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Re: Brute-forcing DES
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On Mon, 22 Jul 1996, Mike Duvos wrote:
> Date: Mon, 22 Jul 1996 23:33:58 -0700 (PDT)
> From: Mike Duvos <[email protected]>
> To: [email protected]
> Subject: Re: Brute-forcing DES
>
> "Peter Trei" <[email protected]> writes:
>
> > Sadly, after further calculation, I'm not so sure if it's
> > doable just yet.
>
> ....
>
> > The fastest general purpose, freely available des
> > implementation I'm aware of is libdes. by Eric Young. With
> > this, I can do a set_key in 15.8 us, and an ecb_encrypt in
> > 95 us/block. That adds up to about 9,000 keytests/sec (this
> > is on a 90 MHz P5, running NT).
>
> What you really want to do to sweep the DES keyspace is to
> "schedule" the input and output block you are testing, performing
> any static operations, and do only enough computation to see that
> a given key fails. Special purpose assembler to do this
> particular function would probably run faster than any algorithm
> which could also be employed to encrypt data.
>
> > What will make this brute doable, if not now, then in the
> > near future?
>
> > 1. Faster Processors
>
> > 2. More processors.
>
> > 3. More interest
>
> 4. Better code.
>
We also need to address the question of the code itself. Just crypting it
won't work. We need a good way to test _to see if we have an answer_, for
a non-known plaintext attack.
--Deviant
Whatever occurs from love is always beyond good and evil.
-- Friedrich Nietzsche
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