Date: Fri, 21 Oct 2016 10:52:02 -0700
From: Michael Halcrow <mhalcrow@google.com>
To: Richard Weinberger <richard@nod.at>
Cc: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, dedekind1@gmail.com,
        adrian.hunter@intel.com, tytso@mit.edu, jaegeuk@kernel.org,
        david@sigma-star.at, wd@denx.de, sbabic@denx.de, dengler@linutronix.de
Subject: Re: [PATCH 15/26] ubifs: Implement encrypt/decrypt for all IO
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On Fri, Oct 21, 2016 at 07:21:04PM +0200, Richard Weinberger wrote:
> On 21.10.2016 19:14, Michael Halcrow wrote:
> > Compress-before-encrypt is a hazard.
> > 
> > http://www.iacr.org/cryptodb/archive/2002/FSE/3091/3091.pdf
> 
> I'm fully aware of that. But as usual it depends on the use case.
> Compression is optional in UBIFS, paranoid users can disable it
> when encryption is enabled.

It's not the paranoid users I'm concerned about.  It's those building
systems with complexity and nuance on top of UBIFS who aren't paranoid
enough.

I suggest disabling compression by default when encryption is enabled,
unless the user explicitly enables both.

> 
> Thanks,
> //richard