Re: RC5-12/32/5 contest solved

Jim Bell rote:
>Assuming it's possible to build a chip which tests solutions in a 
>massively-pipelined mode, the 400,000 or so solutions per second tried (for 
>what is probably a $2000 machine) would probably increase to 100 million per 
>second per chip (at a cost of maybe $100 per chip, if implemented in 
>parallel).    That's 5000 times more economical,  which would translate to a 
>find in 2-3 days if the same dollars in hardware were invested.

Hi Jim, still on your list 8*)

Funny thing is that 3 1/2 hours for a 40 bit search is the "real world"
number I was using two years ago (can look it up in various archives)
so is interesting that the first real test came out exactly the same.

Is why I said 40 bits should not protect anything worth more than U$250.00

Have good reason to believe your estimate for a purpose built machine this
year (expect 600,000,000 to 1,000,000,000 kps per sieve - these will not 
be cheap chips but will be commecially available). Expect 400 arrays
would be required to do DES in a day (average) but is a lot more
achievable than the 65k postulated by the gang of nine.

Still would not be too concerned about using DES so long as every message 
encrypted (including orders for a tuna on rye) and each uses a different
key - is "security by obscurity" in a way but am comfortable with it.

Besides, if really concerned will just superencrypt.

					Warmly,
						Padgett

	"I love it when a plan comes together."

A. Padgett Peterson P.E. Information Security apparently wrote:
> Have good reason to believe your estimate for a purpose built machine this
> year (expect 600,000,000 to 1,000,000,000 kps per sieve - these will not 
> be cheap chips but will be commecially available). Expect 400 arrays
> would be required to do DES in a day (average) but is a lot more
> achievable than the 65k postulated by the gang of nine.

I received a nice flyer in the mail the other day from "Chip Express"
(www.chipexpress.com, 800-95-CHIPX). They are offering Laser
Programmed Gate Arrays.  It appears to be a reasonable way to get some
Wiener chips built.  As I recall, the Wiener design required about
23,000 gates.  Their blurb had the following table in in:

  FPGA Gates  ASIC Gates  500 Units  1000 Units  5000 Units
    40,000      20,000      $77        $45         $10
   Not Avail   200,000     $176       $150         $82

So it appears that you can get 5000 Wiener key search chips build for
about $50K.  I'm not sure about the speed, but I wouldn't be surprised
if you could clock these at 50 MHz.  The Wiener design is pipelined
and searches one key per clock, so each chip could search 50e6 keys /
second.  50e6 * 5000 = 250e9 keys / second for $50K

Happy Hunting...

Eric