Re: Non-PK encryption not vulnerable via low key length?!

[mgscheue () Oakland edu (Mark G. Scheuern)]

On Wed, 15 Mar 1995, Jonathan Cooper wrote:

> Date: Wed, 15 Mar 1995 20:35:44 -0500 (EST)
> From: Jonathan Cooper <entropy () IntNet net>
> To: Vishy Gopalakrishnan <vishy () sph umich edu>
> Cc: bugtraq () fc net
> Subject: Non-PK encryption not vulnerable via low key length?! 
>    You are wrong.
>
>    If the key is only 128-bit, that's a much smaller keyspace to 
> brute-force attack than a 1024-bit key.
>
>    (do the math)
>
> -jon

Okay, let's see. 2^128 = 3.4e38.  Suppose you can somehow try one
billion keys per second.  Then it will take you 3.4e29 seconds or
about 1e22 years to try every possible key.  A shorter length of
time than it would take with a 1024 bit key, but I don't think I'd
lose much sleep over it.

Mark

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