The RSK blockchain is merge-mined with a block time of around 30 sek. Blocks are produced when bitcoin miners create valid block headers within the target. The RSK difficulty is far lower than bitcoin's. That means that valid hashes for the bitcoin blockchain are always valid on RSK but even invalid hashes for the bitcoin blockchain are sometimes valid on RSK. When the hash satisfies both RSK and bitcoin's difficulty, miners often include an RSK-tagged output in the coinbase.

The above is my understanding of RSK's merge-mining. My question is why would a bitcoin miner use precious block space for the RSK-tagged output in the coinbase?

My reasoning is that a RSK block is valid as long as the header satisfies the target difficulty whether or not it's a valid bitcoin block as well.

My incomplete knowledge is based (& my curiosity sparked) on this https://blog.rsk.co/noticia/rsk-bitcoin-merge-mining-is-here-to-stay/

1 Answer 1


The advantages would be receiving RSK sidechain fees on the RSK-mined transactions.

The disadvantages would be the logistic overhead of running an RSK node, the latency introduced by querying it for block mining, and the opportunity cost of space the sidechain commitment that now can't be used for transactions.

(note that I'm not an expert on RSK at all, and this answer is mostly based on generic understanding of sidechains)

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.