Bugtraq mailing list archives
Re: passwd hashing algorithm
From: jfh () rpp386 cactus org (John F. Haugh II)
Date: Tue, 18 Apr 95 21:52:19 CDT
1. 25 iterations of DES with the first 8 bytes of the password as key, followed by 25 iterations of DES with the second 8 bytes of password as key. 2. repeat 25 times: an iteration of DES with the first 8 bytes of the password as key, followed by an iteration of DES with the second 8 bytes of password as key. (1) can be broken on a workstation with ~ 2^32 steps (and very little in the way of memory);
I've never seen anything resembling a convincing argument for this point. SecureWare uses a mechanism similar to this and it is part of one of their security offerings. I've used a slightly different, but similar, approach for several years and except for people noting that the second half of the encrypted string is very vulnerable, no one has ever shown it to be significantly less strong than a single route of 8 byte crypt() ala current practice. What I will concede is that 1) leaves you with a password function not much more than twice as strong as crypt() was to begin with. This is because, as you point out, DES is a block cipher. I do believe that there are better approaches to 1) that still use DES, and I'm very keen on sticking with crypt() for compatibility reasons. -- 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
Current thread:
- Re: passwd hashing algorithm, (continued)
- Re: passwd hashing algorithm Timothy Newsham (Apr 17)
- Re: passwd hashing algorithm Louis Taber (Apr 13)
- Re: passwd hashing algorithm maquis (Apr 14)
- Re: passwd hashing algorithm John F. Haugh II (Apr 16)
- Re: passwd hashing algorithm Charles Howes (Apr 14)
- Re: passwd hashing algorithm maquis (Apr 14)
- Re: passwd hashing algorithm der Mouse (Apr 14)
- Re: passwd hashing algorithm smb () research att com (Apr 14)
- Re: passwd hashing algorithm Dennis Glatting (Apr 15)
- Re: passwd hashing algorithm smb () research att com (Apr 16)
- Re: passwd hashing algorithm David A. Wagner (Apr 17)
- Re: passwd hashing algorithm John F. Haugh II (Apr 18)
- Re: passwd hashing algorithm David A. Wagner (Apr 18)
- Re: passwd hashing algorithm Charlie Watt (Apr 19)
- Re: passwd hashing algorithm Tom Fitzgerald (Apr 19)
- Re: passwd hashing algorithm Charlie Watt (Apr 20)
- The Dan Farmer rap Julian Assange (Apr 17)
- Re: The Dan Farmer rap Jonathan M. Bresler (Apr 20)
- Re: The Dan Farmer rap John Evans (Apr 20)
- Re: The Dan Farmer rap James O Ausman (Apr 21)
- Re: passwd hashing algorithm David A. Wagner (Apr 17)
- Re: The Dan Farmer rap Aleph One (Apr 20)
- Re: The pitiful rap Everett F Batey WA6CRE (Apr 21)