Subject: Re: [bitcoin-dev] [Lightning-dev] Removing the Dust Limit

From: ZmnSCPxj <[email-masked]>
Date: Thu, 07 Oct 2021 04:52:01 +0000

Good morning e,

> mostly thinking out loud
>
> suppose there is a "lightweight" node:
>
> 1.  ignores utxo's below the dust limit
> 2.  doesn't validate dust tx
> 3.  still validates POW, other tx, etc.
>
>     these nodes could possibly get forked - accepting a series of valid,
>     mined blocks where there is an invalid but ignored dust tx, however
>     this attack seems every bit as expensive as a 51% attack

How would such a node treat a transaction that spends multiple dust UTXOs and creates a single non-dust UTXO out of them (after fees)?
Is it valid (to such a node) or not?

I presume from #1 it never stores dust UTXOs, so the node cannot know if the UTXO being spent by such a tx is spending dust, or trying to spend an already-spent TXO, or even inventing a TXO out of `/dev/random`.

Regards,
ZmnSCPxj