Re: DFA

Paul Bell wrote:
>does anyone know what has happened to DFA, and the people who
>just a few months ago were publishing such encouraging results?

There seems be sustained investigation of DFA, offensive and defensive,
by Biham and Shamir, by Anderson and Kuhn, by the Bellcore team, by 
Quisquater and others.

However, the smartcard manufacturers appear to have a role in dampening 
publicity about the ongoing research, or at least diminishing the claims of 
effectiveness of DFA. Carol Francher, of Motorola, for example, writes
in February IEEE Spectrum:

   Technology is a wonderful thing but criminals, too, can use it as new 
   equipment and techniques become available or less expensive the 
   barriers to cracking a system may weaken. Recently Bellcore 
   announced a paper, "Cryptanalysis in the presence of hardware faults" 
   (available at www.bellcore.com), that proposed a theoretical method for
   breaking an asymmetric encryption code once a computer (or a 
   smartcard microcontroller) had been forced into faulty behavior.

   The Smart Card Forum, a multi-industry membership organization 
   headquartered in Tampa, Fla., has stated that it does not regard this 
   approach as a real-world risk, since in smartcard applications more 
   than one technique is used to protect the security of the entire system. 
   But the Bellcore methodology for breaking algorithms -- as well as 
   similar theoretical approaches, such as the one taken by two Israeli 
   researchers, Eli Biham and Adi Shamir -- highlights the need to 
   analyze and evolve the security of any system continually.

   -- "In your pocket: smartcards."  <http://jya.com/tee08.htm>

Several of the DFA-type researchers have commented on the smartcard 
industry's reluctance to publicize security weaknesses when the push is 
on to increase consumer trust and use; see, for example, Anderson and
Kuhn at:

  http://www.cl.cam.ac.uk/users/rja14/tamper.html

Quisquater and the SG group also note the reluctance of smartcard
mass-marketers to own up to security shortcomings of which their own
engineers know and fret.

Meanwhile, the DFA proponents and opponents are eagerly absorbing the 
continuing DFA-relatged reports, quietly watching one another, and both 
sides eying the booming smartcard market for lucrative rewards, as Ms. 
Francher suggests: licit and il.

At 1:29 pm -0500 on 2/16/97, John Young wrote:


> Paul Bell wrote:
> >does anyone know what has happened to DFA, and the people who
> >just a few months ago were publishing such encouraging results?
>
> There seems be sustained investigation of DFA, offensive and defensive,
> by Biham and Shamir, by Anderson and Kuhn, by the Bellcore team, by
> Quisquater and others.
>
> However, the smartcard manufacturers appear to have a role in dampening
> publicity about the ongoing research, or at least diminishing the claims of
> effectiveness of DFA.

At FC97 <http://www.offhsore.com.ai/fc97/> ;-), we have the following paper
at 10:45 on Tuesday February 22nd:


>     Fault Induction Attacks, Tamper Resistance, and Hostile Reverse
>         Engineering in Perspective
>     David P. Maher (AT&T Labs--Research, Murray Hill, NJ, USA)

I'm not sure whether which side of the fight this paper will be on, but it
could be easy to speculate from the title. :-).

On the other side of the coin, we invited Shamir to come talk about his DFA
work, but eventually it turned out that he couldn't make the trip. Maybe
next year. We *did* get Ron Rivest, though.

(Shameless plug: Our *other* invited speakers are Simon L. Lelieveldt of
the Dutch central bank, who'll talk about the security of electronic money,
and Peter Wayner, the author of "Digital Cash", who'll talk about money
laundering.) (*Really* shameless hucksterism: Since AA *didn't* strike,
they're offering mucho cheapseat deals to places like Anguilla and St.
Maarten, a short ferry ride away, even if you make your reservations on
really short notice. Like, maybe to go to FC97? Nudge, Nudge. We can also
get you *cheap* hotel rooms when you get there... Wink, wink, wink.)

Meanwhile, the FC97 workshop (which runs the week prior to the conference
itself) starts on Monday, and, having weathered the American Airlines
non-strike, Ian Goldberg, Adam Shostack and Gary Howland are now all down
in Anguilla getting things set up. I don't think people can get to *that*
in time, but, hey, you could *try*, I suppose. Better get packing, though,
'cause time is running out. The workshop starts at 09:00 tomorrow.
<http://www.offshore.com.ai/fc97/>

;-).

Cheers,
Bob Hettinga


-----------------
Robert Hettinga (rah@shipwright.com), Philodox
e$, 44 Farquhar Street, Boston, MA 02131 USA
"Never attribute to conspiracy what can be
explained by stupidity." -- Jerry Pournelle
The e$ Home Page: http://www.shipwright.com/rah/
FC97: Anguilla, anyone? http://www.ai/fc97/