains use the same PoW algorithm (double SHA-256).
Bitcoin mining pools include a reference to RSK’s block in every mining job they deliver to miners. Everytime miners find a solution, it is compared to both networks difficulties (Bitcoin and RSK) delivering three possible outcomes:
Solution submitted to RSK allows the node to build an SPV proof. If the proof is valid, it is included as part of the block that will be sent to the network.
Miners earn a high percentage of transaction fees from the RSK block they mine. This mining process is done with the same hashing power used in Bitcoin mining and has no additional cost or impact.
You can see RSK network hashing power in our Stats Website.
Check our implementation guide.