From: Peter Todd <pete@petertodd•org>
To: "Russell O'Connor" <roconnor@blockstream•io>
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] A Method for Computing Merkle Roots of Annotated Binary Trees
Date: Tue, 27 Jun 2017 00:13:08 -0400 [thread overview]
Message-ID: <20170627041308.GA23776@savin.petertodd.org> (raw)
In-Reply-To: <CAMZUoK=8xaVp2Qoc7kvx8FdPbpY0rEpSba8kQVRQGjX4p0haxg@mail.gmail.com>
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On Mon, May 29, 2017 at 10:55:37AM -0400, Russell O'Connor wrote:
> > This doesn't hold true in the case of pruned trees, as for the pruning to
> > be
> > useful, you don't know what produced the left merkleRoot, and thus you
> > can't
> > guarantee it is in fact a midstate of a genuine SHA256 hash.
> >
>
> Thanks for the review Peter. This does seem like a serious issue that I
> hadn't considered yet. As far as I understand, we have no reason to think
> that the SHA-256 compression function will be secure with chosen initial
> values.
Relevant: fixed points can be found for the SHA256 compression function, if the
attacker can control the IV:
https://crypto.stackexchange.com/questions/48580/fixed-point-of-the-sha-256-compression-function
--
https://petertodd.org 'peter'[:-1]@petertodd.org
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prev parent reply other threads:[~2017-06-27 4:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-22 7:05 Russell O'Connor
2017-05-22 14:05 ` Peter Todd
2017-05-22 22:32 ` Russell O'Connor
2017-05-27 17:41 ` Peter Todd
[not found] ` <CAMZUoKkS8azx7Gooo3D+H_gdGdTNiNtwwNVbvU0u7HzOfdUSBg@mail.gmail.com>
2017-05-27 22:07 ` Russell O'Connor
2017-05-23 6:06 ` Bram Cohen
2017-05-28 8:26 ` Peter Todd
2017-05-29 14:55 ` Russell O'Connor
2017-05-29 16:10 ` Peter Todd
2017-06-01 15:10 ` Russell O'Connor
2017-06-27 4:13 ` Peter Todd [this message]
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