[Full-disclosure] Comparing Algorithms On The List OfHard-to-brut-force?

[Andrew Farmer]

On 01 Nov 05, at 10:11, Brandon Enright wrote:
> Brute forcing an algorithm suggests that you are not attacking a  
> weakness or
> known flaw in the algorithm but rather just running through the  
> keyspace
> trying to recover the plaintext.  In that case, whichever allows  
> you to use
> the most bits is what you want.

Note that the encryption speed of an algorithm is *not* a significant  
factor
in the time taken to brute-force it, except for extremely small  
keyspaces!
Remember that the time taken to brute-force an N-bit algorithm that  
takes K
seconds per encryption is, on average

         N
    K * 2

which increases much more rapidly with N than it does with K. Adding  
even one
more bit will double the average time taken to brute-force an  
algorithm, while
using a slower algorithm will only increase the difficulty marginally.

Also note that anything beyond 256 bits is silly. Brute-forcing a 256- 
bit
algorithm can be shown to be PHYSICALLY impossible, so there's no  
reason to
go anywhere beyond that.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: PGP.sig
Type: application/pgp-signature
Size: 186 bytes
Desc: This is a digitally signed message part
Url : http://lists.grok.org.uk/pipermail/full-disclosure/attachments/20051101/d90d6a8d/attachment.bin