[tor-talk] NSA supercomputer

[Seth David Schoen]

Andrew F writes:

> You know, if anyone has an Nvidia Xk20 and an AMD 16 core working together,
> we could test on a small scale and then extrapolate from there, get an
> estimate of efficiency per second and do the calculations.  If anyone wants
> to mess around with it and has the hardware...  :-)  I'll buy the pizza and
> beer. In fact, It would be a fun article to write.    "So just how fast is
> the NSA supercomputer?"

I don't think that consumer hardware not intended for cryptographic use
is a great basis to estimate cracking speeds of specialized cryptoanalytic
devices.  If you think about bitcoin hash rates, custom hardware is already
clobbering GPUs, not only in overall speed, but also in cost-effectiveness
(hashing speed per dollar).  The same was true when EFF built the DES
cracker back in 1998 -- custom hardware was significantly more cost-effective
for fast DES cracking relative to ordinary desktop CPUs.

In fact (just following Wikipedia's figures, not my own recollections of the
_Cracking DES_ book), the EFF machine was about 90,000 times faster than a
desktop computer at the same time -- but probably only around 100 times the
cost.

Recommended key length is a topic that's seen fairly extensive study, often
based on speculating about an adversary's costs.

http://www.keylength.com/en/

I think there was a summary paper in the last couple of years trying to
estimate the cost of modern custom hardware to break keys of various sizes,
but I haven't been able to find it again.  The COPACOBANA hardware cracker
is a major milestone using readily-available commercial technology.  I
don't know what their current-generation machines do, but they roughly
matched EFF's cracker for about $10,000 in 2006 and I assume it's quite
a lot better now.  They use Xilinx FPGA chips, which is still not the most
cost-effective option for an organization like NSA which could have its
own microchip fabrication facilities.

-- 
Seth Schoen  <schoen at eff.org>
Senior Staff Technologist                       https://www.eff.org/
Electronic Frontier Foundation                  https://www.eff.org/join
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