Bugtraq mailing list archives
Re: passwd hashing algorithm
From: newsham () aloha net (Timothy Newsham)
Date: Fri, 21 Apr 1995 20:16:11 -1000 (HST)
My replies have always been in the context of what Shadow does for long passwords. Yes, there has been some confusion in this thread. I was, uh, quite shocked to see what David Wagner was really talking about because it is pretty obvious that it has security problems. Essentially, it removes the 1:1 cleartext to ciphertext relationship that some of us feel crypt() has. I don't know what the new relationship is, but its probably GodAwfulLarge to 1. Once you assume that there are GodAwfulMany passwords which yield the same result, the 2^56 brute force attack is much easier.
The posted data just shows that two strings with differing salts can hash to the same value (without the salt). This doesn't buy you anything since the salt is used in the compare when doing authentication. The post did not show that two passwords can hash to the same value while using the same salt (and it doesn't show that it can't either). Your second statement (...but its probably ...) seems to be based on nothing but pessimism.
John F. Haugh II [ NRA-ILA ] [ Kill Barney ] !'s: ...!cs.utexas.edu!rpp386!jfh Ma Bell: (512) 251-2151 [GOP][DoF #17][PADI][ENTJ] @'s: jfh () rpp386 cactus org
Tim N.
Current thread:
- Re: virus, (continued)
- Re: virus Leo Bicknell (Apr 22)
- no virus, only a rumor Albert Lunde (Apr 22)
- Re: no virus, only a rumor [good times, xxx-1] Matthew Hannigan (Apr 23)
- Good Times Paul Robinson (Apr 24)
- Re: virus Joshua Hosseinoff (Apr 23)
- Re: virus eli (Apr 23)
- The list Jon Green (Apr 23)
- Re: passwd hashing algorithm John F. Haugh II (Apr 20)
- Re: passwd hashing algorithm Charlie Watt (Apr 21)
- Re: passwd hashing algorithm John F. Haugh II (Apr 21)
- Re: passwd hashing algorithm Timothy Newsham (Apr 21)
- Re: passwd hashing algorithm John F. Haugh II (Apr 23)
- RE: virus Erich W. Gunther (Apr 23)
- Re: passwd hashing algorithm David Miller (Apr 19)
- Re: passwd hashing algorithm David A. Wagner (Apr 19)
- Re: passwd hashing algorithm John F. Haugh II (Apr 21)
- AntiFlash talkd Richard Allen (Apr 19)
- Re: AntiFlash talkd James M. Golovich (Apr 19)
- Password Storage as Environment Variable Bill Bradley (Apr 19)