From: Timothy Newsham <newsham@wiliki.eng.hawaii.edu>
Date: Sun, 12 Sep 93 13:19:35 PDT
To: ccat@netcom.com (Chris Beaumont)
Subject: Re: encryption key switching,would it work?
In-Reply-To: <9309121608.AA08172@netcom5.netcom.com>
Message-ID: <9309122019.AA06312@toad.com>
MIME-Version: 1.0
Content-Type: text/plain


> 
> I'm wondering if there is any particular reason why an encrypted message
> might not be encrypted with several different keys,within the same message,
> divided by time.Perhaps synchronized clocks or time stamping might be used
> to toggle the encryption parameters.This technology might be able to defeat
> the brute force decryption technologies described in the paper mentioned
> yesterday.

If you have a system with key exchange you can change the keys on demand
in the middle of a stream (provided the protocol you use allows this).
This may be done as many times and as often as you please up to the
limitations of the (usually) slower key exchange protocol.

> Chris Beaumont                    nutrient cafe wholesale
> ccat@netcom.com                  MIME mail graciously accepted
> ccat@casa.stanford.edu           public key available via finger