Let’s say Attacker sends me 10,000 Bitcoin in exchange for $1 billion USD, but secretly starts mining a chain where the 10,000 Bitcoin was sent to himself.
After I release the $1 billion USD, he broadcasts his heavier chain, undoing the transaction and keeping my $1 billion.
In response, I broadcast a child-pays-for-parent transaction from “my” UTXO on the shorter chain: the one that Attacker undid. I attach an extremely large fee, for example, 100 Bitcoin.
My hope is that honest miners would see that this child transaction is invalid on the longest chain, but it would be valid if they mine on the shorter chain. Then, this would induce more hash power to come online to reap the extremely profitable fees, which would overpower and undo Attacker’s re-org.
Does the game theory on this make sense? How high would my fee have to be in order for honest miners to determine that the EV of trying to mine on the shorter chain is worth it?
