📅 Original date posted:2020-04-23 📝 Original message: On 4/23/20 8:46 AM, ZmnSCPxj wrote: >>> - Miners, being economically rational, accept this proposal and include this in a block. >>> >>> The proposal by Matt is then: >>> >>> - The hashlock branch should instead be: >>> - B and C must agree, and show the preimage of some hash H (hashlock branch). >>> - Then B and C agree that B provides a signature spending the hashlock branch, to a transaction with the outputs: >>> - Normal payment to C. >>> - Hook output to B, which B can use to CPFP this transaction. >>> - Hook output to C, which C can use to CPFP this transaction. >>> - B can still (somehow) not maintain a mempool, by: >>> - B broadcasts its timelock transaction. >>> - B tries to CPFP the above hashlock transaction. >>> - If CPFP succeeds, it means the above hashlock transaction exists and B queries the peer for this transaction, extracting the preimage and claiming the A->B HTLC. >> >> Note that no query is required. The problem has been solved and the preimage-containing transaction should now confirm just fine. > > Ah, right, so it gets confirmed and the `blocksonly` B sees it in a block. > > Even if C hooks a tree of low-fee transactions on its hook output or normal payment, miners will still be willing to confirm this and the B hook CPFP transaction without, right? Correct, once it makes it into the mempool we can CPFP it and all the regular sub-package CPFP calculation will pick it and its descendants up. Of course this relies on it not spending any other unconfirmed inputs.