[cryptography] Current state of brute-forcing random keys?

Marsh Ray marsh at extendedsubset.com
Thu Jun 9 23:30:50 EDT 2011


On 06/09/2011 09:34 PM, Sandy Harris wrote:
>
> One indicator is the Copacobana machine, built from FPGAs, The first
> version a few years back cost 9,000 euro and broke DES in a week.
> There's a later version. http://www.copacobana.org/

This box was from a few years ago:
http://picocomputing.com/pdf/PR_Pico_DES_BH_Jan_29_2010.pdf
It does 280e9 full DES ops per second which would find a 56-bit key in
36 hours on average.

I don't know the price but I did see it at Black Hat and the hardware
looked rather simple, PC rack chassis, etc. So the cost would likely be
predominated by the FPGAs.

> Of course a bunch of those in parallel could break it faster. That's
> a 56-bit key. 64-bit is 256 times harder, but certainly within reach
> of an attacker with large resources.  Judging solely by this, only
> someone with a huge budget, such as a major nation's intelligence
> agency, could afford to attack 80-bit keys.

Or someone who didn't pay their own power bill. Sony (or an attacker who 
pwned them) could have the largest supercomputer on the planet by far by 
just pushing down a PS3 firmware update.

- Marsh



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