[42408] in Cypherpunks
Re: MD4-derived hash functions
daemon@ATHENA.MIT.EDU (John Lull)
Fri Oct 27 00:16:12 1995
From: John Lull <lull@acm.org>
To: hallam@w3.org
Cc: cypherpunks@toad.com
Date: Fri, 27 Oct 1995 04:10:56 GMT
On Thu, 26 Oct 1995 12:03:57 -0400, you wrote:
> 3DES with only two independent keys is only slightly more secure than
> DES, consider a variant of the meet in the middle attack exploiting
> the fact that the constraint network is reductible to two equations
> in one unknown.
I believe you meant 2DES? I've not heard of a meet in the middle
attack on 2-key 3DES better than brute force of a 112-bit key.
Even for 2DES, or for 3-key 3DES, doesn't a meet in the middle attack
require on the order of 2^56 words of memory? This, as a practical
matter, makes a brute-force attack much more difficult than it would
appear at first glance.
