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Message-ID: <533163885.20070321235937@SECURITY.NNOV.RU>
Date: Wed, 21 Mar 2007 23:59:37 +0300
From: 3APA3A <3APA3A@...URITY.NNOV.RU>
To: Blue Boar <BlueBoar@...evco.com>
Cc: full-disclosure <full-disclosure@...ts.grok.org.uk>,
Secure Coding <SC-L@...urecoding.org>
Subject: Re: Chinese Professor Cracks Fifth Data Security
Algorithm (SHA-1)
Dear Blue Boar,
It's not clear if this 'crack' cam be applied to birthday attack. My
in-mind computations were: because birthday attack requires ~square root
of N computations where bruteforce requires ~N/2, impact of 2000 times N
decrease for birthday is ~64 times faster. 64 = 2^6. Because complexity
is ~square root of possible combinations, it's equivalent of traditional
birthday attack, with 160-(2*6)=148 bits hash (150 is my mistake in
in-mind computations).
Of cause, since I completely wasted 10 years after obtaining Master
degree in Mathematics and 3 years after loosing last pencil I may be
completely wrong in computations :)
--Wednesday, March 21, 2007, 9:48:55 PM, you wrote to 3APA3A@...URITY.NNOV.RU:
BB> 3APA3A wrote:
>> I know meaning of 'hash function' term, I wrote few articles on
>> challenge-response authentication and I did few hash functions
>> implementations for hashtables and authentication in FreeRADIUS and
>> 3proxy. Can I claim my right for sarcasm after calling ability to
>> bruteforce 160-bit hash 2000 times faster 'a crack'?
BB> Fair enough, your sarcasm tags didn't render properly in my MUA. I was
BB> fooled by you stating that the birthday attack would be 150 bits.
BB> BB
--
~/ZARAZA http://securityvulns.com/
Íåïðèÿòíîñòè íà÷íóòñÿ â âîñåìü. (Òâåí)
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