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Re: Wiener paper (was Re: Comparing Cryptographic Key Sizes)
Adam Back wrote:
>
> Re comments that I should re-read the paper, here is what Wiener's
> paper says about estimated costs of a specialized DES key breaker:
>
> $100,000 for a machine to break DES in an average of 35 hrs
> $1 mil for a machine to break DES in an average of 3.5 hrs
> $10 mil for a machine to break DES in an average of 21 mins
>
> It was as Peter says published in 1993.
>
> Wiener also budgets for $500,000 in design costs (wages, parts, fab
> etc).
>
> Another interesting part of the design is that it is based on a
> pipelined chip, clocked at 50Mhz which can try 50 Million keys/sec.
>
> 35 hours sounds a reasonable amount of time to break a Swift banking
> transfer key protecting trillions of dollars of funds.
One thing that I haven't heard anybody mention yet is that if time is
important, you can break keys in an arbitrarily short period of time,
if there's a continuous sequence of transactions. Assume it takes 35
hrs to crack a key (with 50% probability), This means that you have a
1.4% chance to crack it in one hour. If you give up after an hour and
pick a new transaction to crack, you have a 50% chance of cracking at
least one transaction after 48 hours, and they will all have been
cracked in less than an hour.
--
What is appropriate for the master is not appropriate| Tom Weinstein
for the novice. You must understand Tao before | [email protected]
transcending structure. -- The Tao of Programming |