Date: Mon, 2 May 2016 22:05:11 -0400
From: Peter Todd <pete@petertodd.org>
To: Kristov Atlas <kristovatlas.lists@gmail.com>
Message-ID: <20160503020511.GK15664@fedora-21-dvm>
References: <CAGH37S+5FAqHzOTE8H0E8HNb5cr1k06MqB2r3k92jqkc=eXWNg@mail.gmail.com>
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In-Reply-To: <CAGH37S+5FAqHzOTE8H0E8HNb5cr1k06MqB2r3k92jqkc=eXWNg@mail.gmail.com>
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Cc: Bitcoin Dev <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] segwit subsidy and multi-sender (coinjoin)
 transactions
Precedence: list


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On Fri, Apr 29, 2016 at 02:22:32PM -0400, Kristov Atlas via bitcoin-dev wro=
te:
> A sample of the 16 transaction id's posted in the JoinMarket thread on
> BitcoinTalk shows an average ratio of 1.38 or outputs to inputs:
>=20
> https://docs.google.com/spreadsheets/d/1p9jZYXxX1HDtKCxTy79Zj5PrQaF20mxbD=
7BAuz0KC8s/edit?usp=3Dsharing
>=20
> As we know, a "traditional" CoinJoin transaction creates roughly 2x UTXOs
> for everyone 1 it consumes -- 1 spend and 1 change -- unless address reuse
> comes into play.

Note how this is obviously an unsustainable situation - at some point that
change needs to be combined again, or you're throwing away money in the for=
m of
UTXO's that aren't ever getting spent.

Meanwhile, if you put it another way the segwit discount is an obvious
advantage for coinjoin: by making spending UTXO's cheaper, we can recover t=
hose
funds that would otherwise get lost to dust, becoming ever more difficult to
spend.

--=20
https://petertodd.org 'peter'[:-1]@petertodd.org

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