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From: Rusty Russell <rusty@rustcorp.com.au>
To: Mark Friedenbach <mark@friedenbach.org>,
	Gregory Maxwell <gmaxwell@gmail.com>
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] [RFC] Canonical input and output ordering in transactions
Date: Tue, 16 Jun 2015 06:31:04 +0930	[thread overview]
Message-ID: <87eglcelf3.fsf@rustcorp.com.au> (raw)
In-Reply-To: <CAOG=w-tJjzrR_REJOShULfSO=T3ueHko-oQHdhqMCdZD0G_BDA@mail.gmail.com>

Mark Friedenbach <mark@friedenbach.org> writes:
> There's another important use case which you mentioned Greg, that also
> requires special exemption: compact commitments via mid-state compression.
>
> The use case is an OP_RETURN output sorted last, whose last N bytes are a
> commitment of some kind. A proof of the commitment can then use mid state
> compression to elide the beginning of the transaction.
>
> How do you make a special exemption for this category of outputs? I can't
> think of a very clean way of doing so that doesn't require an ugly
> advertising of sort-order exemptions.

Yes, we can suit any one use case, but not all of them.

For example, outputs shall be sorted by:
        1.  First byte (or 0 if script is zero length) minus 107.
        2.  The remainder of the script in lexographical order.

This would put OP_RETURN outputs last.

Though Peter Todd's more general best-effort language might make more
sense.  It's not like you can hide an OP_RETURN transaction to make it
look like something else, so that transaction not going to be
distinguished by non-canonical ordering.

Cheers,
Rusty.



  reply	other threads:[~2015-06-15 21:42 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
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 [this message]
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

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