public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: "Russell O'Connor" <roconnor@blockstream.io>
To: Johnson Lau <jl2012@xbt.hk>,
	 Bitcoin Protocol Discussion
	<bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] SIGHASH2 for version 1 witness programme
Date: Fri, 1 Jun 2018 11:03:46 -0400	[thread overview]
Message-ID: <CAMZUoKms85DhtS1mN70nq4LSY7QtXym6E4_yvQk5Q0tizkVwEQ@mail.gmail.com> (raw)
In-Reply-To: <9CCCE945-9432-41B9-8559-AFE7CF233603@xbt.hk>

[-- Attachment #1: Type: text/plain, Size: 793 bytes --]

On Thu, May 31, 2018 at 2:35 PM, Johnson Lau via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

>
>   Double SHA256 of the serialization of:
>

Should we replace the Double SHA256 with a Single SHA256?  There is no
possible length extension attack here.  Or are we speculating that there is
a robustness of Double SHA256 in the presence of SHA256 breaking?

I suggest putting `sigversion` at the beginning instead of the end of the
format.  Because its value is constant, the beginning of the SHA-256
computation could be pre-computed in advance.  Furthermore, if we make the
`sigversion` exactly 64-bytes long then the entire first block of the
SHA-256 compression function could be pre-computed.

Can we add CHECKSIGFROMSTACK or do you think that would go into a separate
BIP?

[-- Attachment #2: Type: text/html, Size: 1192 bytes --]

  reply	other threads:[~2018-06-01 15:04 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-31 18:35 [bitcoin-dev] SIGHASH2 for version 1 witness programme Johnson Lau
2018-06-01 15:03 ` Russell O'Connor [this message]
2018-06-01 17:03   ` Johnson Lau
2018-06-01 18:15     ` Russell O'Connor
2018-06-01 18:45       ` Johnson Lau
2018-07-02 18:23 ` Gregory Maxwell
2018-08-30 20:38 ` Johnson Lau
2018-08-30 20:51   ` Christian Decker
2018-08-31  7:42     ` Johnson Lau
2018-09-03 13:53       ` Christian Decker

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=CAMZUoKms85DhtS1mN70nq4LSY7QtXym6E4_yvQk5Q0tizkVwEQ@mail.gmail.com \
    --to=roconnor@blockstream.io \
    --cc=bitcoin-dev@lists.linuxfoundation.org \
    --cc=jl2012@xbt.hk \
    /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