Good morning Erik, > > As I understand your counterproposal, it would require publishing one > > transaction per evicted participant. > > if you also pre-sign (N-2, N-3, etc), you can avoid this
It also increases the combinatorial explosion. > > In addition, each participant has to store `N!` possible orderings in which > > participants can be evicted, as you cannot predict the future and cannot > > predict which partiicpants will go offline first. > > why would the ordering matter? these are unordered pre commitments to move > funds, right? you agree post the one that represents "everyone that's > offline" Suppose `B` is offline first, then the remaining `A` `C` and `D` publish the eviction transaction that evicts only `B`. What happens if `C` then goes offline? We need to prepare for that case (and other cases where the participants go offline at arbitrary orders) and pre-sign a spend from the `ACD` set and evicts `C` as well, increasing combinatorial explosion. And so on. We *could* use multiple Tapleaves, of the form `<A> OP_CHECKSIG <BCD> OP_CHECKSIG` for each participant. Then the per-participant `<A>` signature is signed with `SIGHASH_SINGLE|SIGHASH_ANYONECANPAY` and is pre-signed, while the remainder is signed by `<BCD>` with default `SIGHASH_ALL`. Then if one participant `B` is offline they can evict `B` and then the change is put into a new UTXO with a similar pre-signed scheme `<A> OP_CHECKSIG <CD> OP_CHECKSIG`. This technique precludes pre-signing multiple evictions. > > > But yes, certainly that can work, just as pre-signed transactions can be > > used instead of `OP_CTV` > > i don't see how multiple users can securely share a channel (allowing massive > additional scaling with lighting) without op_ctv They can, they just pre-sign, like you pointed out. The same technique works --- `OP_CTV` just avoids having ridiculous amounts of combinatorial explosion and just requires `O(log n)` per eviction. Remember, this proposal can be used for channel factories just as well, as pointed out, so any objection to this proposal also applies to `OP_CTV`. Regards, ZmnSCPxj _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
