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From: jhs@Mitre-Bedford@sri-unix.UUCP
Newsgroups: net.ham-radio
Subject: Re: White House radios prevent eavesdrop - (nf)
Message-ID: <12736@sri-arpa.UUCP>
Date: Thu, 23-Aug-84 12:07:00 EDT
Article-I.D.: sri-arpa.12736
Posted: Thu Aug 23 12:07:00 1984
Date-Received: Thu, 30-Aug-84 01:12:05 EDT
Lines: 9

The White House voice privacy radios are probably from Motorola.  If so, they
use 12 Kbps "CVSD" or Continuously Variable Slope Delta Modulation, with a
DES-based encryption algorithm which Motorola has implemented in custom CMOS
for this purpose.  Or it may be a Motorola proprietary algorithm, as they have
done some in-house work on other approaches to commercial encryption.
In any case, it is NOT just a frequency inverter.

					73,
					de W3IKG