Re: More than 128 Bit

["Eric M. Hopper" <hopper,AT,omnifarious,DOT,org>]

On Sun, 2003-06-08 at 11:59, Tomasz Ciolek wrote:
> Why would you want more than 128 bit blowfish? If you want a larger
> cipher block, perhaps porting AES 192/256 into cipe would be better for
> you. AES algorithm would be better for that prupose, comnpute wise...

More than 256 bits of key is pointless.  Even if you have something that
halves the effective keylength, it's still uncomputable in any
reasonable period of time.  128 bit is pretty secure even if you talk
about theoretic computing limits in terms of the minimum energy required
to accomplish a state change in a fundamental particle, and positing an
average 2^(keylen = 1) state changes before a key brute-forced.

Of course, there is the problem of a limited number of blocks being able
to be encrypted with a key before you start leaking information.  But
CIPE handles that problem pretty well already by changing keys
regularly.

Have fun (if at all possible),
-- 
The best we can hope for concerning the people at large is that they
be properly armed.  -- Alexander Hamilton
-- Eric Hopper (hopper,AT,omnifarious,DOT,org  
http://www.omnifarious.org/~hopper) --

Attachment: signature.asc
Description: This is a digitally signed message part