From: Gregory Maxwell <greg@xiph.org>
To: Peter Todd <pete@petertodd.org>,
Bitcoin Protocol Discussion
<bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Transaction Merging (bip125 relaxation)
Date: Tue, 23 Jan 2018 21:31:00 +0000 [thread overview]
Message-ID: <CAAS2fgSJ=2GaX-fNRyZhwD=g6=v524hnD-dCqJicC-ak+La4PA@mail.gmail.com> (raw)
In-Reply-To: <20180122200023.GA1055@savin.petertodd.org>
On Mon, Jan 22, 2018 at 8:00 PM, Peter Todd via bitcoin-dev
<bitcoin-dev@lists.linuxfoundation.org> wrote:
> Most transactions don't have change?! Under what circumstance? For most
> use-cases the reverse is true: almost all all transactions have change, because
> it's rare for the inputs to exactly math the requested payment.
It's quite easy to get no change with a not-dumb algorithm selecting
coins if you have a decent number of outputs well under the value
you're paying.
The number of ways n choose m combines grows exponentially, and you
only need to get close enough over the right value so that you're
paying excess fees equal or less than the cost of the change (which
should include the current cost output itself as well as estimated
cost of the future signature to spend it).
Achow101 and Murch have code to implement an efficient algorithm for
finding these solutions for Bitcoin core which will hopefully get in
soon.
next prev parent reply other threads:[~2018-01-23 21:31 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-22 17:40 [bitcoin-dev] Transaction Merging (bip125 relaxation) Rhavar
2018-01-22 18:16 ` Alan Evans
2018-01-22 18:18 ` Rhavar
2018-01-22 18:50 ` Moral Agent
2018-01-22 18:59 ` Rhavar
2018-01-22 20:00 ` Peter Todd
2018-01-22 20:09 ` Rhavar
2018-01-23 16:31 ` Rhavar
2018-01-23 21:56 ` Moral Agent
2018-01-23 22:19 ` Rhavar
2018-01-23 22:49 ` Gregory Maxwell
2018-01-24 7:44 ` Peter Todd
2018-01-24 13:43 ` Alan Evans
2018-01-24 16:05 ` Rhavar
2018-01-28 16:43 ` Sjors Provoost
2018-01-28 17:29 ` David A. Harding
2018-01-28 17:58 ` Rhavar
2018-01-28 18:08 ` Moral Agent
2018-01-23 21:31 ` Gregory Maxwell [this message]
2018-01-24 7:28 ` Peter Todd
2018-01-23 23:31 Adam Ficsor
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAAS2fgSJ=2GaX-fNRyZhwD=g6=v524hnD-dCqJicC-ak+La4PA@mail.gmail.com' \
--to=greg@xiph.org \
--cc=bitcoin-dev@lists.linuxfoundation.org \
--cc=pete@petertodd.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox