The thought is that Bitcoin miners are blind to the sidechain/spacechain that’s being merge-mined.
In regular merge-mining Bitcoin miners that select to take part should run a node on the separate blockchain (Namecoin, Rootstock, for instance) and truly construct the block for these chains, then embrace it someplace of their Bitcoin block. See https://bitcoin.stackexchange.com/a/35870/1026 for a extra detailed rationalization.
In blind merge-mining constructs, akin to Spacechains, a brand new function is added between the parallel chain that’s being merge-mined and Bitcoin: that of BMM miners.
The BMM miners acquire charges and construct the blocks on the parallel chain and submit their hash for inclusion on Bitcoin in what we are able to name a BMM transaction. They pay Bitcoin miners a price in BTC. Bitcoin miners can simply embrace these hashes and acquire the charges with out caring about their which means, with out having to run a node on this parallel chain.
It is anticipated that competitors between a number of BMM miners will drive up the BTC price paid within the BMM transaction as much as principally the identical quantity of charges they acquire on the parallel chain.
The toughest a part of implementing such a protocol is making certain that Bitcoin miners do not embrace multiple BMM hash for a similar parallel chain in the identical Bitcoin block. That’s unhealthy as a result of:
- It may be messy for the parallel chain — it must have tough and complicated guidelines in an effort to decide what block is legitimate, for instance.
- It is wasteful — it is going to use Bitcoin block area for no goal.
- It undermines the objective of turning charges collected within the parallel chain into BTC paid on to Bitcoin miners — since there is no such thing as a atomicity ensures between paying the BMM transaction price and truly having a sound block accepted within the parallel chain, there is no such thing as a incentive for competing BMM miners to bid the BTC price as much as the quantity acquired on the parallel chain.
There are a number of methods of reaching these atomicity ensures, such because the Ruben Somsen covenants BMM/Spacechain proposal and the BIP-301/Drivechain proposal.