From dave at dtrt.org  Sun Sep 24 21:40:29 2023
From: dave at dtrt.org (David A. Harding)
Date: Sun, 24 Sep 2023 11:40:29 -1000
Subject: [Lightning-dev] [bitcoin-dev] Scaling Lightning With Simple
	Covenants
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On 2023-09-17 18:14, ZmnSCPxj via bitcoin-dev wrote:
>> Let A_1 ... A_n denote a large number of casual users, let B be a 
>> dedicated user, and let E denote some fixed time in the future.
>> User B creates a timeout-tree with expiry E where:
>> ?* leaf i has an output that funds a Lightning channel owned by A_i 
>> and B, and
>> ?* after time E, each non-leaf output in the covenant tree can also be 
>> spent by user B without having to meet the conditions of the covenant.
> 
> I think, based solely on the description above, that it is not safe
> for dedicated user `B` to create this, unless it gets a signature from
> `A_i`.
> 
> The alternative is to also infect the leaf itself with a lifetime
> `(A_i && B) || (B && CLTV)`.
> [...] then `B` can dedicate that leaf output to a separate 1-input
> 1-output transaction that takes the `(A_i && B)` branch and spends to
> a plain `A && B` Lightning channel.

Good morning, ZmnSCPxj.

FYI: what you call an alternative is what appears to be shown in the 
paper in the diagram on page 6 and described in the text on page 7.

-Dave