From kelly Mon May 03 06:24:09 0700 1993 remote from pleiku To: toad.com!cypherpunks Subject: Date: Mon, 03 May 1993 06:24:09 -0700 From: "Stop the Big Brother CHip" <pleiku!kelly> Received: from pleiku by pleiku.netcom.com; Mon, 3 May 1993 06:24 PDT Content-Type: text Content-Length: 3949

I thought this my be interesting to those designing encrypted phones... cheers kelly ------- Forwarded Message Return-Path: <kelly> Received: by netcom.netcom.com (5.65/SMI-4.1/Netcom) id AA21283; Sun, 2 May 93 10:25:08 -0700 Date: Sun, 2 May 93 10:25:08 -0700 From: kelly (Kelly Goen) Message-Id: <9305021725.AA21283@netcom.netcom.com> To: junem, kelly, phil Subject: quaderno Speech capabilities Status: R Path: netcom.com!csus.edu!news.ucdavis.edu!agate!howland.reston.ans.net!usc!cs.utexas.edu!uunet!psgrain!ee.und.ac.za!csir.co.za!nuustak!duck From: duck@nuustak.csir.co.za (Paul Ducklin) Newsgroups: comp.sys.palmtops Subject: Re: Quaderno speech hardware Date: 22 Apr 1993 10:01:03 +0200 Organization: CSIR, South AFrica Lines: 54 Message-ID: <duck.735462694@nuustak> References: <1993Apr20.213938.26184@Princeton.EDU> NNTP-Posting-Host: nuustak.csir.co.za X-Disclaimer: None of the opions expressed herein are the official X-Disclaimer: opinions of the CSIR or any of its subsidiaries. X-Disclaimer: ** So don't freak out at _us_ about anything ** Thus spake mg@cs.princeton.edu (Michael Golan): [stuff about the Quaderno's sound digitising capability]

Can the mic/speaker be accessed from software to produce 8-12bit digital sound? If so, and assuming a 9600bps modem is available (is it?), the machine is an excellent candidate for a truly secure phone

The speech DSP hardware is quite fancy -- you can download your own vocoder program, if you have the right DSP code development tools, to implement things like DTMF-recognition. Or you can select one of the built-in vocoders, which provide various levels of compression. The speech program which comes with the Quaderno is just a TSR which hooks to the speech hardware, and which writes digitised sound to a file. No reason why you couldn't write your own speech program which grabs digitsed blocks from the DSP [you can give the BIOS the address of a routine to be called when the DSP is ready to deliver] and stuffs them wheresoever you desire -- such as into the serial port. On the other end, you have a DSP "play" program -- once again, you can give the system the address of a routine to be called whenever the DSP is ready to analogise [?] the next block of bits. I can't remember, though, what bit-rates are available with the built-in vocoders. If people are interested, I'll look it up when I get home this evening [or Don Herrick -- are you there?]. Ah yes -- just remembered that one of the vocoders churns out 13Kbit/sec with *very* acceptable quality [for voice -- music sounds like a heap o' crap when pushed through this particular vocoder]. So this could be stuffed into a regular V.32bis modem and transmitted fast enough to give real-time speech. With its 16MHz V30 CPU, the Quaderno should be more than ready for the task of real-time encryption in software. If my memory serves me, there's also a built-in vocoder which compresses to 2400bits/sec [!] -- the speech program which ships with the Quaderno, however, doesn't offer this as an option, so I've yet to try it. Probably pretty damn bad, though. Another thought -- the Quaderno's DSP will record and play at the same time, and V.32bis is full-duplex. So full-duplex conversations on the above scheme are quite possible. Could be fun -- how to turn a good 3KHz analogue voice line into a fair 13Kbit digital voice line! And, as mentioned recently in alt.security, you can also use the speech digitiser for acquiring data with a high degree of randomness, which you then encrypt with a part of itself to produce data which is "truly" random. Paul /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ \ Paul Ducklin duck@nuustak.csir.co.za / / CSIR Computer Virus Lab + Box 395 + Pretoria + 0001 S Africa \ \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/ ------- End of Forwarded Message