[82395] in Cypherpunks
Wiener paper (was Re: Comparing Cryptographic Key Sizes)
daemon@ATHENA.MIT.EDU (Adam Back)
Tue Jun 24 15:52:18 1997
Date: Tue, 24 Jun 1997 18:54:42 +0100
From: Adam Back <aba@dcs.ex.ac.uk>
To: davidlu@sco.COM
Cc: trei@process.com, cypherpunks@cyberpass.net
In-Reply-To: <3.0.2.32.19970624162104.007bb990@middx.x.co.uk> (message from
David Lucas on Tue, 24 Jun 1997 16:21:04 +0100)
Reply-To: Adam Back <aba@dcs.ex.ac.uk>
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.
Perhaps $10,000 isn't too far off the current day costs of breaking
DES after all. (500Mhz chips? You can get dec alphas at that speed,
and thats a general purpose CPU)
(If anybody is short of a copy, I've put the one up I've got (no idea
where I got it from) here:
http://www.dcs.ex.ac.uk/~aba/crypto-papers/des_key_search.ps
)
Adam
--
Have *you* exported RSA today? --> http://www.dcs.ex.ac.uk/~aba/rsa/
print pack"C*",split/\D+/,`echo "16iII*o\U@{$/=$z;[(pop,pop,unpack"H*",<>
)]}\EsMsKsN0[lN*1lK[d2%Sa2/d0<X+d*lMLa^*lN%0]dsXx++lMlN/dsM0<J]dsJxp"|dc`
