[IP] Re: a comment from Ed Felten (and me) A Method for Critical Data Theft - New York Times

[David Farber <dave@farber.net>]

________________________________________
From: noah_mendelsohn@us.ibm.com [noah_mendelsohn@us.ibm.com]
Sent: Friday, February 22, 2008 10:42 AM
To: David Farber
Cc: ip
Subject: Re: [IP] a comment from Ed Felten (and me) A Method for Critical Data Theft - New York Times

A few hardware questions from a software person:

* How long does it take a typical single user machine to zero or store
garbage into memory on shutdown, using the fastest available CPU
instructions?  Last time I timed a 1 GHz Pentium machine with a hand coded
loop was in 2001, and it ran about 400MBytes, sec, if I recall correctly,
Servers and other machines could be different, but I think that  was
representative.  Assuming things have gotten a bit faster since then,
though probably not proportionally to CPU speed, am I right that a CPU
loop could reset a typical 2GByte memory in a few seconds at shutdown or
hibernate?

* Are there opportunities to do this yet  faster by doing something like
row-at-a-time resets at the chip level, presuming RAM chips were designed
to support such things?  (remember, I'm mainly a software person, so if
this is a bizarre question to ask, or if the chips already do it, my
apologies.)

I don't think such mechanisms would protect against every possible
scenario, but if I were landing at some airport and preparing to go
through customs, or leaving my home or office and worried about breakins,
I certainly wouldn't mind an extra 5 second delay on shutdown while the
RAMs were reset.  How close would such techniques come to protecting
against a threat like this (to the extent the threat is significant in
practice in the first place?)  Thanks

Noah

Noah Mendelsohn
IBM Corp.
Cambridge, MA





David Farber <dave@farber.net>
02/22/2008 09:57 AM
Please respond to dave

        To:     "ip" <ip@v2.listbox.com>
        cc:     (bcc: Noah Mendelsohn/Cambridge/IBM)
        Subject:        [IP] a comment from Ed Felten (and me) A Method
for Critical Data Theft - New York Times


BTW an interesting scenario is at Customs entering any country. Your
laptop is seized ----- djf



Begin forwarded message:

From: "Edward W. Felten" <felten@cs.princeton.edu>
Date: February 22, 2008 9:51:50 AM EST
To: "David Farber" <dave@farber.net>
Subject: Re: [IP] Re: A Method for Critical Data Theft - New York Times

I think Lee Dryburgh is missing the point of our work.

The whole point of disk encryption products is to protect the data on
a laptop drive if the laptop is lost or stolen, that is, if physical
security is breached.  Our work shows that popular disk encryption
products fail to do what people think they do.  An adversary with
physical access to a laptop using disk encryption can (usually)
extract all the encrypted information from the disk.

As a meta-comment, be careful about anybody who debunks an idea based
on "a quick read".  Would it be too much trouble to actually read our
paper before pronouncing it pointless?

On Fri, Feb 22, 2008 at 9:37 AM, David Farber <dave@farber.net> wrote:
>
>
> Begin forwarded message:
>
> From: David Farber <dave@farber.net>
> Date: February 22, 2008 9:18:57 AM EST
> To: "ip" <ip@v2.listbox.com>
> Subject: [IP] Re:    A Method for Critical Data Theft - New York Times
> Reply-To: dave@farber.net
>
>
>
>
> Begin forwarded message:
>
> From: "Lee Dryburgh" <dryburghl@gmail.com>
> Date: February 22, 2008 8:59:59 AM EST
> To: dave@farber.net
> Cc: ip <ip@v2.listbox.com>
> Subject: Re: [IP] A Method for Critical Data Theft - New York Times
>
> This has been all over the news today. It seems another unwarranted
> headline grabber (sorry to IP person whose work it is).
>
> The first point of security of data is physical security and from
> the quick
> read you need to push somebody away from their laptop, quickly spray
> the
> machine with something to cool it down very quick, hope the person
> did not
> disable booting from external drives (which you should do if running
> disk.
> encr.), and quickly boot from an external drive. If you can do to
> all that
> effort - I'd recommend installing a key logger - simpler with better
> results
> ;)
>
> Interesting and worthwhile research though.
>
> Regards
>
> Lee
>
> \ Emerging Comms Conference
> / March 12-14 - www.eCommMedia.com
> \ Skype: leedyburgh
>
> On 22/02/2008, David Farber <dave@farber.net> wrote:
>>
>>
>>
>> http://www.nytimes.com/2008/02/22/technology/22chip.html?hp
>>
>>
>> ________________________________
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>> Archives
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