From: Matt Thomlinson <phantom@u.washington.edu>
Date: Wed, 20 Apr 94 20:14:27 PDT
To: cypherpunks@toad.com
Subject: Re: myk-78
In-Reply-To: <Pine.3.89.9404202035.A8681-0100000@stein1.u.washington.edu>
Message-ID: <Pine.3.89.9404202023.A9260-0100000@stein1.u.washington.edu>
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I just sent this to a2@well.sf.ca.us (arthur abraham) but after a finger 
attempt, I'm not so sure his account exists there anymore. 


On Wed, 20 Apr 1994, Matt Thomlinson wrote:

> I'm reading through an old post of yours (gosh, 7 days from being a year 
> old) regarding the clipper chip. 
> 
> You laid everything out pretty carefully, but one thing your article 
> doesn't seem to mention:
> 
> you've created the LEEF [L1|L2|IV] and when transmitted in the block, it 
> looks like [encrypt(CV), checkword, L1|L2|IV], right? This is a 56+24+192 
> bit number ( = 272 bits). 
> 
> My question: how often is this chunk sent? seems like you'd only need to 
> send it once per call, but I'd think they'd send it every so often 
> throughout a call, although this could cause problems for high-bandwidth 
> digital uses, right?

Also, if someone could tell me if the checkword for the CV is encrypted 
along with the CV I'd be grateful. That is, is the packet
[encrypt(CV,checkword), L1|L....]
or
[encrypt(CV), checkword, L1|L...]

mt

Matt Thomlinson                               
University of Washington, Seattle, Washington.      phone: (206) 548-9804
Check my home page -- ftp://ftp.u.washington.edu/public/phantom/home.html 
PGP 2.2 key available via email, or finger phantom@hardy.u.washington.edu