public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: Mark Friedenbach <mark@friedenbach.org>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Bitcoin Development <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] [RFC] Canonical input and output ordering in transactions
Date: Fri, 5 Jun 2015 21:46:17 -0700	[thread overview]
Message-ID: <CAOG=w-sfpgciy9AzmtjEU5-uZY5KCAuS-SGsbff81w1dGVyBPg@mail.gmail.com> (raw)
In-Reply-To: <87k2vhfnx9.fsf@rustcorp.com.au>

[-- Attachment #1: Type: text/plain, Size: 2199 bytes --]

Rusty, this doesn't play well with SIGHASH_SINGLE which is used in
assurance contracts among other things. Sometimes the ordering is set by
the signing logic itself...
On Jun 5, 2015 9:43 PM, "Rusty Russell" <rusty@rustcorp.com.au> wrote:

> Title: Canonical Input and Output Ordering
> Author: Rusty Russell <rusty@rustcorp.com.au>
> Discussions-To: "Bitcoin Dev" <bitcoin-development@lists.sourceforge.net>
> Status: Draft
> Type: Standards Track
> Created: 2015-06-06
>
> Abstract
>
> This BIP provides a canonical ordering of inputs and outputs when
> creating transactions.
>
> Motivation
>
> Most bitcoin wallet implementations randomize the outputs of
> transactions they create to avoid trivial linkage analysis (especially
> change outputs), however implementations have made mistakes in this area
> in the past.
>
> Using a canonical ordering has the same effect, but is simpler, more
> obvious if incorrect, and can eventually be enforced by IsStandard() and
> even a soft-fork to enforce it.
>
> Specification
>
> Inputs should be ordered like so:
>         index (lower value first)
>         txid (little endian order, lower byte first)
>
> Outputs should be ordered like so:
>         amount (lower value first)
>         script (starting from first byte, lower byte first, shorter wins)
>
> Rationale
>
> Any single wallet is already free to implement this, but if other
> wallets do not it would reduce privacy by making those transactions
> stand out.  Thus a BIP is appropriate, especially if this were to
> become an IsStandard() rule once widely adopted.
>
> Because integers are fast to compare, they're sorted first, before the
> lexographical ordering.
>
> The other input fields do not influence the sort order, as any valid
> transactions cannot have two inputs with the same index and txid.
>
> Reference Implementation
>
> https://github.com/rustyrussell/bitcoin/tree/bip-in-out-ordering
>
>
> ------------------------------------------------------------------------------
> _______________________________________________
> Bitcoin-development mailing list
> Bitcoin-development@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/bitcoin-development
>

[-- Attachment #2: Type: text/html, Size: 3027 bytes --]

  reply	other threads:[~2015-06-06  4:46 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-06  4:42 [Bitcoin-development] [RFC] Canonical input and output ordering in transactions Rusty Russell
2015-06-06  4:46 ` Mark Friedenbach [this message]
2015-06-06  6:44   ` Rusty Russell
2015-06-06  8:24   ` Wladimir J. van der Laan
2015-06-06  9:45     ` Mark Friedenbach
2015-06-08 21:25 ` Danny Thorpe
2015-06-08 21:36   ` Peter Todd
2015-06-14 23:04   ` Gregory Maxwell
2015-06-14 23:02 ` Gregory Maxwell
2015-06-15  2:29   ` Rusty Russell
2015-06-15  2:33     ` Gregory Maxwell
2015-06-15  2:47       ` Mark Friedenbach
2015-06-15 21:01         ` Rusty Russell
2015-06-16  7:10           ` Jorge Timón
2015-06-16  8:06             ` Rusty Russell
     [not found]               ` <CABm2gDpkwHvrsB8Dh-hsO6H9trcweEX9XGB5Jh5KLPsPY5Z1Sw@mail.gmail.com>
2015-06-21  7:27                 ` [Bitcoin-development] Fwd: " Jorge Timón
2015-06-15  4:01   ` [Bitcoin-development] " Kristov Atlas
2015-06-24 22:09     ` [bitcoin-dev] " Kristov Atlas

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='CAOG=w-sfpgciy9AzmtjEU5-uZY5KCAuS-SGsbff81w1dGVyBPg@mail.gmail.com' \
    --to=mark@friedenbach.org \
    --cc=bitcoin-development@lists.sourceforge.net \
    --cc=rusty@rustcorp.com.au \
    /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