Re: [MLS] Use Cases for avoiding Forward Secrecy

Eric Rescorla <ekr@rtfm.com> Fri, 02 March 2018 14:52 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Fri, 2 Mar 2018 06:51:08 -0800
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To: Dave Cridland <dave@cridland.net>
Cc: Russ Housley <housley@vigilsec.com>, mls@ietf.org
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Subject: Re: [MLS] Use Cases for avoiding Forward Secrecy
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On Fri, Mar 2, 2018 at 1:51 AM, Dave Cridland <dave@cridland.net> wrote:

> On 1 March 2018 at 15:11, Russ Housley <housley@vigilsec.com> wrote:
> > This is similar to the approach used in some email environments.  The
> email
> > message is decrypted for reading, and then encrypted in a separate
> archive
> > key for storage.
>
> Sure, but that explicitly means that messages within the archive can
> no longer be authenticated, doesn't it?
>

Not if they are digitally signed, which is an explicit option in the
current drafts.

-Ekr



That, in turn, is a clear downgrade from the NCSC's SAKKE dictat. For
> all its faults, that is providing a secure archive that the enterprise
> has access to via an offline key escrow.
>
> If I'm wrong here please don't hesitate to correct me.
>
> Dave.
>
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