From ZmnSCPxj at protonmail.com Tue Sep 21 02:11:42 2021 From: ZmnSCPxj at protonmail.com (ZmnSCPxj) Date: Tue, 21 Sep 2021 02:11:42 +0000 Subject: [Lightning-dev] Inherited IDs - A safer, more powerful alternative to BIP-118 (ANYPREVOUT) for scaling Bitcoin In-Reply-To: References: Message-ID: Good morning John Law, > (at the expense of requiring an on-chain transaction to update > the set of channels created by the factory). Hmmm this kind of loses the point of a factory? By my understanding, the point is that the set of channels can be changed *without* an onchain transaction. Otherwise, it seems to me that factories with this "expense of requiring an on-chain transaction" can be created, today, without even Taproot: * The funding transaction output pays to a simple n-of-n. * The above n-of-n is spent by an *offchain* transaction that splits the funds to the current set of channels. * To change the set of channels, the participants perform this ritual: * Create, but do not sign, an alternate transaction that spends the above n-of-n to a new n-of-n with the same participants (possibly with tweaked keys). * Create and sign, but do not broadcast, a transaction that spends the above alternate n-of-n output and splits it to the new set of channels. * Sign the alternate transaction and broadcast it, this is the on-chain transaction needed to update the set of channels. The above works today without changes to Bitcoin, and even without Taproot (though for large N the witness size does become fairly large without Taproot). The above is really just a "no updates" factory that cuts through its closing transaction with the opening of a new factory. Regards, ZmnSCPxj