From: Anthony Towns <aj@erisian•com.au>
To: Russell O'Connor <roconnor@blockstream•io>,
Bitcoin Protocol Discussion
<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] Safer sighashes and more granular SIGHASH_NOINPUT
Date: Thu, 13 Dec 2018 10:05:53 +1000 [thread overview]
Message-ID: <20181213000553.cikilodf65an225g@erisian.com.au> (raw)
In-Reply-To: <CAMZUoKkYcXt7O39zdpz494f9Jm195mBtWyrH3siX4PBEAf8OKQ@mail.gmail.com>
On Tue, Dec 11, 2018 at 05:50:24PM -0500, Russell O'Connor via bitcoin-dev wrote:
> On Sun, Dec 9, 2018 at 2:13 PM Johnson Lau <jl2012@xbt•hk> wrote:
> The current proposal is that a 64-byte signature will be used for the
> default “signing all” sighash, and 65-byte for other sighash types. The
> space saved will allow a few more txs in a block, so I think it worths
> doing. However, this also makes witness weight estimation more difficult in
> multisig cases.
This seems strange to me -- why wouldn't you just assume every signature
is 65 witness bytes, and just be grateful for the prioritisation benefit
if someone chooses a shorter signature? Your error margin is just 0.25
vbytes per signature.
> I tend to think in opposite terms. Is there a proof that any script can be
> transformed into an equivalent one that avoids witness weight malleability?
An alternative generalisation: is there a proof that all valid witnesses
will have a weight within some small range?
> Moreover, even if witness weight malleability is entirely avoidable, it always
> seems to come at a cost. Taking as an example libwally's proposed "
> csv_2of3_then_2" Script, it begins with "OP_DEPTH OP_1SUB OP_1SUB"
(DEPTH 2 NUMNOTEQUAL seems like it would have been more obvious...)
Cheers,
aj
next prev parent reply other threads:[~2018-12-13 0:06 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-19 22:37 Pieter Wuille
2018-11-20 20:29 ` Anthony Towns
2018-11-21 11:20 ` Christian Decker
2018-11-21 17:55 ` Johnson Lau
2018-11-21 11:15 ` Christian Decker
2018-11-23 6:04 ` Anthony Towns
2018-11-23 9:40 ` Christian Decker
2018-11-24 8:13 ` Johnson Lau
2018-11-21 17:07 ` Russell O'Connor
2018-11-22 14:28 ` Johnson Lau
2018-11-22 16:23 ` Russell O'Connor
2018-11-22 20:52 ` Johnson Lau
2018-11-22 22:10 ` Russell O'Connor
2018-11-23 10:47 ` Johnson Lau
2018-11-23 5:03 ` Anthony Towns
2018-11-23 20:18 ` Russell O'Connor
2018-11-28 3:41 ` Pieter Wuille
2018-11-28 8:31 ` Johnson Lau
2018-11-29 17:00 ` Christian Decker
2018-11-29 18:29 ` Christian Decker
2018-12-06 16:57 ` Russell O'Connor
2018-12-09 19:13 ` Johnson Lau
2018-12-11 22:50 ` Russell O'Connor
2018-12-12 19:53 ` Johnson Lau
2018-12-13 16:50 ` Russell O'Connor
2018-12-13 0:05 ` Anthony Towns [this message]
2018-12-13 16:21 ` Russell O'Connor
2018-12-14 0:47 ` Anthony Towns
[not found] ` <CAAS2fgRma+Pw-rHJSOKRVBqoxqJ3AxHO9d696fWoa-sb17JEOQ@mail.gmail.com>
2018-12-13 16:34 ` Russell O'Connor
2018-12-09 22:41 ` David A. Harding
2018-12-11 15:36 ` Russell O'Connor
2018-12-11 17:47 ` David A. Harding
2018-12-12 9:42 ` Rusty Russell
2018-12-12 20:00 ` Johnson Lau
2018-12-12 23:49 ` Rusty Russell
2018-12-13 0:37 ` Rusty Russell
2018-12-14 9:30 ` Anthony Towns
2018-12-14 13:55 ` Johnson Lau
2018-12-17 3:10 ` Rusty Russell
2018-12-20 19:34 ` Johnson Lau
2018-12-20 23:17 ` Rusty Russell
2018-12-21 18:54 ` Johnson Lau
2018-12-23 4:26 ` Anthony Towns
2018-12-23 16:33 ` Johnson Lau
2018-12-24 12:01 ` ZmnSCPxj
2018-12-24 21:23 ` Johnson Lau
2018-12-16 6:55 ` Rusty Russell
2018-12-17 19:08 ` Johnson Lau
2018-12-18 4:22 ` Peter Todd
2018-12-19 0:39 ` Rusty Russell
2019-02-09 0:39 ` Pieter Wuille
2018-12-13 0:24 ` Anthony Towns
2018-11-28 0:54 Bob McElrath
2018-11-28 8:40 ` Johnson Lau
2018-11-28 14:04 ` Bob McElrath
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=20181213000553.cikilodf65an225g@erisian.com.au \
--to=aj@erisian$(echo .)com.au \
--cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
--cc=roconnor@blockstream$(echo .)io \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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