Re: [Cfrg] Message Digest Algorithm Choice for CMS with Ed448

Ilari Liusvaara <ilariliusvaara@welho.com> Sun, 20 November 2016 05:56 UTC

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Date: Sun, 20 Nov 2016 07:56:14 +0200
From: Ilari Liusvaara <ilariliusvaara@welho.com>
To: Russ Housley <housley@vigilsec.com>
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Subject: Re: [Cfrg] Message Digest Algorithm Choice for CMS with Ed448
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On Sat, Nov 19, 2016 at 08:04:27PM -0500, Russ Housley wrote:
> > 
> > Also, I hope that there is some envelope around the raw SHAKE256
> > result. Otherwise the result is the same as Ed448ph, except without
> > the TBS collision protection w.r.t. Ed448.
> 
> I believe the ASN,1 encoding of the signed attributes provides the
> “envelope around” the SHAKE256-512 result.

Oh, indeed it does.


-Ilari