From: thug@phantom.com (Murdering Thug)
To: tedwards@wam.umd.edu (technopagan priest)
Message Hash: b361a94585696363130b7ff8ecf5b4d9d34b5f70538b39522a56295b06964d4d
Message ID: <m0oEOUC-0009YyC@mindvox.phantom.com>
Reply To: <199307091816.AA09211@rac3.wam.umd.edu>
UTC Datetime: 1993-07-09 19:47:23 UTC
Raw Date: Fri, 9 Jul 93 12:47:23 PDT
From: thug@phantom.com (Murdering Thug)
Date: Fri, 9 Jul 93 12:47:23 PDT
To: tedwards@wam.umd.edu (technopagan priest)
Subject: Re: Hmm...hardware secure phone?
In-Reply-To: <199307091816.AA09211@rac3.wam.umd.edu>
Message-ID: <m0oEOUC-0009YyC@mindvox.phantom.com>
MIME-Version: 1.0
Content-Type: text
> I've been reading up on Codecs. Motorola has the MC145505 PCM Codec
> which samples at 8khz and the PCM output is at 64kbps. We can then
> use the MC145532 ADPCM Transcoder to reduce the data stream to
> 16kbps. With the breaks in spoken languages, perhaps we could get
> this to compress just enough to go through a 14.4 kbps modem.
How about just feeding the 16kbps stream to either a DES chip or a
microcontroller programmed for IDEA encryption/decryption? And don't
even bother with 14.4. Zyxel modems can do 16.8 & 19.2kbps full duplex.
But Zyxel's modulation is proprietary. A new standard called v.32terbo
has emerged which standardizes 16.8 and 19.2 modulation - I believe some
of AT&T's new modems support v.32terbo. Down the road a bit 21.6, 24.4 & 28.8
modulation (v.FAST) will be more common. The way I see it, the hassle of
squeezing 16kbps into a 14.4kbps bandwidth pipe is not worth the agrivation
when you can pipe it straight into a Zyxel or v.32terbo modem right now.
> Anyway, who knows of a DES or RSA chip which will do 16kbps?
They all do, some chips even go as high as several megabits per second for
DES. I don't know of any chips that do RSA though.
> Then all we need is a microcontroller to run the show, and
> perform D-H or RSA key exchange.
Exactly.
---
thug@phantom.com
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