[29107] in cryptography@c2.net mail archive
classical crypto programmatic aids
daemon@ATHENA.MIT.EDU (Travis H.)
Wed Jun 28 08:56:23 2006
X-Original-To: cryptography@metzdowd.com
X-Original-To: cryptography@metzdowd.com
Date: Tue, 27 Jun 2006 17:49:21 -0500
From: "Travis H." <solinym@gmail.com>
To: Cryptography <cryptography@metzdowd.com>
Hi folks,
Does anyone here know of any computer-based aids for breaking
classical cryptosystems? I'm thinking in particular of the ones in
"Body of Secrets", which are so short that I really hope they're
monoalphabetic substitutions. But I'm interested in these sorts of
programs more generally. I could use paper, but it'd be nice if a
computer could keep track of what I've tried and otherwise ruled out.
I am aware of the "crypt breaker's workbench", but that's specific to
classic Unix crypt(3). What else is there?
Incidentally, if anyone's interested, on my web page I have an article
on how I used classical techniques to recover files encrypted with CFS
and corrupted by disk failure or human error. It's sort of a rambling
stream-of-consciousness that I wrote while learning CFS and breaking
the encryption. It's not often that one gets to use classical methods
against a modern cryptosystem, so I figure it may be refreshing. To
summarize, CFS XORs each file against an eight-byte IV that is stored
as a dangling symlink, and on my system the symlinks had become
desynchronized from the files.
PDF: http://www.usenix.org/publications/login/2004-08/pdfs/howard.pdf
TXT: http://www.lightconsulting.com/~travis/cfs_travails.txt
--
"I sometimes have delusions of adequacy" -- Woody Allen
Security "guru" for rent or hire - http://www.lightconsulting.com/~travis/ -><-
GPG fingerprint: 9D3F 395A DAC5 5CCC 9066 151D 0A6B 4098 0C55 1484
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