Full Disclosure mailing list archives
Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1)
From: Blue Boar <BlueBoar () thievco com>
Date: Wed, 21 Mar 2007 14:24:03 -0700
My understanding that the kind of birthday attack under discussion would start at 80-bits if SHA-1 (at 160-bits) were 100% secure. The attack under discussion is reported to reduce that to the neighborhood of 60-something bits. I am not a mathematician though, so I would be perfectly willing to believe I was wrong about that. BB 3APA3A wrote:
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 () SECURITY 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
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Current thread:
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1), (continued)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) Tim (Mar 21)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) 3APA3A (Mar 21)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) Valdis . Kletnieks (Mar 21)
- Re: Chinese Professor Cracks Fifth Data SecurityAlgorithm (SHA-1) Dave "No, not that one" Korn (Mar 22)
- Re: Chinese Professor Cracks Fifth Data SecurityAlgorithm (SHA-1) Michael Silk (Mar 23)
- Re: Chinese Professor Cracks Fifth Data SecurityAlgorithm (SHA-1) Dude VanWinkle (Mar 24)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) Tim (Mar 21)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) Blue Boar (Mar 21)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) 3APA3A (Mar 21)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) Blue Boar (Mar 21)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) 3APA3A (Mar 21)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) Blue Boar (Mar 21)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) 3APA3A (Mar 21)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) wac (Mar 24)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) Valdis . Kletnieks (Mar 24)
- Re: Chinese Professor Cracks Fifth Data Security Algorithm (SHA-1) wac (Mar 25)