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
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A. Padgett Peterson P.E. Information Security -
Eric Blossom