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From: Arno Wagner <arno@wagner.name>
To: dm-crypt@saout.de
Subject: Re: [dm-crypt] Mastery Key and RAM burn-in
Date: Thu, 24 Oct 2019 02:16:02 +0200	[thread overview]
Message-ID: <20191024001602.GA15655@tansi.org> (raw)
In-Reply-To: <c7d2c5cb-c24c-b8d4-b9f8-fe9317e908f5@riseup.net>

Hi,

I would suggest that Gutmann's insights (which were pretty 
good when published) are pretty much outdated 18 years later.
Manufacturing processes have changed and cell stability is
vastly better than it was (or DRAMs would not survive very 
long). It is not clear whether these attacks still work and
how much effort they would be. 

This attack is not a widespread concern in the security 
community these days though. As far as I am aware (correct
me if I am wrong), there is not a single instance where
this attack was used successfully. 

Anyways, this is not a LUKS or dm-Crypt issue. This is an
issue with the kernel crypto services, I believe. loop-AES
is kind of historic and still did its own crypto. That is
not how things work these days.

Regards,
Arno


On Thu, Oct 24, 2019 at 00:23:47 CEST, procmem@riseup.net wrote:
> Hi. I've read Gutmann's papers about how data held persistently in DRAM
> can cause physical "burn-in" that makes master encryption key recovery
> trivial. His suggestion was to makes sure it is re-written/moved around
> every few minutes. [1] loop-aes had such a mitigation implemented,
> though it unfortunately aids cold boot attack key recovery.[2]
> 
> Does dm-crypt have mitigations for this in place?
> 
> [1] https://www.cs.jhu.edu/~astubble/600.412/s-c-papers/remanence.pdf
> 
> [2] https://www.lorentzcenter.nl/lc/web/2010/383/presentations/Heninger.pdf
> 
> 
> _______________________________________________
> dm-crypt mailing list
> dm-crypt@saout.de
> https://www.saout.de/mailman/listinfo/dm-crypt

-- 
Arno Wagner,     Dr. sc. techn., Dipl. Inform.,    Email: arno@wagner.name
GnuPG: ID: CB5D9718  FP: 12D6 C03B 1B30 33BB 13CF  B774 E35C 5FA1 CB5D 9718
----
A good decision is based on knowledge and not on numbers. -- Plato

If it's in the news, don't worry about it.  The very definition of 
"news" is "something that hardly ever happens." -- Bruce Schneier

  reply	other threads:[~2019-10-24  0:16 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-23 22:23 [dm-crypt] Mastery Key and RAM burn-in procmem
2019-10-24  0:16 ` Arno Wagner [this message]
  -- strict thread matches above, loose matches on Subject: below --
2019-10-25  0:00 procmem

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