Date: Tue, 10 May 2022 16:45:19 +0000
To: Billy Tetrud <billy.tetrud@gmail.com>,
 Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
From: ZmnSCPxj <ZmnSCPxj@protonmail.com>
Reply-To: ZmnSCPxj <ZmnSCPxj@protonmail.com>
Message-ID: <mcikQmSFmiZw6Tq1GocybVcjGHNc-u9cP1aoZpJU-HEfgcqXXi1WhZSnEDMtEz3GfqAJGWpfZXjEBmsCXNSyLAgVNNcsSklERd-DJ8KeocE=@protonmail.com>
In-Reply-To: <CAGpPWDa2wofye=KSq-vVNS0SOU34st9wm-hMhiYzGLTKMGuP5w@mail.gmail.com>
References: <CALZpt+GNoRdbtfeBtpnitiAZ4jGwSsRpSRXOyX7mzrhwewmBcw@mail.gmail.com>
 <CAGpPWDa2wofye=KSq-vVNS0SOU34st9wm-hMhiYzGLTKMGuP5w@mail.gmail.com>
Feedback-ID: 2872618:user:proton
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Subject: Re: [bitcoin-dev] Conjectures on solving the high interactivity
	issue in payment pools and channel factories
Precedence: list

Good morning Billy,


> Very interesting exploration. I think you're right that there are issues =
with the kind of partitioning you're talking about. Lightning works because=
 all participants sign all=C2=A0offchain states (barring data loss). If a p=
articipant can be excluded from needing to agree to a new state, there must=
 be an additional mechanism to ensure the relevant state for that participa=
nt isn't changed to their detriment.=C2=A0
>
> To summarize my below email, the two techniques I can think for solving t=
his problem are:
>
> A. Create sub-pools when the whole group is live that can be used by the =
sub- pool=C2=A0participants later without the whole group's involvement. Th=
e whole group is needed to change the whole group's state (eg close or open=
 sub-pools), but sub-pool=C2=A0states don't need to involve the whole group=
.

Is this not just basically channel factories?

To reduce the disruption if any one pool participant is down, have each sub=
-pool have only 2 participants each.
More participants means that the probability that one of them is offline is=
 higher, so you use the minimum number of participants in the sub-pool: 2.
This makes any arbitrary sub-pool more likely to be usable.

But a 2-participant pool is a channel.
So a large multiparticipant pool with sub-pools is just a channel factory f=
or a bunch of channels.

I like this idea because it has good tradeoffs, so channel factories ho.

Regards,
ZmnSCPxj