Date: Sun, 17 Sep 2023 00:56:04 +0000
To: Rusty Russell <rusty@rustcorp.com.au>
From: jlspc <jlspc@protonmail.com>
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Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>,
 "lightning-dev@lists.linuxfoundation.org"
 <lightning-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Scaling Lightning With Simple Covenants
Precedence: list

Hi Rusty,

>         I've read the start of the paper on my vacation, and am still
> digesting it.  But even so far, it presents some delightful
> possibilities.

Great!

> As with some other proposals, it's worth noting that the cost of
> enforcement is dramatically increased.  It's no longer one or two txs,
> it's 10+.  If the "dedicated user" contributes some part of the expected
> fee, the capital efficiency is reduced (and we're back to "how much is
> enough?").

Yes, this is certainly an issue, and it affects both settling the channel o=
n-chain and resolving HTLCS on-chain.
The paper has a few ideas about how "short-cut" transactions could be used =
to address the cost of enforcing HTLCs on-chain.
It may be possible to do something similar for the channel itself, but that=
's more complex because of the value included in the channel and the potent=
ial for channels with different capacities in a single timeout-tree.

> But worst case (dramatic dedicated user failure) it's only a 2x penalty
> on number of onchain txs, which seems acceptable if the network is
> sufficiently mature that these failure events are rare.

> Note also that the (surprisingly common!) "user goes away" case where
> the casual user fails to rollover only returns funds to the dedicated
> user; relying on legal and normal custody policies in this case may be
> preferable to an eternal burden on the UTXO set with the current
> approach!

Agreed.

Thanks,
John

> Thankyou!
> Rusty.


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