cryptoanarchy.wiki

Arise, you have nothing to lose but your barbed wire fences!

1996-10-04 - DESCrack keyspace partitioning

Header Data

From: “geeman@best.com” <geeman@best.com>
To: “‘cypherpunks@toad.com>
Message Hash: 6a68c06452b97eb3c85906106bd924e8212800b3570e309342bf60911d45cacb
Message ID: <01BBB163.FC317940@geeman.vip.best.com>
Reply To: N/A
UTC Datetime: 1996-10-04 11:58:22 UTC
Raw Date: Fri, 4 Oct 1996 19:58:22 +0800

Raw message

From: "geeman@best.com" <geeman@best.com>
Date: Fri, 4 Oct 1996 19:58:22 +0800
To: "'cypherpunks@toad.com>
Subject: DESCrack keyspace partitioning
Message-ID: <01BBB163.FC317940@geeman.vip.best.com>
MIME-Version: 1.0
Content-Type: text/plain




What about the heuristics of partitioning the keyspace?

Seems to me that a _subset_ of all possible keys is much more likely
to appear than a random selection from an equidistributed population 0..2^56.

(P)RNG's just aren't that likely to produce a key of 010101010.....
nor 001100110011... etc etc and I have been thinking about how one might formalize 
and exploit this randomness property to increase the probability of finding the key sooner.

So a keysearch strategy should be something other than a partitioning of 2^26 into N bins
with a linear search within each bin.  I realize that it is POSSIBLE that a key of 1010101010...
was used, (excluding weak keys from consideration) ---- but I have seen "certifiable" RNG's and,
God Bless 'em, they just dont ever produce anything with any predictability.  

Is not the lack of predictability a predictable, and therefore exploitable, attribute?

Any thoughts here?




----------

Thread