From: "Russell O'Connor" <roconnor@blockstream•io>
To: Mark Friedenbach <mark@friedenbach•org>,
Bitcoin Protocol Discussion
<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] Fast Merkle Trees
Date: Wed, 6 Sep 2017 21:59:54 -0400 [thread overview]
Message-ID: <CAMZUoKmD4v4vn9L=kdyJNk-km3XHpNVkD_tmS+SseMsf6YaVPg@mail.gmail.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 832 bytes --]
The fast hash for internal nodes needs to use an IV that is not the
standard SHA-256 IV. Instead needs to use some other fixed value, which
should itself be the SHA-256 hash of some fixed string (e.g. the string
"BIP ???" or "Fash SHA-256").
As it stands, I believe someone can claim a leaf node as an internal node
by creating a proof that provides a phony right-hand branch claiming to
have hash 0x80000..0000100 (which is really the padding value for the
second half of a double SHA-256 hash).
(I was schooled by Peter Todd by a similar issue in the past.)
On Wed, Sep 6, 2017 at 8:38 PM, Mark Friedenbach via bitcoin-dev <
bitcoin-dev@lists•linuxfoundation.org> wrote:
> Fast Merkle Trees
> BIP: https://gist.github.com/maaku/41b0054de0731321d23e9da90ba4ee0a
> Code: https://github.com/maaku/bitcoin/tree/fast-merkle-tree
>
[-- Attachment #2: Type: text/html, Size: 1497 bytes --]
next reply other threads:[~2017-09-07 2:00 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-07 1:59 Russell O'Connor [this message]
2017-09-07 2:20 ` Mark Friedenbach
2017-09-07 15:43 ` Russell O'Connor
2017-09-07 17:42 ` Mark Friedenbach
2017-09-07 18:55 ` Russell O'Connor
2017-09-07 20:04 ` Mark Friedenbach
2017-09-12 11:44 ` Johnson Lau
2017-09-07 5:55 ` Peter Todd
2017-09-07 15:51 ` Russell O'Connor
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='CAMZUoKmD4v4vn9L=kdyJNk-km3XHpNVkD_tmS+SseMsf6YaVPg@mail.gmail.com' \
--to=roconnor@blockstream$(echo .)io \
--cc=bitcoin-dev@lists$(echo .)linuxfoundation.org \
--cc=mark@friedenbach$(echo .)org \
/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